Nutritional and Lighting Manipulations

Selected Websites



Agcanas PB (1971). Observation on the effect of forced-molting of single combed White Leghorn hens due to an abrupt change of feeds. Philippine Journal of Animal Industry 28(1/4): 15-18.

NAL Call Number: 49.9 P53P


Ahmed N; Zia-ur-Rahman; Akram M; Shah TH; Yousaf M (1995). Effect of a new molting program on productive performance of spent layers under indigenous conditions. Pakistan Veterinary Journal 15(1): 46-48

Department of Poultry Science, University of Agriculture, Faisalabad-38040, Pakistan

            NAL Call Number: SF604 P32

During the 1st week of Dec., 288 Babcock commercial layers were subjected to a newly developed molting schedule. The fowls had completed their 1st production cycle at 76 weeks of age. The layers were given full feed and 24.5 h light during a premolt period of 3 days, along with treatment for helminths and vaccination for infectious bronchitis and Newcastle disease, and antibiotics during that period. For molting the photoperiod was reduced to 6 h per day for 7 weeks and the birds were subjected to fasting for 1 week accompanied with water deprivation for 3 days. This resulted in body weight reduction by about 27.3% with 1.04% mortality during the 1st week. The average hen-day egg production for the 42-week period was >71% with 89% peak production. The number of eggs laid per hen housed was 207.49 with a marked improvement in egg weight, averaging 63 g.

Descriptors: molting, performance, molt, induction, egg production, tropics


Akram M; Mushtaq-Ul-Hassan M; Farid S; Dar B; Raza NM; Khanum S (2001). Post-moult body weight and production performance of commercial layers induced to moult under various nutritional regimes. Acta Veterinaria (Beograd) 51(2/3 ): 163-170.

Department of Poultry Husbandry, University of Agriculture, Faisalabad, Pakistan.

            NAL Call Number: 41.8 V6447

The experiment was carried out on 288 commercial (White Leghorn) laying hens available at the age of 71 weeks. Birds were randomly divided into 18 experimental units comprising of 16 birds each. These experimental units were randomly allotted to 6 treatment groups designated as A, B, C, D, E, and F with 3 replications each. All groups were given a pre-moult treatment of vaccination and medication prior to subjecting them to the moulting schedule. Group A was maintained as a control. During the post-moult period, each bird was offered 110 g/day layer mash. Post-moult hen-day production (%), egg mass and feed efficiency (per kg egg mass basis) varied significantly between moulted and non-moulted birds. Less body weight was gained by the birds which were served with restricted feed (1.71 plus or minus 0.11) and corn (1.74 plus or minus 0.15) during the molt. The highest hen-day production (%) (82.87 plus or minus 6.89) and greatest feed efficiency (either per dozen eggs; 1.52 plus or minus 0.13 or per kg egg mass; 2.02 plus or minus 0.22) were noted in the birds which were fed with corn during the moult. Maximum egg weight (65.38 plus or minus 6.18) and feed consumption (743.24 plus or minus 30.50) were recorded in the birds offered with ration No. 3 during the moult.

Descriptors: body weight, egg mass, egg production, eggs, feed conversion, feed intake, feeding, hens, maize, moult, moulting, poultry

            Copyright© 2002, CAB International


Bai Y; Sunde ML; Cook ME (1994). Egg production of laying hens before and after force-molting is not correlated. The Journal of Applied Poultry Research 3(2): 127-132.

University of Wisconsin, Madison, WI.

NAL Call Number: SF481.J68

Descriptors: hens, laying performance, molting, fasting, restricted feeding, refeeding, duration, oats, hen feeding, selection criteria


Baker M; Brake J (1981). Relationship of body weight loss during a forced molt of commercial layers to optimum postmolt performance. Highlights of agricultural research - Alabama, Agricultural Experiment Station 28(2): 16.

NAL Call Number: 100 AL1H


Baker M; Brake J; McDaniel GR (1983). The relationship between body weight loss during an induced molt and postmolt egg production, egg weight, and shell quality in caged layers. Poultry Science 62(3): 409-413.

            NAL Call Number: 47.8 Am33P

Two trials were conducted to determine the relationship between percent body weight loss (% BWL) during an induced molt and postmolt performance. The molt was induced by fasting and photoperiod manipulation. Four groups with 24, 27, 31, or 35% BWL (Trial 1) or 20, 25, 30, or 35% BWL (Trial 2) were utilized in each trial. Performance was evaluated on the basis of 24 weeks of egg production and determinations of egg weight (EW), specific gravity (SG), and shell weight (SW) conducted during Weeks 8 (Trial 2 only), 18, and 24 following the removal of feed. The 27 and 31% BWL groups of Trial 1 and the 30 and 35% BWL groups of Trial 2 produced significantly more eggs per hen housed than the remaining treatments in their respective trial. Differences in SG and SW at the end of the trial were most pronounced in Trial 1 where the 27 and 21% BWL groups exhibited significantly greater SG and SW at Week 24 than did the 24 or 35% BWL groups. No significant differences occurred for SG at Week 24 of Trial 2, but the 35% BWL group exhibited significantly improved SW when compared to the 25% BWL group with the remaining groups intermediate. The EW was greatest for the 31% BWL and least for the 35% BWL group at 24 weeks in Trial 1 but did not differ in Trial 2. It was concluded that a body weight loss of approximately 27 to 31% produced optimum postmolt performance.

Descriptors: *Body Weight; *Chickens--physiology--PH; *Oviposition; Egg Shell; Eggs; Housing, Animal


Baloch WA; Suzuki H; Onoue Y (2000). Effect of different fasting and feeding regimes on body weight and productive performance of layers after first induced molt. Pakistan Journal of Zoology 32(3): 275-277.

Department of Freshwater Biology and Fisheries, University of Sindh, Jamshoro, Pakistan

            NAL Call Number: QL1 P3

One hundred and eighty commercial (Babcock) hens, 108 weeks old, after the completion of the first production cycle were kept in 18 experimental units comprising ten birds each. The 18 experimental units were randomly assigned to 6 treatment groups comprising 3 starvation X 2 feeding regimes in a factorial arrangement with 3 replicates. Groups A, B and C were starved for five, ten and 15 days, respectively. Two feeding regimes, feeding daily (groups AD, BD and CD) and on alternate days (groups AE, BE and CE) were carried out for ten days following each starvation regime. The results showed that the group of birds starved for 15 days with alternate day feeding maintained relatively less mean weight (1.51 kg) leading to significantly higher weekly egg number (4.82), egg mass (290.30 g), hen-day production (68.88), and better feed efficiency in terms of feed intake per dozen eggs (1.98) and per kg egg mass (2.75). However, egg weight showed no significant differences in relation to starvation or feeding regime.

Descriptors: body weight, egg production, egg weight, feed conversion efficiency, feed intake, feeding, feeding frequency, fowl feeding, management, poultry, starvation


Bar A; Razaphkovsky V; Wax E; Malka Y (2001). Effect of age at molting on postmolting performance. Poultry Science 80(7): 874-878.

Institute of Animal Science, Agricultural Research Organization, the Volcani Center, Bet Dagan, Israel.

            NAL Call Number: 47.8 Am33P

Molt was induced at the 431, 501, or 571 d, in Lohmann (L) and Hy-Line W-77 (H) hens, by 8 or 14 d, respectively, of feed withdrawal followed by a rest period of 16 d. Induced molt resulted in increases in egg production, numbers of intact eggs, egg mass per housed or surviving hen, and shell quality and in decreases in egg breakage (not significant), mortality, and culling. Egg weight was only slightly affected by molt, and the EW of hens induced to molt at 431 or 501 d of age were slightly lower than those of the unmolted hens or of those induced to molt at 571 d. Both strains reacted similarly to molt, although the L hens responded better, and expressed their responses more intensively when induced to molt earlier (431 d). This finding suggests that although different breeds have some effects of molt in common, molt protocols should be finely tuned for each breed. Total intact egg production and egg mass of the molted hens became higher than those of the unmolted hens at 650 to 728 d, which suggests that no benefit would be achieved by rearing molted hens for less than 700 to 730 d.

Descriptors: hens, molting, age, performance, age differences, feed rations, food restriction, egg production, fecundity, egg shell quality, mortality, culling, egg weight, egg mass


Bell D; Kuney D (1984). A comparison of force molting methods. IV. Progress in Poultry “Through Research.” June (27): 6 p.

University of California: Cooperative Extension, University of California.

NAL Call Number: SF487.8.C2P76

Descriptors: hens, molting, strain differences


Bell D; Kuney D (1979). A comparison of force molting methods. II. Progress in Poultry “Through Research.” Feb (15): 11 p.

University of California : Cooperative Extension, University of California.

NAL Call Number: SF487.8.C2P76

Descriptors: hens, molting, laying performance, diet


Bell D; Swanson M; Kuney D (1980). A comparison of force molting methods. III Progress in Poultry “Through Research.” May (21): 6 p.

University of California: Cooperative Extension, University of California.

NAL Call Number: SF487.8.C2P76

Descriptors: hens, molting, laying performance


Bell D (1991). Ten versus fourteen day fasting with and without molt feed. Poultry Adviser 24(12): 59-61.

University of California, Riverside, USA.

            NAL Call Number: SF481 P622

White Leghorns of 6 different strains were fed in 4, 28- to 40-week experiments of 10 or 14- days starvation followed by 18 days of diets containing cracked milo (sorghum) or fed immediately on mash diets. Body weight was decreased by 24.5 and 28.8% with 10 and 14 days starvation, respectively. 14 days starvation and 18 days of milo feeding gave the highest hen day egg production (60.9%), increased feed conversion efficiency, decreased mortality and gave favourable shell smoothness and thickness compared to the other treatments.


Bessarabov BF; Zhavoronkova LD; Kuznetsov VS; Gorbachev EP (1973).The use of artificial moulting in commercial poultry production. [Ispol'zovanie metoda iskusstvennoi lin'ki kur v promyshlennom ptitsevodstve.] Sbornik Nauchnykh Trudov. Moskovskaya Veterinarnaya Akademiya No. 71: 131-132.

In a flock of 6000 Katman-63 White Leghorns, aged 552 days, moulting was induced by 3 days of starvation and withholding of water, followed by gradual re-introduction of normal feeding, and restriction of light to 8 h/day, followed after 1 mth by an increase of ½ h light daily until the daily photoperiod reached 16 h. Laying had ceased entirely 5 days after the beginning of starvation, and started again on the 20th day. 50% egg production was reached on day 60. At 620 days of age, egg production percentage was 62 v 30 prior to the moult. Egg weight at 620 days of age in moulted birds was 11.2% greater than that of 16-mth-old, unmoulted birds.

Descriptors: moult, induction, egg production, egg weight

            Copyright© 2002, CAB International


Brake J; Thaxton P; Garlich J D; Sherwood DH (1979). Comparison of fortified ground corn and pullet grower feeding regimes during a forced molt on subsequent layer performance. Poultry Science 58(4): 785-790.

Poultry Science Dep., North Carolina State Univ., Raleigh, NC 27650, USA.

            NAL Call Number: 47.8 Am33P

The 160 Hyline W-36 and 3000 Shaver 288 Single-Comb White Leghorn hens were force-molted. Then for 18 days they received ground maize fortified with minerals and vitamins or growing feed for pullets. Performance was measured during the molt and for 5 or 6 periods of 28 days afterwards. Hens given the growing feed began to lay earlier than hens given maize, and reached peak production 4 weeks earlier. They produced more eggs of the same size and shell quality, with better feed utilization and mortality rate than the group given maize. 17 ref.

Descriptors: hen feeding, complete feeds


Buhr RJ; Cunningham DL (1994). Evaluation of molt induction to body weight loss of fifteen, twenty, or twenty-five percent by feed removal, daily limited, or alternate-day feeding of a molt feed. Poultry Science 73(10): 1499-1510.

Department of Poultry Science, University of Georgia, Athens, GA.

NAL Call Number: 47.8 Am33P

Postmolt egg production variables were compared among hens induced into molt by feed removal, by limited daily feeding of a low-density and low-energy molt feed at 22.8 g per hen, or by limited alternate-day feeding at 45.5 g per hen, until approximate body weight loss of 15, 20, and 25% was obtained. Hens were housed two per cage (25.4 x 45.7 cm) in a house of environmental design, and photoperiod was reduced to 8 h during the 28-d molt period. When target body weight loss was obtained, packed cell volume was determined and hens were maintained on 45.5 g/d of 1.2% calcium prelay feed through the 28-d molt period. Egg production and mortality were recorded daily; egg weight, egg specific gravity, body weight, and feed intake were recorded at 4-wk intervals postmolt. Packed cell volume of hens molted by feed removal (36.4%) was higher (P < .01) than that of alternate-day (34.1%) or daily limited (33.6%) hens. Hens that lost 25% of their body weight had higher packed cell volume (36.3%) than hens that had body weight loss of 20% (34.4%) or hens that lost 15% (33.4%). Postmolt mortality and egg production were not different (P > .05) as a result of molt induction method or percentage body weight loss. At the 4th wk postmolt, body weights were 50 and 57 g heavier for hens that had lost 15% body weight than those that lost 25 or 20%, respectively, and egg production was negatively linearly related to body weight loss. From the 8th to the 28th wk postmolt, within 4-wk periods, molt induction method or percentage body weight loss did not affect feed consumption (91.8 to 103.9 g), egg weight (66.0 to 66.2 g), egg specific gravity (1.0823 to 1.0831), or body weight (1,634 to 1,788 g).

Descriptors: hens, molting, weight losses, body weight, hematocrit, egg production, feed intake, fasting, mortality


Camiruaga LM (1977). El ave de postura. Pro y contra de la pelecha forzada [The laying hen. The pros and cons of forced molting]. Journal: Campesino 108(12): 26-33.

Universidad Catolica de Chile, Santiago

            NAL Call Number: 9.3 So12


Castanon F; Leeper RW; Parsons CM (1990). Evaluation of corn gluten feed in the diets of laying hens. Poultry Science 69(1): 90-97.

University of Illinois at Urbana-Champaign, Urbana, IL

NAL Call Number: 47.8 AM33P

The use of corn gluten feed (CGF) in the diets of laying hens and in induced molting programs was investigated through four experiments. The first two experiments evaluated the effects of CGF on egg production from 23 to 56 or from 32 to 65 wk of age. Graded levels of CGF from 0 to 25% were added to a corn-soybean meal, control diet (16.5% CP) in a nonisocaloric and an isocaloric manner. The ratio for dietary MEn:protein was held constant in some diets, but varied in others. The nonisocaloric inclusion of up to 25% CGF did not negatively affect egg production in either experiment. When 25% CGF was fed to the 32 wk old hens, egg weight was decreased. Egg weight was also decreased when 10% CGF or higher levels were fed to the younger hens. The nonisocaloric addition of CGF also increased feed intake and decreased feed efficiency (gram of egg per gram of feed) in most cases. Isocaloric inclusion of 15% CGF did not affect egg-production parameters, but 25% CGF negatively affected most parameters. When the ratio for MEn:protein of the CGF diets was equal to that of the control diet, 25% CGF negatively affected most parameters, 17.5% CGF decreased egg weight and feed efficiency, and 10% CGF increased egg production. Feed intake was increased at all of the CGF levels. Two additional experiments evaluated CGF in programs for induced molting. The molting procedure involved feed withdrawal for 10 days followed by feeding molt diets consisting of 99.75% corn, 99.75% CGF, 49.75% corn:50% CGF, or two grower-type diets for pullets (15% CP) containing 25% CGF or 18.5% wheat bran. The two grower-type diets for pullets yielded similar and significantly greater postmolt gains in body weight and early postmolt egg production (3 wk) than did the other diets. The corn:CGF diet also yielded greater postmolt weight gains and early postmolt egg production than the 100% corn or 100% CGF diets. Long-term postmolt egg production (30 or 37 wk) was not affected by the molt diets.

Descriptors: *Animal Feed; *Animal Nutrition; *Chickens--physiology--PH; *Gluten--administration and dosage--AD ; Chickens--growth and development--GD; Corn; Oviposition


Cave NAG (1983). Effect of duration of induced-molting period on broiler breeder hens. Poultry Science 62(7): 1398.

Agriculture Canada, Centre for Animal Research, Ottawa KLA 0C6, Ontario, Canada

            NAL Call Number: 47.8 Am33P


Christmas RB (1987). Short rests versus long molt of laying hens. Proceedings of the ... Florida Poultry Institute (46th): 42-52.

University of Florida, Chipley, FL

NAL Call Number: SF481.2.F56

Descriptors: hens, eggs, egg production, molt, rest, specific gravity, laying performance


Christmas RB (1986). Recent force resting procedures for laying hens. Poultry Adviser 19(11): 27-34.

Poultry Science Dep., Univ. Florida, Gainesville, FL, USA

             NAL Call Number: SF481 P622

Laying hens are force-rested one or more times during their productive life in order to improve egg-shell quality, egg production and cash flow. Force-resting includes starvation for 7 to 10 days with or without water for 1 day. Starvation is followed by feeding on a low-protein, low-calcium diet until egg production is resumed. Literature on force-resting of layers is reviewed.

Descriptors: egg shell quality; egg production, force resting


Christmas RB; Harms RH (1984). The subsequent performance of hens subjected to standard or short 4 day force rest methods. Poultry Science 63(SUPPL. 1): 79-80.

Dep. Poultry Sci., Univ. Fla., Gainesville, FL 32611.

            NAL Call Number: 47.8 Am33P


Christmas RB; Harms RH (1983). The performance of four strains of laying hens subjected to various postrest combinations of calcium and phosphorus after forced rest in winter or summer. Poultry Science 62(9): 1816-1822.

             NAL Call Number: 47.8 AM33P

Four strains of laying hens, including one brown egg strain, were force-rested in February at approximately 62 weeks of age. Hens from the same four strains, which were the same age, were also force-tested under similar conditions during August of the same year. In each of the two trials, a total of 2300 hens were housed at the rate of two per 25.4 x 45.7-cm cage. The resting procedure for both studies included feed withdrawal for 9 or 10 days followed by feeding a 8.6% protein diet for 25 days. Water was supplied at all times. After the 35-day resting period, the hens were assigned to four calcium and phosphorus combinations, which varied from the duplication of a first-year pullet phase feeding program to the feeding of a final phase type diet for the entire postrest production period. Nutrient level within each dietary system was adjusted periodically based on daily feed intake. Strain performance differences were observed in both seasons. Rate of return to production and postrest production rates were similar to the patterns observed within the respective strain's performance during the pullet year. This was noted in both studies. Relative strain production performance, however, when compared to the other strains, was not consistent between the two rest seasons. There was no difference in performance due to calcium and phosphorus treatment utilized in either postrest production season.

Descriptors: *Calcium Phosphates--administration and dosage--AD; *Calcium, Dietary --administration and dosage--AD; *Chickens--physiology--PH; *Oviposition ; Body Weight; Chickens--genetics--GE; Seasons

CAS Registry No.: 0 (Calcium, Dietary); 10103-46-5 (calcium phosphate)


Christmas RB; Harms RH (1983). The effect of protein level during force-rest recovery on the performance of winter or spring rested laying hens. Poultry Science 62(7): 1403.

University of Florida, Dept of Poultry Science, Gainesville, Florida 32611

            NAL Call Number: 47.8 AM33P


Christmas RB; Harms RH (1983). Performance of laying hens subjected to various nutritional systems after force-rest in the winter or summer. Poultry Science 62 (7): 1402.

University of Florida, Dept of Poultry Science, Gainesville, Florida 32611

            NAL Call Number: 47.8 AM33P


Christmas RB; Harms RH (1983). Subsequent post-rest performance of laying hens as affected by water restriction at 2 different times during the force rest period. Poultry Science 62(7): 1341.

University of Florida, Dept of Poultry Science, Gainesville, Florida 32611

            NAL Call Number: 47.8 AM33P


Christmas RB; Harms RH (1983). The postrest performance of laying hens subjected to early or late water restriction during the feed withdrawal period (Force-rest). Poultry Science 62(12): 2489-2491.

NAL Call Number: 47.8 AM33P


Christmas RB; Harms RH (1983). The performance of four strains of laying hens subjected to various postrest combinations of calcium and phosphorous after forced rest in winter or summer (Metabolism and nutrition). Poultry Science 62(9): 1816-1822.

NAL Call Number: 47.8 AM33P


Christmas RB; Harms RH (1982). The effect of various post molt nutritional systems on the performance of 4 strains of laying hens force molted in the winter or the summer. Poultry Science 61(7): 1438.

Univ. Florida, Dep. Poultry Sci., Gainesville, Florida

            NAL Call Number: 47.8 AM33P

Descriptors: protein, diet, feed withdrawal, egg production


Christmas RB; Harms RH; Junqueira OM (1985). Performance of Single Comb White Leghorn hens subjected to 4 or 10-day feed withdrawal force rest procedures. Poultry Science 64(12): 2321-2324.

NAL Call Number: 47.8 AM33P

Descriptors: hens, laying performance, molting, egg shell quality, rest, fasting


El-Beeli MYM; El-Zubeir EA (1991). Feeding whole-grain sorghum (Feteraitea) as a resting agent in egg-type breeder hens. Sudan Journal of Animal Production 4(2): 121-131.

Institute of Animal Production, University of Khartoum, Khartoum North, Sudan.

Use of whole-grain sorghum to induce moulting in egg-type breeder hens and whether forced moulting techniques would have beneficial effects on reproductive performance were studied. Hens in 5 groups were fed on a control diet of ground sorghum 600, wheat bran 160, sesame meal 50, groundnut meal 50, fish meal 50, oyster shell 80 and NaCl 5 g/kg, or that diet plus zinc oxide 25 or potassium iodide 6.58 g/kg, or the control diet devoid of oyster shell or made up entirely of whole-grain sorghum. During the first 28 days of the trial, all hens received the control diet, and then for 21 weeks they were fed on each of the 5 group-diets. With the high-Zn, high-iodine, low-calcium and whole-grain sorghum diets, the number of days it took the hens to achieve minimum egg production was 20, 17, 70 and 26 days, respectively, and average daily feed intake was 59.1, 84.4, 58.9 and 90.0 g. During the 2nd phase of laying from 73 to 97 weeks old, percentage hen-day egg yield was 48.2, 38.5, 41.0, 47.8 and 38.4, in the 5-group order. Percentage mortality was 8.3, 15.9, 8.0, 8.0 and 9.4. There were no significant differences between groups in mean egg weight or Haugh units. Egg shell thickness was 0.048, 0.054, 0.052, 0.0511 and 0.053 cm; percentage egg fertility, 66.5, 74.3, 60.1, 56.9 and 81.6; and percentage hatchability, 71.7, 70.8, 60.3, 63.9 and 61.5. It was concluded that whole-grain sorghum can be used successfully to induce molting in egg-type breeder hens.

Descriptors: hen feeding, moulting, egg fertility, egg hatchability, zinc, iodine, supplements, hens

            Copyright© 2002, CAB International


Embleton H; Hinds H B (1941). Poultry feeding experiments / by H. Embleton; Molting and housing experiments / by H.B. Hinds. Bulletin / University of Arizona, College of Agriculture, Agricultural Experiment Station no. 177: 331-365.

University of Arizona Agricultural Experiment Station Tucson, Ariz. : University of Arizona NAL Call Number: 100 Ar4 no.177

Descriptors: poultry, Arizona, feeding and feeds, feed utilization efficiency, housing, molting


Emeash HH; Attia MZ (1998). Performance and behavioural characters of layers as influenced by forced molt. Proceedings of the Fifth conference of the Egyptian Veterinary Poultry Association, p. 217-233

Cairo Univ., Beni-Suef (Egypt). Faculty of Veterinary Medicine)

Descriptors in English: layer chickens, forced molting, laying performance, blood composition, age, cages, egg production, behaviour , animal housing, animal husbandry methods, animal performance, animal production, birds, blood, chickens, domestic animals, galliformes, livestock, poultry, production


Escalante Cruz RE; Herrera Crespo JA; Lozano Torres MN; Oliveros Carballosa OO (1993). Evaluation of two systems of induced molting in commercial White Leghorn laying hens. [Evaluacion de dos sistemas de muda forzada en la ponedora comercial Leghorn blanca.] Revista de Produccion Animal, Cuba 7(3): 105-108.

Combinado Avicola Nacional, Camaguey, Cuba.

32,512 hens were deprived of water for 3 days and of food for 7 days (group 1), and 70,500 hens were deprived of water for 3 days and of food for 10 days (group 2). After treatment, the egg production was 50.6 and 50.3% respectively for hens in the 2 groups, egg production per hen averaged 157.2 and 153.6 respectively, food intake per kg eggs 2.32 and 2.44 kg, and the percentage of normal eggs was 96.1 and 96.0. All differences between groups were non-significant, but the 10-day fast produced a significant saving in feeding costs compared with the 7-day fast. Mortality was <2% in both groups.

Descriptors: hens, profitability, restricted feeding, molting, induction, egg production, feed conversion efficiency, mortality, tropics, laying performance

            Copyright© 2002, CAB International


Farran MT; Dakessian PB; Darwish AH; Uwayjan MG; Dbouk HK; Sleiman FT; Ashkarian VM (2001). Performance of broilers and production and egg quality parameters of laying hens fed 60% raw or treated common vetch (Vicia sativa) seeds. Poultry Science 80(2): 203-208.

NAL Call Number: 47.8 Am33P

Two experiments were conducted to study the effect of feeding 60% untreated (U) or coarsely ground treated vetch (V) seeds on performance of broilers and laying hens. In Experiment 1, the V seeds were soaked in 1% NaHCO3 (1:10) or in 1% acetic acid (1:5) at room temperature for 24 h (RTAA). Birds on the NaHCO3-treated V diet had 100% mortality rate but had significantly longer survival time than those on UV (14.9 vs 5.1 d). Birds on RTAA-V survived and had similar BW and feed conversion but greater kidney size than those of the controls at 7 wk of age (P < 0.05). In Experiment 2, control, UV, V soaked in water at 40 C (40WV), RTAA-V, and V soaked in acetic acid at 40 C (40AAV) diets were fed to laying hens for 84 d. The ground seeds in RTAA-V and 40AAV were soaked in acetic acid (1:10) at room temperature or at 40 C, respectively, for 24 h. For 40WV, the seeds were soaked in water (1:10) at 40 C for 72 h with a water change every 12 h. The UV-fed hens ceased egg production within 14 d and had the highest BW loss and the lowest feed intake among all treatments (P < 0.05). The 40WV and 40AAV significantly improved these criteria. Moreover, the RTAA-V resulted in performance comparable to that of the controls. Eggs produced by hens on treated V diets had similar weight but higher Haugh unit score (11 points), thinner shell, and lower yolk color score than those of the controls (P < 0.05). Results indicated that RTAA-V at 60% dietary level was not detrimental to broilers and laying hens.

Descriptors: broilers, hens, vetch, vicia sativa, seeds, chemical treatment, sodium bicarbonate, acetic acid, detoxification, poisoning, mortality, liveweight gain, feeds, feed conversion, dressing percentage, feed intake, molting, laying performance, egg weight, egg quality, egg shell thickness


Fedorchenko NG; Bololepov VI (1978). Artificial induction of moulting in hens and its use in reducing mortality from disease. [Kotsenke metodov iskusstvennoi lin'ki kur.] Veterinariya, Moscow, USSR (No. 10): 86-87.

Laboratoriya po Boleznei Molodnyaka Zhivotnykh, Ministerstvo Sel'skogo Khozyaistva, Moscow, USSR.

During artificial moult induction by restricted drinking, feeding and lighting regimes (conventional) the main cause of losses was leukosis (40%). With administration of an anabolic, losses were due mainly to diseases of the egg-forming organs (71.5%). With I/m injection of 1-2.5% oily solution of progesterone, losses occurred from leukosis, diseases of the egg-forming organs, hepatitis and visceral gout. Total losses by the three methods were (respectively) 1.7% of 596 birds, 2.25% of 301, and 1.4% of 294 birds. Other losses were due to cannibalism, pneumonia and colibacteriosis (first method) and enteritis (second method). The first method may be included in control measures for leukosis and other diseases in a breeding flock.

Descriptors: progesterone, anabolics, moulting, hens, poultry, moult, induction, mortality, poultry diseases

            Copyright© 2002, CAB International


Fratila SO; Nedelescu P (1981).Technique of forced molting in layer hens. [Contributii la tehnica napirlirii fortate a gainilor ouatoare.] Revista de Cresterea Animalelor 31(10): 19-23.

            NAL Call Number: 49 P943

Descriptors: hens, feathers, molting


Garcia EA; Mendes AA; Curi PR; Pinto MCL; Silva ABP da; Poiatti ML (1996). An evaluation of performance and egg quality of semi-heavy laying hens submitted to induced molt and fed low energy rations during different periods. [Parametros productivos e qualidade dos ovos de poedeiras semipesadas, alimentadas com racao de baixa densidade por diferentes periodos durante a muda forcada.] Veterinaria e Zootecnia 8: 75-84.

Departamento de Producao e Exploracao Animal, Faculdade de Medicina Veterinaria e Zootecnia, UNESP, 18618-000, Botucatu, SP, Brazil.

            NAL Call Number: SF604 V466

Descriptors: fowl feeding, egg production, performance, egg quality, hens, molting, energy deprivation, feeds, poultry


Garlich JD; Anderson KE; Brake J (1995). Molt induction by fasting: Effects of vitamin and electrolyte supplementation in the drinking water. Poultry Science 74(Suppl. 1): 190.

Dep. Poultry Science., N.C. State Univ., Raleigh, North Carolina

            NAL Call Number: 47.8 AM33P

Descriptors: chickens, hens, erythrocyte biochemistry


Garlich JD; Parkhurst CR (1982). Increased egg production by calcium supplementation during the initial fasting period of a forced molt (Laying hens). Poultry Science 61(5): 955-961.

NAL Call Number: 47.8 AM33P


Gerry RW (1979). The effect of forced molting (resting) on the performance of chickens laying brown eggs. Bulletin, Life Sciences and Agriculture Experiment Station, University of Maine May, Bulletin #755, 19 pp.

            NAL Call Number: 100-M28S-1

The results of a series of experiments designed to study the effects of periodic forced molting (by withdrawal of feed and/or water and manipulation of the lighting pattern) on the performance of medium-weight hens, (including breeders) laying brown eggs are reported. The study involved 2 types of birds, 2 experiments of 2 trials each, 2 laying years/trial, 2 types of housing (floors and cages) and several replicates of each treatment in each trial. All of the molting techniques reported caused the birds to cease egg production rapidly and did not cause excessive feather loss. The speed at which birds returned to production depended on the treatment received after the molt, but there appeared to be no advantage to prolonging the rest period. Egg production and feed efficiency over 2 years were not consistently improved although some improvement in egg production was usually observed following the molt. This varied from 10% among birds molted after 12 months of lay to no improvement among birds which had been subjected to a third molt after 18 months of lay. Greater mortality occurred during the first year of the 2-year trials and mortality tended to be less among birds which were molted more often. Treatment had little or no effect on egg weights but improved shell thickness in the second experiment. Interior egg quality, measured in Haugh units, improved after nearly every molt. The performance of force-molted breeding hens was similar and fertility and hatchability after recovery from the molt were similar to those from control hens.

Descriptors: egg production, forced molting


Gulyamov KKH; Komilov DK; Chugunkin DN; Akhmadov T (1977). Productivity, respiratory gas exchange and heat production in hens force-moulted by different regimes of starvation and water availability in a hot climate. [Produktivnost' I gazoenergeticheskii obmen u kur-nesushek, podvergnutykh lin-ke pri razlichnom rezhime golodaniya I dostupa k vode v usloviyakh zharkogo klimata.] Zhivotnovodstva 9: 139-148.

Tematicheskii Sbornik Nauchnykh Trudov. Tadzhikskii Nauchno-Issledovatel' skii Institut

            NAL Call Number: 49 Z6

In the experiment, groups 1-4, each of 1840 line 18 Katman crossbred fowls weighing, on average, 1272-1548 g before the experiment, were force-moulted by withdrawing food for 5, 8, 10 and 12 days resp., after which ad lib. feeding was progressively reintroduced over a 6-day period. Two subgroups of each group were, resp., (a) deprived of water for 3 days at the start of the experiment, and (b) given water ad lib. Egg production traits were recorded for 212 days after starvation. For the 8 subgroups resp. (i.e. 1a, 1b, 2a, 2b, etc.), egg weight averaged 60.1, 60.1, 60.5, 59.5, 59.8, 60.2, 60.9 and 59.9 g v 58.6 for all hens before the forced molt, shape index 1.38, 1.38, 1.40, 1.38, 1.38, 1.38, 1.40 and 1.38 v 1.36, egg sp. gr. 1.081, 1.078, 1.081, 1.081, 1.079, 1.081, 1.079 and 1.082 v 1.068, percentage of albumen in the egg 52.77, 52.33, 51.58, 52.43, 52.49, 53.01, 52.86 and 52.62 v 58.56, percentage of yolk 36.06, 36.33, 36.90, 37.06, 36.36, 36.72, 35.90 and 36.10 v 31.39, shell thickness 327, 329, 336, 341, 336, 334, 337 and 335 v 309 mu , albumen index 0.086, 0.086, 0.085, 0.086, 0.086, 0.086, 0.084 and 0.085 v 0.086, yolk index 0.431, 0.426, 0.428, 0.423, 0.426, 0.426, 0.422 and 0.429 v 0.418, percentage of hens culled 5.5, 5.7, 5.9, 5.6, 5.3, 5.1, 5.4 and 5.7 v 2.3, number of eggs laid during the experiment 84.08, 87.34, 87.80, 91.27, 83.61, 83.52, 89.82 and 97.27, and weight of food consumed/kg eggs laid 4.14, 3.96, 3.90, 3.76, 4.19, 4.01, 3.84 and 3.47 v 6.16 kg.

Descriptors: moult, induction, laying performance, nutrition, food restriction, water deprivation

            Copyright© 2002, CAB International


Gupta JJ; Singh KS (1987). Force molting by nutritional manipulation. Indian Journal of Poultry Science : Official Journal of the Indian Poultry Science Association. 22(3): 221-222.

ICAR Research Complex, Bishnupur, Shillong

NAL Call Number: SF481.I5

Descriptors: hen feeding, molting, egg production


Harms RH (1983). The relationship of molted primaries of commercial layers to first egg after molt. Poultry Science 62(6): 1123-1124.

NAL Call Number: 47.8 AM33P

The number of primary feathers molted was observed when hens were force molted in two separate experiments. The number of days required for the hens to return to production was directly related ® = .98, Experiment 2) to the number of primary feathers molted.

Descriptors: *Chickens--physiology--PH; *Oviposition ; Dietary Proteins--administration and dosage--AD; Feathers--physiology--PH


Harms RH (1983). Influence of protein level in the resting diet upon performance of force rested hens. Poultry Science 62(2): 273-276.

NAL Call Number: 47.8 AM33P


Hassanein EI; Awadallah SA; Ismail EY; Zahran KA (1985). Induction of forced molting in Isa-Brown layers by continuous food deprivation. Alexandria Journal of Veterinary Science 1(2): 93-102.

Zagazig Univ., Egypt, Faculty of Veterinary Medicine

Descriptors in English: chickens, weight, forced molting, laying performance, feed conversion efficiency, starvation, biological development, birds, digestibility, domestic animals, domesticated birds, feeding, galliformes, livestock, molting, nutritive value, performance, poultry, quality, useful animals


Hembree DJ; Adams AW; Craig JV (1980). Effects of force-molting by conventional and experimental light restriction methods on performance and agonistic behavior of hens. Poultry Science 59(2): 215-223.

Department of Animal Sciences and Industry, Kansas State University, Manhattan, Kansas

            NAL Call Number: 47.8 AM33P

White Leghorn females , aged 68 wk, were subjected to a stress period (no feed and 8-h light per day for 10 days) followed by a period when they were fed ground corn and given 8-h light per day for 18 days, or were given the same treatment except that the ground corn was supplemented with cystine, glycine, serine and threonine. White Leghorns not subjected to forced molting served as controls. During the molting period, the percentage hen-day production was 4.9 and 56.2 (P<0.05) for force-molted and control hens resp. The corresponding percentages during the first 28 days after molting were approx. 24 and 50 (P<0.05), and during 140 days after molting they were approx. 57 and 56.2 (P<0.05). In a 2nd experiment, White Leghorn females induced to molt by a regime of cracked corn and no light for 10 days produced heavier eggs (P<0.05) after molting than hens induced to molt by starvation and 8-h light per day.

Descriptors: molt, induction, laying performance, light, egg production, restriction, molt induction, force molting


Hembree DJ; Adams AW; Craig JV (1978). Effects of light restriction and amino acid supplementation on performance and agonistic behavior of forced-molted hens. Poultry Science 57(4): 1143-1144.

Dep. Animal Sciences and Industry, Kansas State Univ., Manhattan, KS 66506, USA.

            NAL Call Number: 47.8 AM33P

Descriptors: hen feeding, amino acids, egg production, lighting


Herrick RB; Ross E (1986). Intermittent and low-intensity lighting for force-molted laying hens. Research series - Hawaii Agricultural Experiment Station, Hitahr College of Tropical Agriculture and Human Resources. July, No. 049: 10 p.

Manoa : Hawaii Agricultural Experiment Station.

NAL Call Number: S539.5.R43

Descriptors: hens, molting, lighting, hen feeding, egg production, strain differences


Hill AT; Richards JF (1975). Effects of limited watering time on the performance of caged pullets and hens. Poultry Science 54(5): 1704-1706.

Research Station, Agriculture Canada, Agassiz, British Columbia, V0M 1A0, Canada.

            NAL Call Number: 47.8 AM33P

In 3 trials with a total of 640 pullets and 592 year-old hens, all Leghorns, some had water freely and others were offered it for 5 equally spaced periods daily, each of 25 min. For pullets, water restriction had no significant effect on egg production, feed conversion or mortality. For hens, it improved feed conversion significantly. In the second year of life, total number of eggs rose significantly when water was restricted immediately after the forced moult. Restriction had no effect on egg weight or the proportion of egg white solids or yolk solids.

Descriptors: hens, feed conversion efficiency, egg production, water restriction

            Copyright© 2002, CAB International


Hurwitz S; Bornstein S; Lev Y (1975). Some responses of laying hens to induced arrest of egg production. Poultry Science 54(2): 415-22.

            NAL Call Number: 47.8 AM33P

Arrest of egg production was induced by forced-molt (artificial light deprivation and feed deprivation for 10 days followed by 20 days of grain only) and by low-calcium regime in one experiment, and by Nicarbazin in another. Post-arrest production and shell quality significantly surpassed the control in the force-molt but not in the low-Ca treatment. At the onset of production, following the pause, egg weight and shell weight per unit of surface area rapidly increased up to the 9-10th egg. In the second trial, feed intake declined in about one week after the arrest in egg production to a non-layer level. During this week, body weight increased. However, despite the increase in feed intake after the onset of production, pre-arrest levels were not obtained even after 11 days, resulting in a loss of body weight. The separation of flock production into its components, rate of production of the layers, and the proportion of layers in the flock, is proposed.

Descriptors: *Chickens--physiology--PH; *Oviposition ; Animal Feed; Body Weight; Calcium, Dietary--administration and dosage--AD; Calcium, Dietary--metabolism--ME; Cereals; Chickens--metabolism--ME; Dietary Proteins--metabolism--ME; Egg Shell; Eggs; Fasting; Light; Nicarbazin--pharmacology--PD; Phosphates--administration and dosage--AD; Phosphates--metabolism--ME


Hurwitz S; Wax E; Nisenbaum Y; Plavnik I (1995). Responses of laying hens to forced molt procedures of variable length with or without light restriction. Poultry Science 74(11): 1745-1753.

Agricultural Research Organization, Bet Dagan, Israel.

NAL Call Number: 47.8 Am33P

The importance of the length of the rest period and of photoperiod as components of the forced molt procedure was evaluated in 650- and 560-d-old Lohman hens. The procedure included an 8-d feed withdrawal phase and rest periods varying from 0 to 35 d, during which the birds were fed for maintenance only. In the first trial, forced molt was applied with or without omission of artificial illumination. The rest period varied between 2 and 20 d. In the second trial, all treatments included omission of artificial illumination, and a variable rest period between 0 and 35 d. Egg production ceased, after 4 to 5 d of feed withdrawal and resumed 8 to 15 d after the end of the rest period, without any consistent response to its length. Forced molt stimulated egg production rate and diminished its age-dependent rate of decline, reduced the proportion of broken and shell-less eggs, and improved shell quality. Following wide oscillations proportional to the length of the rest period, egg weight stabilized at levels similar to that of the unmolted controls. Feed intake was stimulated by forced molt to levels exceeding those of the control hens. Body weight increased during the postmolt period to levels slightly exceeding those of unmolted controls. Results of one trial show that omission of artificial illumination was essential for the full expression of the molt responses. In the other trial, production rate and shell quality were improved and the percentage of broken eggs was reduced when the length of the rest period was increased. Maximal improvements appears to have been reached with rests periods of 14 to 21 d.

Descriptors: hens, molting, fasting, restricted feeding, duration, laying performance, egg shell quality, body weight, light regime, feed intake, unrestricted feeding, egg weight, egg shell defects, broken eggs


Hurwitz S; Wax E; Nisenbaum Y; Ben-Moshe M; Plavnik I (1998). The response of laying hens to induced molt as affected by strain and age. Poultry Science 77(1): 22-31.

Agricultural Research Organization, Bet Dagan, Israel.

NAL Call Number: 47.8 Am33P

Molt was induced in 502-d-old Lohmann, Hy-Line W-77, Yafa, and Yarkon strains of laying hens (Experiment 1), and at different ages during the 1st yr of production in the Lohmann strain (Experiment 2). The induced molt treatment included an 8-d feed withdrawal period followed by a 22-d rest period during which the birds received 60 or 70 g/d of a low-nutrient maintenance diet, in both experiments, respectively, and a reduced duration of daylight. In both experiments, induced molt resulted in an increase in postmolt egg production rate and a diminution of the rate of decline of production with age. The first eggs during the postmolt period were smaller than those of the unmolted birds but egg size increased rapidly to control levels. Egg breakage was markedly reduced by induced molt and its rate of increase with age was diminished. Postmolt feed intake was higher than that of the unmolted birds and body weights reached values higher than those of the controls. Those responses were not different among strains but the ranking among the strains in the molted group was similar to that of the unmolted controls, for all production traits. The postmolt rate of production approached that of first cycle peak and was not affected by treatment age. Shell quality as reflected by the percentage of breakage during the postmolt period was similar to that of the unmolted controls approximately 3 to 4 mo earlier

Descriptors: hens, molting, induction, strain differences, laying performance, egg shell quality, age differences, egg weight, body weight, egg shell, weight, egg shell defects, breakage, feed intake


Huyghebaert G; Fontaine G; Groote G de (1977). Vergelijkende studie van enkele kunstmatige ruimethoden bij W.L.-hennen [Comparative study of different treatments of forced molting in White Leghorn hens]. Landbouwtijdschrift 30(4): 957-977.

Rijkscentrum voor Landbouwkundig Onderzoek, Merelbeke, Belgium. Rijksstation voor Kleinveeteelt)

            NAL Call Number: 13 L233


Ingram DR; Mather FB (1988). White Leghorn production parameters as affected by body weight loss and length of rest period during a force molt. Nutrition Reports International 37(5): 901-908.

Dep. Poultry Science, Louisiana Agriculture Experiment Station, Louisiana State Univ. Agricultural Center, Baton Rouge, LA 70803, USA

            NAL Call Number: RC620 A1N8

In a 40-week 3 x 3 factorial design experiment 720 65-week-old Shaver 288A White Leghorn hens within 1.5 standard deviation of mean body weight were deprived of feed to achieve weight losses of 10 to 15, 20 to 25 or 30 to 35% and this weight maintained for 1, 3 or 5 weeks by feeding on ground maize every other day. After the treatment period, standard laying rations were given ad libitum. Egg production was recorded daily, egg weight and specific gravity were estimated on 3 days' eggs when egg production after molting reached 50% of premolting rate and once monthly afterwards. All treatments improved egg production over premolt birds, but overall postmolt hen-day egg production was not significantly different among treatments. Specific gravity was affected more by length of rest than weight loss.

Descriptors: egg production, molt


Jan ML (1982). Effects of force-molting on egg production of White Leghorn under subtropical environment. II. Effects of body weight and feed withdrawal time on egg production of force molted hens. T'ai-wan hsu mu shou I hsueh hui hui pao = The Taiwan Journal of Veterinary Medicine and Animal Husbandry 40 (August): 39-44.

NAL: 49 J822


Junqueira OM; Custodio RWS; Carvalho NP; Ariki J (1979). Effect of method of forced molting on laying hens. [O efeito de metodos de muda forcada no desempenho de galinhas reprodutoras.] Cientifica 7(Special No.): 119-122.

            NAL Call Number: SF604 C55

In 180 laying hens of different strains natural molting was compared with forced molting. Forced molting was induced at the start of natural molting to increase feather loss and completely stop laying. For forced molting there was total restriction of feed for 15 days and of water for 7, then 40 g feed was supplied daily for 4 days, subsequently 80 g daily for 11 days and finally 120 g. Egg weight was not affected significantly by method of molting, but egg production was increased after forced molting.

Descriptors: egg production, forced molting

            Copyright© 2002, CAB International


Kalayci UM (1990). Effects of breeding intensity and methods of molting preparations on the performance of light and medium weight laying hens in the second laying season [Auswirkungen der Aufzuchtintensitat und der Methodik der Mausereinleitung auf die Leistungen leichter und mittelschwerer Legehennen in der zweiten Legeperiode.] Thesis (doctoral)--Universitat Bonn, Germany, 137 p.

NAL Call Number: 105.8 B644 1990 [no.26]


Karunajeewa H; Tham SH; Hofmann A; Harris P (1986). The effects of rice by-products, acidulated soapstock and sunflower seeds on the laying performance of induced moulted hens. Archiv fur Geflugelkunde 50(5): 193-197.

Animal Research Inst., Princes Highway, Werribee, Vic. 3030, Australia

            NAL Call Number: 47.8 AR2

From 72 to 92 weeks old a total of 576 induced-moulted White Leghorn hens were in 6 treatment groups. The control diet (B1) was based on wheat and meat-and-bone meal and had linoleic acid 0.69%. In diets B2, B3 and B4 some of the wheat and meat-and-bone meal was replaced by either acidulated soapstock (ASS) rice pollard (RP) or deoiled rice pollard (DRP) to increase the linoleic acid contents in these diets to 1.00, 1.21 and 0.82%, respectively. In diets B5 and B6 mixtures of DRP and ASS (B5) and DRP and sunflower seeds (B6) were used to increase the linoleic acid content to 1.13 and 1.14%. All 6 diets were formulated to be isonitrogenous and isoenergetic (11.63 MJ/kg). Methionine (0.26%) and lysine (0.69%) in diets were equalized by supplementation with synthetic methionine and L-lysine HCl. Calcium in the diets was equalized to 3.4% but phosphorus varied with the inclusion of RP and DRP. Diets were given in the mash form for 5 periods of 28 days each. Increasing the linoleic acid content from 0.69 to 1.21% had no significant effect on egg weight or other production characteristics (rate of lay, daily feed intake, feed intake/kg eggs, body weight at 92 weeks, mortality). Inclusion of 2.16% ASS containing rapeseed soapstock reduced the proportion of eggs >65 g, and the inclusion of 1.67% whole sunflower seeds reduced the Haugh units (albumen quality) of eggs. The fatty acid composition of egg yolk was affected by the composition of the dietary fats.

Descriptors: rice byproducts, hen feeding, soapstock, sunflower seeds, egg production, nutrition, poultry

            Copyright© 2002, CAB International


Kashiwagi S; Shirasaki K; Kaizuka T; Nakaso H; Iwase N; Yamao H; Takahashi Y; Matsuzaki M; Ikeda K; Okuyama M (1981). Effects of restricted feeding during the rearing period and of induced molting during the laying period on laying performance of hens. Japanese Poultry Science 18(2): 67-77.

Kagoshima Prefectural Poultry Experiment Station, Sendai-shi 895, Japan.

            NAL Call Number: 47.8 N57

Two experiments were carried out in each of 9 poultry research stations. In each station one group of chickens was fed to appetite as a control and the others were given a restricted amount of feed every other day so that feed intake from 4 to 18 weeks of age was calculated to be 60% of that for unrestricted controls. After 18 weeks of age, all of the chicks were fed to appetite. At 20 weeks of age, the hens of both groups were sub-divided into 4 sub-groups each. The hens of the first and second sub-group were force-molted at 80 and 92 weeks of age, respectively. The hens in the third and the last sub-group were force-molted at 56 and 68 weeks of age, respectively, and all the hens were again force-molted at 96 weeks of age. All hens were kept until 128 weeks of age. Restricted feeding delayed sexual maturity, but resulted in larger first egg than those from hens fed to appetite. Bodyweight and daily feed intake of hens of the restricted group were less than for those of the unrestricted hens throughout the laying period, while mean egg weight of the former was less than that of the latter. Egg production of unrestricted hens was lower than that of hens on the restricted feeding programme after peak production. Among the 4 sub-groups on the restricted feeding programme, average egg production was almost the same regardless of age at the start of molting. In contrast, with unrestricted hens average egg production of the sub-group forced to molt twice at 56 and 96 weeks of age was the highest. Over 128 weeks the feed intake/kg eggs was significantly less for restricted hens than for unrestricted hens. Among the 4 sub-groups on the restricted feeding programme, little difference was observed in feed intake/kg eggs. Among the sub-groups on full-feeding, the lower the age at first molting, the lower was the feed intake. Haugh units of eggs laid by restricted hens were higher than for unrestricted hens. Forced molting increased both thickness of egg shell and Haugh unit of the eggs, though the difference in Haugh units before and after the second forced molting was not significant. After forced molting, restricted hens recovered egg production more rapidly than did unrestricted hens.

Descriptors: feed intake, hens, egg production, molting, hatching season, laying performance, molt, induction, nutrition, food restriction, age at first egg, sexual maturity, molt induction

            Copyright© 2002, CAB International


Katrich NI (1982). The intensity of induced moult and its relationship with the physiological condition of hens before the application of stress. Trudy, Kubanskii Sel'skokhozyaistvennyi Institut No. 212(240): 47-51.

For hens which continued egg production after they had dropped 2-3 primary wing feathers (group 1), hens which did not start moulting and continued egg production (group 2), hens which were in an advanced stage of moult (3-5 wing primaries) and had stopped egg production (group 3), and hens which did not molt but stopped egg production (group 4), the rate of regrowth of wing primaries 50 days after molt induction was 69.6, 54.2, 70.0 and 58.9% resp. The differences of the 1st and 3rd groups from the 2nd and 4th were highly significant.

Descriptors: moult, egg production

            Copyright© 2002, CAB International


Keshavarz, K. (1995). Impact of feed withdrawal and dietary calcium level on force-rested hens. The Journal of Applied Poultry Research 4(3): 254-264.

Cornell University, Ithaca, NY.

NAL Call Number: SF481.J68

Descriptors: hens, laying performance, food deprivation, rest, duration, experimental diets, calcium, nutrient content, egg production, egg mass, egg shell quality, specific gravity, bone ash, body weight, force resting, recovery diets


Khan AG; Lad BK (1996). Consequences of induced rest feeding programme (IRFP) on dwarf layer. Indian Journal of Animal Sciences 66(2): 177-183.

Dep. Poultry Sci., Jawaharlal Nehru Krishi Vishva Vidyalaya, Jabalpur, Madhya Pradesh 482 004 India

            NAL Call Number: 41.8 IN22

Response of dwarf layers to variable induced rest feeding programme (IRFP) was studied. Seven days fasting followed by 2,4 and 6 weeks of 20 g feed/bird/day constituted T1, T2 and T3 treatments. Data for 68 to 102 weeks of age was analysed along with that of the control. IRFP initiated shedding of primary feathers but the secondaries remained intact. T3 hens remained smallest in body size post-IRFP but T1 and T2 remained similar in size as that of the control. Control group hens laid more number of eggs than all treatment groups during IRFP periods. Post-IRFP to a fixed 28-weeks T1, T2 and T3 hens laid more eggs than the control, but the superiority was lost when post-IRFP to 102 weeks production was analysed. For 68 to 102 weeks of age, IRFP egg losses were compensated by higher peak and persistency in treatments as compared with the control. T3 hens laid heaviest egg. Feed consumption was associated linearly with the duration of IRFP irrespective of treatments. T3 group hens consumed less feed accounting 17.56% saving for production of 1 egg. In terms of economics, feed savings during IRFP equally contributed as the egg laid in the net financial gain which ranged from Rs -4.65 to + Rs 40.46 bird for different treatments.

Descriptors: economics, feed consumption, diet, egg production

            Copyright© 2002, Biosis


Kharitonov MM (1973). Effect of an artificial moult on the productivity of laying hens and the hatchability of their eggs. [Vliyanie iskusstvennoi lin'ki kur-nesushek na ikh produktivnost' I inkubatsionnye kachestva yaits.] Volgogradskii Sel'skokhozyaistvennyi Institut 50: 68-71

Moulting was induced in 1850 birds by depriving them of light, water and food for 2 days, after which each of the 3 factors was restored gradually. Compared with control birds in which moulting was not induced, treated females on resuming lay produced eggs which were 1.6 g heavier and had shells 16.4% thicker. For treated and control females resp., hen-housed egg production was 64.2 and 58.5%, egg fertility 82.1 and 74.6%, hatchability of eggs set 78.3 and 75.5%, and chick weight at 30 days of age averaged 235 and 224 g.

Descriptors: moult, induction, laying performance

            Copyright© 2002, CAB International


Khashem Y (1989). The effect of interrupted light. Ptitsevodstvo (No. 6): 30-32.

            NAL Call Number: Z5074 P8R4

Data were obtained on the egg-type commercial cross Zarya-17 (63 hens plus 6 old and 6 young cocks per group). The experimental group was maintained under a light regime which corresponded to the photoperiod allowed to the controls during growth, and was 2-h light:4-h darkness:8h-light:10-h darkness during the egg laying period. The controls were allowed light decreasing from 231/2 h daily at the beginning of growth to 9 h at 17 wk of age, and then increasing to 14-h daily. Egg production in the 1st yr of lay averaged 261.2 and 260.8 in the 2 groups resp., the percentage of eggs suitable for incubation 80.8 and 79.9, and hatchability of eggs set 90.3 and 86.1%. At 74 wk of age, the moult was induced by withdrawal of food and water for 4 days. For eggs laid in the 2nd cycle, egg fertility was 95.3 and 90.7%, hatchability of fertile eggs 90.8 and 87.5%, and hatchability of eggs set 86.5 and 79.4%. Egg production in the 34 wk after the moult averaged 138.5 and 141.0 in the 2 groups.

Descriptors: light regime, egg production, egg fertility, egg hatchability

            Copyright© 2002, CAB International


King DF; Trollope GA (1934). Force-molting of hens and all-night lighting as factors in egg production. Circular: Agricultural Experiment Station of the Alabama Polytechnic Institute No. 64: 1-7.

Auburn : Agricultural Experiment Station of the Alabama Polytechnic

NAL Call Number: 100 AL1S (2) no.64


Knowlton FL (1936). Force-molting of white leghorn hens. Station circular: Agricultural Experiment Station, Oregon State Agricultural College 119: 1-8.

NAL Call Number: 100 Or3 no.119


Koelkebeck KW; Parsons CM; Douglas MW; Leeper RW; Jin S; Wang X; Zhang Y; Fernandez S (2001). Early postmolt performance of laying hens fed a low-protein corn molt diet supplemented with spent hen meal. Poultry Science 80(3): 353-357.

Department of Animal Sciences, University of Illinois at Urbana-Champaign, 61801, USA.

            NAL Call Number: 47.8 AM33P

We used a total of 504 commercial Single Comb White Leghorn hens (69 and 65 wk of age) in each of two experiments, and hens were induced to molt by feed withdrawal only. Feed withdrawal lasted for 12 and 11 d, and hens lost 26 and 25%, body weight in Experiments 1 and 2, respectively. All hens were then weighed, and seven replicate groups of 12 hens each were assigned to molt diet treatments. In Experiment 1, diets consisted of a corn basal diet (7.9% CP) or corn basal diet supplemented with 7.5 or 10% spent hen meal (SHM) each from two different sources. In Experiment 2, the corn basal diet or this diet supplemented with 5 or 10% SHM alone or 5% SHM plus Met, Lys, and Trp was evaluated. A molt diet of 16% CP corn-soybean meal was used as a positive control in both experiments. Molt diets were fed for 15 d in both experiments, at which time all hens were fed a 16% CP layer diet. Performance was measured for 8 wk following the beginning of feeding the layer diet. Feeding the low-protein corn molt diet supplemented with 5 to 10% SHM improved early postmolt egg production performance and body weight gain compared with hens fed the corn basal diet alone. The 7.5 and 10% SHM diets yielded early postmolt performance that was not significantly different (P > 0.05) from that of hens fed the high-protein (16% CP) diet. Supplementing the 5% SHM diet with amino acids generally did not significantly improve performance. The present study thus indicates that improved early postmolt performance may be achieved by supplementation of a low-protein corn molt diet with 5 to 10% SHM.

Descriptors: Chickens--physiology--PH; Dietary Proteins--administration and dosage--AD ; Food Deprivation; Molting; Reproduction ; Animal Feed


Koelkebeck KW; Parsons CM; Leeper RW; Moshtaghian J (1991). Effect of protein and methionine levels in molt diets on postmolt performance in laying hens. Poultry Science 70(10): 2063-2073.

Department of Animal Sciences, University of Illinois, 324 Mumford Hall, 1301 W. Gregory Drive, Urbana, Illinois 61801, USA.

            NAL Call Number: 47.8 AM33P

In 3 experiments, laying hens 70, 65 and 96 weeks old were induced to moult by fasting (feed only) until 26 to 28% body weight loss occurred. Moult diets containing 16, 13 or 10% crude protein (CP) without or with 0.15% methionine were then fed until egg production reached about 10%, at which time all hens received a 16% CP layer diet for 30 weeks in experiments 1 and 2 and for 4 weeks in experiment 3. In experiment 1 (summer), hens regained body weight more rapidly, returned to production faster, and had larger egg weights (weeks 1 to 4) when fed the 16 or 13%-CP molt diets than when fed the 10%-CP moult diet. Long-term egg production, egg yield (grams of egg per hen per day) (weeks 1 to 30), and feed efficiency (weeks 1 to 8) were greater for hens fed the 16 or 13%-CP molt diets compared with those fed the 10%-CP molt diet. Methionine supplementation had no effect on postmoult performance. In experiment 2 (winter), the only significant treatment effect was that methionine supplementation increased egg weight (weeks 1 to 30). Moult diet had no consistent effect on egg specific gravity during the last 4 weeks of the postmolt production period in experiments 1 or 2. The effects of the dietary treatments on early postmoult performance in experiment 3 (early autumn) were similar to those observed in experiment 1. Results indicate that protein content, but not methionine supplementation, in moult diets influenced postmoult performance of hens during the summer and early autumn experiments, but not in the winter experiments.

Descriptors: Egg production, protein intake, moulting, methionine, supplements

            Copyright© 2002, CAB International


Koelkebeck KW; Parsons CM; Leeper RW; Jin S; Douglas MW (1999). Early postmolt performance of laying hens fed a low-protein corn molt diet supplemented with corn gluten meal, feather meal, methionine, and lysine. Poultry Science 78(8): 1132-1137.

Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana 61801, USA.

            NAL Call Number: 47.8 AM33P

Commercial White Leghorn hens (65, 63, or 70 wk of age in Experiments 1, 2, and 3, respectively) were induced molted by feed withdrawal until approximately 28% body weight was lost. All hens were then weighed, and seven replicate groups of 12 hens each were fed molt diets. In Experiment 1, three diets consisted of a corn basal diet (7.9% CP) or this diet supplemented with corn gluten meal (CGM) and Lys or feather meal (FM), Met, and Lys. In Experiments 2 and 3, varying levels of FM and FM with Met and Lys were evaluated. A 16% CP corn-soybean meal diet was used as a positive control in all experiments. The molt diets were fed for 17, 15, and 17 d in Experiments 1, 2, and 3, respectively, and production performance was measured for 8 wk from the beginning of feeding the layer diet. In all experiments, hens fed the 16% CP corn-soybean meal molt diet returned to egg production and regained body weight at a faster rate than did hens fed any of the other diets. In Experiment 1, early egg production of hens fed the corn basal diet supplemented with CGM and Lys or supplementation with FM, Met, and Lys was greater (P < 0.05) than that of hens fed the basal diet alone. In Experiment 2, very early egg production (Week 1) and body weight gain were lower (P < 0.05) for hens fed the corn basal diet than for hens fed the basal supplemented with FM, Met, and Lys. The addition of 5.75 or 8.5% FM or 5.75% FM plus Met and Lys generally increased (P < 0.05) early egg production and postmolt body weight gain compared to the corn basal diet in Experiment 3. The present study thus indicated that improved early postmolt performance may be achieved by supplementation of a low-protein corn molt diet with various combinations of CGM, FM, Met, and Lys.

Descriptors: Chickens--physiology--PH; Dietary Proteins; Molting; Reproduction ; Animal Feed; Corn; Feathers; Lysine--administration and dosage--AD; Methionine--administration and dosage--AD; Weight Gain


Koelkebeck KW (1991). Molting programs for layers: effect of dietary protein and methionine and length of fast on post-molt performance. Poultry Adviser 24(12 ): 49-51.

University of Illinois, USA.

            NAL Call Number: SF481 P622

In experiments 1 and 2 during summer and winter, White Leghorn chickens 65 and 70 weeks old were fed on maize/soyabean diets containing 10, 13 or 16% protein with 0 or 15% methionine until production reached 10%. A 16% protein layer diet was then fed for 30 weeks. In experiment 3, Leghorn chickens, 65 weeks old were fed on maize/soyabean diets containing 10 or 16% protein or 10% protein plus 0.25% lysine, 0.16% arginine, 0.10% threonine and 0.15% methionine or starved for 4 days and then fed on a 16% protein diet. Controls were not moulted. All diets were fed until 14% production was reached and then 16% protein diets were fed for 30 weeks. Body weight gain and egg production data are given in a table. In the summer experiment post-moult egg production in weeks 1 to 10 was 60.2, 64.9 and 65.1 with diets containing 10, 13 and 16% protein, respectively. In weeks 1 to 20 and 1 to 30 egg production was significantly higher in hens fed on the 16% protein diet compared with hens on the 10% protein diet. Feed intake was higher and body weight gain to 3 weeks lower for hens fed on the 10% protein diet compared with the hens on the 13 and 16% protein diets (100.4, 94.5 and 93.4 g/hen daily and 401, 431 and 441 g/hen, respectively). In the winter experiment, feed intake, body weight gain, egg production and egg weight were not different between hens fed on the different protein moult diets. In experiment 3, overall egg production was lowest in the non-molted controls compared with hens fed 16% protein diets at week 30 (65.7 vs. 74.6). Overall egg weights were higher for the non-moulted controls than for hens fed 10% protein diets, 64.2 vs.62.3 g/egg. Egg specific gravity at week 30 was lowest in the non-moult hens, 1.0736, and highest in hens fed on the 10% protein diet with amino acids, 1.0782 g/cm3. Egg shell quality was not affected by the short-term 4-day starvation. It was concluded that early and post-moult performance may be increased by protein moult diets containing 16 and 13% protein compared with 10% protein diets and that long-term egg production was not adversely affected by 4-day starvation periods used to induce moult. Methionine supplementation of moult diets had no benefit on post-moult egg production.

Descriptors: feed intake, liveweight gain, egg production, egg weight, protein intake, hens, egg quality, moulting, starvation, methionine, intake, soyabeans

            Copyright© 2002, CAB International


Koelkebeck KW; Parsons CM (1990). Nutritional aspects of molting programs. Poultry Adviser 23(2): 43-44.

University of Illinois at Urbana-Champaign, 1301 West Gregory Drive, Urbana, Illinois 61801, USA.

            NAL Call Number: SF481 P622

Experiments in summer and winter, each with 500 White Leghorn hens induced to moult by feed restriction, indicated that early post-moulting layer performance could be enhanced by increasing protein in the diet from 10 to 13 or 16%. However, these effects may be influenced by environmental temperature, since they were observed in the summer but not in the winter study. Long-term post-moulting performance was not substantially affected by using diets ranging in protein content from 10 to 16%, with or without added methionine.

Descriptors: moulting, restricted feeding, hens, protein intake

            Copyright© 2002, CAB International


Kummerfeld N; Luders H (1978). Effect of dark periods on the food and water intake of adult chickens. [Futterverzehr und Wasserkonsum von Huhnern bei Dunkelheit]. Deutsche Tierarztliche Wochenschrift 85(6): 212-216.

Tierarztliche Hochschule, Buntweg 17, D-3000 Hannover, German Federal Republic

            NAL Call Number: 41.8 D482

The influence of 12 hour light - dark cycles and 84 hours continuous darkness on the food and water intake were examined in 15 caged hens and 15 caged cocks. Once the light phase was over the chickens stopped their food and water intake during the first hour of the dark phase. Only in the cocks was an irregular, slight food and water intake ("nibbling") observed in the later period of darkness. Food and water intake of the cocks was maintained in the dark period corresponding to their physiological means in the intermittent 12 hour light period when the dark time had suddenly been prolonged to 84 hours. Hens subjected to 84 hours of darkness showed a reduction of food and water intake by 20% and a change in the food rhythm. No signs of molting were observed in the period of prolonged darkness.

Descriptors: animal behavior, lighting, feeding behavior, drinking, hens, feed intake, water intake


Lange K (1977). Forced moult in different strains of layers. [Die Zwangsmauser bei verschiedenen Legehennenherkunften]. Deutsche Geflugelwirtschaft und Schweineproduktion 29(41): 1096-1099.

Hessische Landesanstalt fur Leistungsprufungen in der Tierzucht, Neu-Ulrichstein, German Federal Republic

            NAL Call Number: SF481 D48

At 506 days of age, a forced moult was induced in 6 groups of white-egg and 3 groups of brown-egg layers (140 females /group). The white-egg strains involved were Shaver Starcross 288, Babcock B 305, Hisex White and HNL, and the brown-egg strains were Warren SSL and Babcock B 380. Food and light were withheld for 3 days, and were reintroduced gradually. Data on egg production in the 2nd laying period are tabulated. In the white-egg layers, egg production decreased to less than or equal to 1% within 6 days of beginning treatment v 9 days in the brown-egg groups. Egg production remained at less than or equal to 1% for 12 and 9 days resp. The time taken to regain 50% production was significantly shorter in the Hisex Whites and Babcock B 305s (43 and 45 days resp.) than in all other groups (54-60 days). In the HNLs, production after moulting averaged 83% of that in the pre-moult period v 72-76% for the other white-egg groups. Egg production averaged 158 eggs in the white-egg groups v 116 in the brown-egg groups, and hen-day egg production 56.6 v 41.4%. The unsatisfactory performance of the brown-egg layers was ascribed to the laying pause being too short. Overall, av. egg weight, the proportion graded 1-3, and egg-shell strength were improved over values in the pre-moult period.

Descriptors: moult, induction, egg production, strain differences

            Copyright© 2002, CAB International


Lee K; Holiday OR; Petty CE (1980). Effects of forced molt and rest on egg production, feed efficiency, and mortality of Single Comb White Leghorn hens. Poultry Science 59(7): 1566.

Dep. Agriculture, Univ. Arkansas, Pine Bluff, AR 71601, USA.

            NAL Call Number: 47.8 AM33P

Descriptors: egg production, molting, feed conversion efficiency, hens


Lien RJ; Roark LE (1993). Both feed and daylength restriction are important in recycling laying hens. Highlights of agricultural research - Alabama Agricultural Experiment Station 40(1): 14.

Auburn University, Ala.: The Station.

NAL Call Number: 100 AL1H

Descriptors: hens, restricted feeding, light, egg production, molting


Loedl J; Augustynski M; Wezyk S (1977). The use of induced moulting in hens kept for two seasons.[ Zastosowanie przymusowego przepierzania w dwusezonowym uzytkowaniu kur niosek.] Roczniki Naukowe Zootechniki 4(1): 249-257.

            NAL Call Number: SF1 R63 

Data are obtained over 2 yr on 455 Leghorn hens that were allowed to moult naturally and on 400 hens subjected to induced moult in the 13th mth of production using withdrawal of food for 7 days (some food was allowed on the 6th day), water for 4 days and light for 4 days, followed by light restriction to 8 h daily for 26 days. For the 2 groups resp., the performance in the 2nd egg production cycle, lasting 9 mth, was as follows: egg production percentage, 45.1 and 49.2; egg production, 123.2 and 134.3; egg weight, 65.7 and 65.6 g; egg mass, 8.09 and 8.81 kg; consumption of food/kg eggs, 5.45 and 3.85 kg; mortality, 11.6 and 12.2%; body weight at the end of experiment, 2184 and 2045 g.

Descriptors: moult, induction, laying performance

            Copyright© 2002, CAB International


Majun GK; Payne CG (1977). Autoclaved rice bran in layers' diets. British Poultry Science 18(2): 201-203.

Univ. Sydney, Poultry Husbandry Research Foundation, Camden, NSW 2570, Australia.

             NAL Call Number: 47.8 B77

In an experiment lasting 16 weeks 160 sixteen-month-old White Leghorn X Australorp hens, previously force-molted, were caged singly and fed on one of 5 diets with 17.0% crude protein. Control diet was based on wheat and soya bean meals; test diets had 30% rice bran, raw or autoclaved 20 min at 120 deg C, or 60% raw or autoclaved. For diets in that order, egg production/100 hen days was 73.5, 74.2, 75.6, 67.1 and 73.4 and egg mass was 48.4, 49.6, 49.1, 43.3 and 48.1 g/hen daily. Shell thickness and yolk colour were adversely affected by 60% raw rice bran.

Descriptors: hen feeding, rice bran

            Copyright© 2002, CAB International


Matsuzaki S; Takemoto Y; Murakami T (1994). Establishment of long-term utilizing technology of hen in windowless chicken house. Lighting method during and after forced resting period for intermittent lighting chicken. 2nd report. (Kumamoto Prefectural Agricultural Res. Center Livestock Laboratory S). Kumamotoken Nogyo Kenkyu Senta Chikusan Kenkyujo Shiken Seisekisho (Annual Report of the Kumamoto Prefectural Agricultural Research Center Animal Husbandry Research Insititute) 1994: 134-139.

Descriptors: laying hen, photic stimulation, egg-laying, chicken house, rearing management, lighting condition, feed efficiency, gravimetry, chicken egg, egg shell, energy saving, strain specificity


McKeen WD (1984). Feeding grape pomace to leghorn hens as an alternative to starvation to induce a molt. Poultry Science 63(Suppl.1): 148-149.

Univ. Calif., Agric. Cooperative Extension, 777 E. Rialto Ave., San Bernadino, California

            NAL Call Number: 47.8 AM33P

Descriptors: milo, metabolizable energy, protein, vitamin, mineral, weight loss


McKeen WD (1979). Hot weather and force molting (Hens). California Poultry Letter: University of California, Cooperative Extension Aug: p. 1-3.

NAL Call Number: SF481.C3


McKeen WD (1978). The use of grape pomace in a force molt feed. Progress in Poultry “Through Research.” Sept (13): 4 p.

University of California, San Bernardino County Calif.: Cooperative Extension, University of California.

NAL Call Number: SF487.8.C2P76

Descriptors: hen feeding, molting, grape pomace, egg production, laying performance, production costs, statistics


McKeen WD (1977). The use of a mixture of 50 percent grape pomace and 50 percent whole olive meal as a portion of a force molt ration. Progress in Poultry “Through Research.” July (8): 6 p.

San Bernardino County Calif. : Cooperative Extension, University of California.

NAL Call Number: SF487.8.C2P76

Descriptors: hens, feed requirements, grape pomace, olive pulp, laying performance, egg production, statistics


Mehta VS; Lahkotia RL; Singh B (1986). A study on forced resting and recycling of White Leghorn layers. Indian Journal of Animal Production and Management 2(3): 138-140.

Department of Livestock Production and Management, College of Veterinary and Animal Science, Sukhadia University, Bikaner 334 001, India

            NAL Call Number: SF55 I4I53

At the end of an 8-month laying period, a laying pause was induced in 255 White Leghorns by withdrawal of water and feed for 2-3 days, followed by restricted feeding for 4 wk. During the pause, hen-day egg production was <5% vs. 39% in 255 untreated layers (controls). After the resumption of ad lib. feeding, egg production returned to the level of the controls within 13 days. In the 7 months following the pause, hen-day egg production averaged 43.95% vs.33.2 in controls, and feed consumed per egg 216.2 g vs. 261.1. Over the total 16-month period, egg production in the 2 groups averaged 47.6 and 44.6% resp., and feed consumed per egg 199.1 and 222.1 g.

Descriptors: laying performance, molt, induction


Monteiro NM da C; Andrade AN de; Britto DPP de S; Guimaraes JF; Sinzato D; Costa FA (1971). A comparison between forced and natural moult in White Leghorn hens, caged at two different densities. [Comparacao entre muda forcada e muda natural em galinhas Leghorn Brancas alojadas em gaiolas, em duas densidades.] Pesquisa Agropecuaria Brasileira (Veterinaria) 6(4): 33-36.

Escritorio de Pesquisas e Experimentacao, Campo Grande, GB, ZC-26, Brazil

            NAL Call Number: S15 P42

Experiments carried out in Rio de Janeiro with a total of 3200 hens, caged singly or 2 to a cage, showed that there were no significant differences in egg production or quality characters between hens subjected to force moulting, achieved by providing no food or water for 48 h, followed by reduced rations for a further 12 days, and those moulting naturally. Egg production was highest during June-Aug., and it was higher in hens caged singly than in birds in a shared cage. Albumen density and Haugh unit scores were affected by season but not by housing density or type of moulting, whereas egg weight was affected by type of moulting, housing density and age of hen. It was concluded that there is a need for new methods of force moulting specially adapted for tropical conditions.

Descriptors: egg production, egg quality, egg weight, moult, induction, management, housing, cage density, seasons, age, hens

            Copyright© 2002, CAB International


Muhammad MUH; Muhammad A; Shah STH; Firdous R; Ahmad R (2000). Post-moult egg quality of commercial layers induced to moult under various fasting and feeding regimes. Acta Veterinaria (Beograd) 50(2/3): 131-136.

Department of Zoology, Government College, Faisalabad, Pakistan.

            NAL Call Number: 41.8 V6447

The effect of various starvation and feeding regimes during moulting on post-moult egg quality characteristics of commercial layers was studied. The experiment was carried out on 180 Babcock laying hens available at the age of 122 weeks during the second production cycle after the first moult induction. The birds were kept in single deck type cages comprising 18 experimental units of 10 birds each, that had previously been assigned to six treatment groups having three (5, 10, 15 days) starvation regimes x two (once-a-day and skip-a-day) feeding regimes in a factorial arrangement with three replications each. During the experimental period each bird was given 0.80 kg layer mash weekly. A total of 18 randomly selected eggs (one egg per experimental unit) taken every week were used for the study of egg quality (egg weight (g), shell thickness (mm), Haugh unit values and yolk index). The starvation and feeding regimes applied during the induced moult did not have any significant effect on post-moult egg weight, shell thickness, or yolk index. However, the differences in post-moult Haugh unit values in layers induced to moult under various starvation regimes and their interaction with feeding regimes were significant, whereas feeding regimes did not influence the mean Haugh unit values.

Descriptors: egg quality, starvation, feeding, egg weight, eggs, hens, poultry, moulting , management, egg shell thickness

            Copyright© 2002, CAB International


Mushtaq-Ul-Hassan M; Akram M; Sattar B; Raza NM; Dar B; Khanum S (2001). The influence of various rations during the molt on subsequent egg number and egg quality characteristic in commercial layers. Acta Veterinaria (Beograd) 51(2/3): 157-162.

Department of Zoology, Government College, Faisalabad, Pakistan.

            NAL Call Number: 41.8 V6447

A total of 288 laying hens, randomly divided into 18 experimental units with 16 birds each, were used in the study. Before the start of the molt induction all the birds were given a pre-molt treatment of vaccination and medication for one week to eliminate internal parasites and to protect against various diseases. Forty-eight birds (group A), which served as the control were continued on Ration No.3 (16.5% crude protein (C.P.) + 2850 Kcal/kg metabolizable energy (M.E.)). The remaining 240 birds were divided into 5 groups viz. B, C, D, E, and F, which were starved for 14 days for the induction of molting. Only water was given to these birds. After that, different rations were offered with different C.P. and M.E. contents for 14 days. Restricted feed (Ration No. 3) was given to group B on an alternate day basis (after 48 hours). Corn (9% C.P.), Ration No. 1, (20% C.P. + 2800 Kcal/kg M.E.), Ration No. 2 (15% C.P. + 2700 Kcal/kg M.E.) and Ration No. 3 were offered to the hens of groups C, D, E and F, respectively. All the groups were served with the same feed at the termination of the molting treatment. Post-molt egg number (5.57 plus or minus 0.52), egg weight (66.78 plus or minus 5.41 g) and shell thickness (0.39 plus or minus 0.04 mm) were significantly higher in birds which were subjected to the induced molt. Among the molted groups, the maximum number of eggs (5.80 plus or minus 0.48) were produced by the birds given corn during the molt, whereas the maximum egg weight (68.30 plus or minus 5.58) was noted in birds which were given Ration No.3. Shell thickness was greatest (0.41 plus or minus 0.04 mm) in birds which were treated with the restricted diet during the molt. Post-molt yolk index, Haugh units and meat spot values did not show any significant variations between the groups.

Descriptors: crude protein, egg characters, egg quality, egg weight, eggs, feeding, feeds, hens, maize, metabolizable energy, molt, molting, poultry, starvation


Mushtaq-Ul-Hassan M; Akram M; Shah STH; Firdous R; Ahmad R (2000). Post-molt egg quality of commercial layers induced to molt under various fasting and feeding regimes. Acta Veterinaria (Beograd) 50(2-3): 131-136.

Department of Zoology, Government College, Faisalabad, Pakistan

            NAL Call Number: 41.8 V6447

The effect of various starvation and feeding regimes during moulting on post-moult egg quality characteristics of commercial layers was studied. The experiment was carried out on 180 Babcock laying hens available at the age of 122 weeks during the second production cycle after the first moult induction. The birds were kept in single deck type cages comprising 18 experimental units of 10 birds each, that had previously been assigned to six treatment groups having three (5, 10, 15 days) starvation regimes X two (once-a-day and skip-a-day) feeding regimes in a factorial arrangement with three replications each. During the experimental period each bird was given 0.80 kg layer mash weekly. A total of 18 randomly selected eggs (one egg per experimental unit) taken every week were used for the study of egg quality (egg weight (g), shell thickness (mm), Haugh unit values and yolk index). The starvation and feeding regimes applied during the induced moult did not have any significant effect on post-moult egg weight, shell thickness, or yolk index. However, the differences in post-moult Haugh unit values in layers induced to moult under various starvation regimes and their interaction with feeding regimes were significant, whereas feeding regimes did not influence the mean Haugh unit values.

Descriptors: egg-quality, starvation, feeding, egg-weight, eggs, hens, poultry, moulting, management, egg shell thickness

Copyright© 2002, CAB International


Ohtsuka S (1986). Effects of limited lighting and restricted feeding on the resumption of laying after forced molting. Japanese Poultry Science 23(6): 334-343.

National Inst. Animal Industry, Ikenodai 2, Kukisaki, Inashiki, Ibaraki 305, Japan.

            NAL Call Number: 47.8 N57

Molt was induced in hens aged 70 wk by withdrawing water for 3 days and food for 10 days. Light was restricted to 6 h per day during forced molting, and on the 11th, 21st or 31st day after the beginning of molt induction it was increased by 1 h daily to 16 h. In the control group, 16-h light was maintained throughout the experimental period. Food was restricted to 45 g daily per bird for 10, 20 or 30 days after forced molting, and given ad lib. thereafter. In the controls, food was given ad lib. throughout. Egg laying ceased within 4-7 days after the treatments began. Egg laying resumed within 13-24 days after lighting was increased or ad lib. feeding began. When birds were given either of the treatments for 40 days, egg production was relatively high when it resumed after the molt

Descriptors: laying performance, molt, induction

            Copyright© 2002, CAB International


Ohtsuka S (1989). Effect of restriction of lighting and feed on resumption of laying after forced moulting. [Efectos de la restriccion de iluminacion y alimentacion en la reanudacion de la puesta despues de la muda forzada.] Revista Avicultura 33(1): 19-22.

National Institute of Animal Industry, Tsukuba Norindanchi, Ibaraki 305, Japan

            NAL Call Number: SF481 A9

The effect of restricted lighting (RL) or feed (RF) on resumption of laying after forced moulting induced by withdrawal of water and feed for 3 and 10 days, respectively, was studied in 2 experiments with 128 White Leghorn hens, 70 and 66 weeks old. In RL treatment lighting was restricted to 6 h daily during forced moulting increasing by 1 h daily, to 16 h on the 11th, 21st or 31st day after initiation of forced moulting. Hens were fed to appetite throughout. In RF treatment feed was restricted to 45 g daily for 10, 20 or 30 days after forced moulting and given to appetite thereafter. Lighting was 16 h, daily, throughout. Cessation of laying began 7 days after initiation of forced moulting and continued throughout RL and RF. Laying was resumed in a mean 18, 14, 22 and 15 days after 10, 20, 30 and 40 days RL and 18, 18, 15 and 14 days after 10, 20, 30 and 40 days RF treatment (including the forced moulting period) with unrestricted lighting and feeding. Both treatments had a similar effect on egg production. Production was relatively high after 40 days RL or RF.

Descriptors: egg production, restricted feeding, light regime, moult

            Copyright© 2002, CAB International


Ovejero RI (1992). Forced molting of commercial layer chickens. [La muda forzada de ponedoras comerciales]. Mundo Ganadero 3: 86-89.

Universidad Politecnica de Madrid, Spain

Descriptors in English: layer chickens, forced molting, animal husbandry methods, animal feeding, weight losses, laying performance, biological development, birds, chickens, domestic animals, domesticated birds, galliformes, livestock, losses, molting, performance, poultry


Palafox AL (1982). Effect of force molt in performance of laying hens raised in Hawaii. (Diets, feed composition, egg quality). Zootecnica International 10(October): 39-42.

NAL Call Number: SF600.Z6


Patel MB; McGinnis J (1981). Induced cessation of egg production forced molting by addition of guar meal to the diet. Poultry Science 60(7): 1710.

Dep. Animal Sci., Wash. State Univ., Pullman, Washington

            NAL Call Number: 47.8 AM33P


Petersen J; Horst P (1976). The effect of different treatments to induce a laying pause on body weight and laying performance. [Die Auswirkung unterschiedlicher Behandlungen zur Einleitung einer Legepause auf Korpergewichtsentwicklung und Leistungsgeschehen bei Legehennen.] Archiv fur Geflugelkunde 40(1): 13-22.

Institut fur Tierproduktion, Lentzallee 75, 1000 Berlin 33, German Federal Republic

            NAL Call Number: 47.8 AR2

In 900 HNL laying hybrids which were fed 2730 kcal metabolizable energy (ME) and 21% crude protein, moult was induced by 2 methods at 11, 15 or 18 mth of lay. Moult was induced (1) by the normal method (food, light and water deprivation for 4 days and maize restriction for 6 days), or (2) by a less severe method (similar restrictions for 3 and 2 days resp.). Level of nutrition had a significant effect on body weight before moult was induced. Body weight in all groups was significantly reduced by moult induction, but there was a lesser decrease using method 2 than method 1, and a slower recovery rate with method 2 after normal conditions were resumed. Egg laying was resumed 6 days earlier in hens given treatment 2 than in those given treatment 1, and performance in the first 100 days was similar in both groups. However, during the 6th-9th mth of the 2nd laying season, treatment-1 hens averaged 58.9 eggs, while treatment B hens laid considerably fewer (no figures given). Over the whole season, the more severely treated hens had significantly better egg production than the less severely treated hens. Egg weight was not affected by treatment, but shell stability was significantly better in hens given treatment 1 than in those given treatment 2.

Descriptors: moult, induction, body weight, laying performance, egg shell, age, animal nutrition, hens, egg production, moulting, poultry

            Copyright© 2002, CAB International


Rangel-Lugo M; Keshavarz K; McCormick CC (1986). Effect of dietary energy dilution and restriction on pre- and post-molt performance of laying hens. Proceedings - Cornell Nutrition Conference for Feed Manufacturers 1986: 57-63.

NAL Call Number: 389.79 C81

Descriptors: hens, diet, energy, restricted feeding, molt, performance ,


Rao SVR; Praharaj N K; Sunder GS; Raju MVLN; Reddy MR; Panda AK (2000). Requirement of lysine and total sulfur amino acid for force moulted WL layers. Archiv fur Geflugelkunde 64(5): 214-218.

Project Directorate on Poultry, Rajendranagar, Hyderabad, India

            NAL Call Number: 47.8 AR2

An experiment was conducted to determine the lysine and total sulphur amino acid (TSAA) requirements of chemically force moulted White Leghorn layers for a period of 24 weeks (81 to 104 weeks of age). Hens (72 weeks of age) were moulted by feeding excess zinc (15,000 ppm) for 10 days, followed by ground yellow maize for 25 days. Two basal diets were prepared with 16.0 and 12.5% CP (basal diet A and B, respectively) with the same metabolizable energy content. Basal diet A was fed to a group (5 replicates x 10 birds each) of moulted and a group of non-moulted layers. Basal diet B was supplemented with three levels of lysine (0.60, 0.70 and 0.80%) and three levels of TSAA (0.50, 0.60 and 0.70%) in a 3 x 3 factorial manner and each one was fed to a group of 50 moulted hens, divided into five replicates. Hen-housed egg production was higher (P<0.05) at 0.70% lysine and 0.60% TSAA (770 mg lysine and 680 mg TSAA intake per hen per day). The force moulted layer performance did not increase further at higher levels of lysine in the diet (0.80%). Feed intake, feed efficiency, albumin index, Haugh Unit score and shell thickness were also better at 0.70% lysine and 0.60% TSAA in the diet. Egg weight and shell percent were not influenced by dietary levels of lysine and TSAA in force moulted layers. The results of the present experiment indicated that force moulted WL layers require about 770 mg lysine and 680 mg TSAA of which 450 mg was methionine per hen per day.

Descriptors: hens, moulting, lysine, amino acids, sulfur amino acids, methionine, requirements, egg weight, egg production, egg quality, egg shell thickness

            Copyright© 2002, CAB International


Ravindran R; Narahari D (1991). Effect of different methods of force moulting on egg production, feed efficiency and mortality in White Leghorn hens. Journal of Veterinary and Animal Sciences 22 (1): 128-133.

Department of Poultry Science, Madras Veterinary College, Madras 7, India

            NAL Call Number: SF604 K42

120 White Leghorn hens, housed in individual cages, were fed ad lib. with 15% protein layer mash from 72 to 112 weeks of age (controls) or were subjected to 4 different force moulting treatments. There were no significant differences between hens in the 5 groups in egg production, daily feed intake, feed conversion efficiency and mortality.

Descriptors: restricted feeding, moulting, hens, molt, induction, egg production, feed conversion efficiency, mortality, tropics, laying performance, food consumption

            Copyright© 2002, CAB International


Rose SP; Campbell V (1986). Fatness of laying hens and induced molting regimens. British Poultry Science 27(3): 369-377.

NAL Call Number: 47.8 B77

Descriptors: hens, obesity, molting, thinness, restricted feeding, egg weight, egg shell quality, egg albumen haugh units, egg production


Rose SP; Campbell V (1985). Fatness of laying hens and induced moulting regimes. Research and Development Note, Scottish Agriculture Colleges (No. 28): 6 p.

Poultry Husbandry Division, North of Scotland College of Agriculture, Parkhead, Craibstone, Bucksburn, Aberdeen AB2 9SX, UK.

In 1100 Ross Brown laying fowls, aged 99 wk and which had been moulted at 60 wk, abdominal fatness was measured by calipers; the 324 birds with the lowest measurements were allocated to a "lean" group, and the 324 birds with the highest measurements to a "fat" group. The birds were then housed 3 to a cage. The birds were given 15 or 25 g whole wheat per day (skip-a-day feeding), and were molted for 2, 3 or 4 wk. After moulting, egg production was recorded for 22 wk after 50% production was reached. In the fat and lean groups resp., the number of days from the end of moult to 50% production averaged 23.95 and 21.37 (P<0.01), egg weight (0-11 wk) 67.93 and 67.38 g, egg production percentage (0-11 wk) 59.88 and 63.91 (P<0.05), and egg mass per bird per day (0-11 wk) 40.67 and 43.02 g (P<0.05). For 11-22 wk, only egg production percentage differed significantly between the 2 groups (44.35 and 48.10 resp.). The effects of moult length on laying performance were not significant, nor were most interactions involving fatness, moult length and feed level during moulting. The treatments did not affect egg quality or shell traits.

Descriptors: body composition, obesity, laying performance, moulting, body fat, egg production, moult

            Copyright© 2002, CAB International


Ruiz VJG; Gomez GLJ; Castro CE (1978). Induction of forced molt (in laying hens) by using steroid hormones. [Induccion de la muda forzada mediante el empleo de hormonas esteroides]. Revista - Facultad nacional de agronomia medellin.Universidad Nacional de Colombia. Facultad Nacional de Agronomia 31(1): 85-92.

Colombia, S.A., La Universidad.

NAL Call Number: 9.4 C717


Ruszler PL (1986). Comparison of certain methods for induced molting of layers. College Park : The Conference. Proceedings - Maryland Nutrition Conference for Feed Manufacturers p. 27-33.

NAL Call Number: 389.9 UN342

Descriptors: hens, diet, forcing, feathers (bird), losses


Ruszler PL; Minear LR (1997). Comparison of induced molts using periods of four vs ten days feed withdrawal. Poultry Science 76(Suppl. 1): 104.

Dep. Animal Poultry Sci., Virginia Tech., Blacksburg, Virginia 24061

            NAL Call Number: 47.8 AM33P

Descriptors: body weight loss, commercial flocks, four versus ten days feed withdrawal, induced molts comparison, light exposure


Sakaida T; Sugiyama M; Kinbara H; Akama E; Enya K (1976). Studies on feed restriction of layer. 1. Effect of feed restriction on performance of layers. Japanese Poultry Science 13(6): 235-242.

Enya Poultry Experimental Station, Esaki Gifu-shi, Gifu-ken, Japan.

            NAL Call Number: 47.8 N57

1. The study was with strain cross of White Leghorn (No. 1), two crossbreds of Rhode Island Red X White Leghorn (No. 2, 3) and strain cross of Rhode Island Red (No. 4), 162 of each. The layers were on full diet until 154 days of age, when they were divided into control and restricted group. Feed restriction was terminated at 519 days of age, and feed restriction rate was 90% of full diet of the control layers. Hens were subjected to force molting by starving for 7 days from 520 to 526 days of age, then for 365 days from 562 to 926 days were fed without restriction. Feed consumption of the restricted groups was 88.4% of the control during the experimental period. Hen-day egg production of restricted groups was 96.7% of the control group. The ratio of average egg weight and egg production per bird and day were 99.3% and 96.0% of the control groups. Feed conversion ratio was improved 0.24 by feed restriction. Bodyweight of the restricted groups was 88.6% of the control at 500 days of age. The restricted groups lost weight in the same ratio to feed intake. Egg production of both groups after force molting showed no effect of earlier feed restriction. (From summary.).

Descriptors: egg production, plane of nutrition


Samkharadze GS (1987). Optimum microclimatic conditions for hens during forced moult. Aktual'nye problemy zoogigieny v promyshlennom zhivotnovodstve I ptitsevodstve. (Current problems of hygiene in intensive livestock and poultry farming)., p.71-73

Moskovskaya Vet. Akad., Moscow, USSR.

The best conditions for keeping hens during artificially induced moult, in terms of feed consumption and subsequent hatchability, were provided by an environmental temperature of 21 deg C, relative humidity 76%, air exchange of 3.72 m3/hour per kg body weight, and an air flow rate of 0.24 m/s.

Descriptors: hens, poultry housing, moulting, microclimate

            Copyright© 2002, CAB International


Silva PCda; Zirlis AEF; Souza RNGde; Mercadante GdosS (1973). Inositol and methionine supplementation of caged hens during the second year of lay, with or without forced moult. [Supplementacao de inositol e metionina no segundo ciclo de postura, de galinhas em gaiolas, com e sem muda forcada.] Boletim de Industria Animal 30(1): 153-159.

Secao de Avicultura, Divisao de Zootecnia Diversificada, Sao Paulo, Brazil

            NAL Call Number: 49 R324

288 hens in 8 groups, which had been in lay for 14 mth, were given supplements of inositol, methionine, inositol + methionine or no supplements; half the birds in each group were subjected to forced moult and half were not. Forced moult had a significant, beneficial effect on egg production, Haugh unit score and egg shell thickness, but did not affect egg weight, food conversion or mortality.

Descriptors: moult, induction, laying performance, egg production, egg shell, thickness, egg quality

            Copyright© 2002, CAB International


Silveiro E (1987). Forced molting in layers. [Muda forzada de gallinas ponedoras]. ACPA ( Asociacion Cubana de Produccion Animal) no.3-4: 15-20. ISSN: 0138-6247

Instituto de Investigaciones Avicolas, Ciudad de La Habana, Cuba

            NAL Call Number: SF17 A862

Descriptors in English: layer chickens, molting, feathers, oviposition, laying performance, progesterone, livestock management, glucocorticoids , quality, eggs, adrenal cortex hormones, animal morphology, animal products, biological development, birds, chickens, corpus luteum hormones, corticoids , domestic animals, domesticated birds, galliformes, hormones, integument, livestock, performance, physiological functions, poultry, progestational hormones, reproduction, sex hormones, sexual reproduction, steroids


Sitnikov PA; Kni YuI; Shevtsova LI (1974). A study of the effect of artificial moulting on productivity of fowls.[Izuchenie vliyaniya iskusstvenno vyzvannoi lin'ki na produktivnost' kur.] Uchenye Zapiski Kazanskogo Gosudarstvennogo Veterinarnogo Instituta 116: 163-165, 279.

In 17-mth-old White Leghorns, moult was induced by shortening the daily photoperiod from 1 Oct. and by restriction of food and water over a 6-day period. The daily photoperiod was gradually restored to 14 h, starting 1 mth after the shortening of the photoperiod. A similar group of untreated birds served as controls. In the 2 groups resp., egg production in the 2nd yr of lay averaged 186.2 and 168.7, and survival rate of hens to the end of the 2nd yr was 73.4 and 57.5%. Hatchability was 8.1% higher for eggs of treated than for those of untreated birds.

Descriptors: moult, induction, laying performance, egg production, mortality, egg hatchability

            Copyright© 2002, CAB International


Sloan DR; Harms RH (1988). Recent research on resting of laying hens. Proceedings of the ... Florida Poultry Institute (47): 31-35.

Gainesville: Florida Agricultural Extension Service.

NAL Call Number: SF481.2.F56

Descriptors: hens, egg production, molting, feeding frequency, feathers, fasting, regulations


Soldevila M; Siberio V; Soto RD (1984). Recycling of hens by an induced rest period in laying. Original Title: Reciclaje de gallinas por medio de una pausa forzada en la postura. Memoria, Asociacion Latinoamericana de Produccion Animal 19: 35-46.

Estacion Experimental Agricola, Colegio de Ciencias Agricolas, Univ. Puerto Rico, Puerto Rico.

White Leghorn hens were studied during the 1st laying cycle, the induced rest-moult period, and the 2nd laying cycle. In a randomized block design 12 replicates of 8 hens were used in 4 treatments: T1, induced rest-moult when the laying rate decreased markedly below 50%; T2, induced rest-moult by restricting feed for 6 days and water on the 1st day after laying for 12 months, followed by giving maize for 18 days and then layer's feed; T3, induced rest-moult by adding zinc oxide, 25 mg/g, feed, for 4 days after 12 months of laying, then giving layer's feed; T4, 1st laying hens which reached 50% laying intensity when the other groups were beginning their 2nd laying cycle. In the 2nd laying cycle production was 82.3%, egg weight 1.02% (100% = standard egg 56.75 g), eggs/kg feed 7.2 and mortality 1.0% for T4 and all significantly different from the other groups, 62.1-64.5, 1.07-1.08, 5.5-5.7 and 10.4-11.5. Moult induced with ZnO and with restricted feed and water was 13 and 18 days, respectively.

Descriptors: egg production, moult


Starchikov N; Guzhva V; Dubovtseva M (1977). Forced moult in a parent flock of egg-producing fowls. [Prinuditel'naya lin'ka roditel'skogo stada yaichnykh kur]. Ptitsevodstvo 9: 24-26.

            NAL Call Number: Z5074 P8R4

Cross-288, line C hens (150/group) were subjected to induced moult by withdrawing food, water and light for 3 days. In the 1st group, both females and males were given the same treatment; in the 2nd group, the males were withdrawn before treatment and re-introduced later, and in the 3rd group, the males were withdrawn before treatment and replaced by young males after treatment. For the 3 groups resp., egg fertility over the 270 days after moulting averaged 82.3, 88.1 and 90.1%, and hatchability of egg set 89.7, 90.5 and 87.5%. The males were adversely affected by induced moult. Mortality in the 3 mth after induced moult was 15.3%; testis weight decreased from approx. 25 g before treatment to 1.2 g 1 mth after treatment, and returned to approx. 24 g by 120 days after treatment.

Descriptors: moult induction, reproduction, egg fertility, egg hatchability, mortality, testes, weight

            Copyright© 2002, CAB International


Stilborn HL; Waldroup PW (1990). An evaluation of low-energy feedstuffs in diets for laying hens. Animal Feed Science and Technology 27(4): 327-339.

P. W. Waldroup, Department of Animal Sciences, University of Arkansas, Fayetteville, AR 72701, USA

            NAL Call Number: SF95 A55

Rice bran (RB), lucerne meal (AM), wheat bran (WB) and maize gluten feed (MGF) were used in laying hen diets containing metabolizable energy (ME) 2500, 2600, 2700 or 2800 kcal/kg and compared with diets based on maize and soyabean meal (MS). Each diet was given to 8 groups of 5 individually caged hens, following a forced molt. Hen performance was influenced more by the source of low-energy feed than by dietary energy content. Hen-day production, egg weight, feed intake, feed per dozen eggs and weight gains for AM, RB and WB diets were similar to that for MS control diets with equivalent energy content. Egg production was similar for hens fed on a low ME intake of 2600 kcal/kg with these feeds and hens given higher energy diets. Increasing MGF intake reduced hen performance. It is concluded that performance on the lower ME diets is highly dependent on the type of feed byproduct used.

Descriptors: egg production, energy sources, lucerne meal, rice bran, wheat bran, maize gluten meal, maize, wheat

            Copyright© 2002, CAB International


Summers JD; Leeson S (1977). Sequential effects of restricted feeding and force-molting on laying hen performance. Poultry Science 56(2): 600-604.

Dep. Animal and Poultry Science, Univ. Guelph, Ont., Canada N/G 2W1.

            NAL Call Number: 47.8 AM33P

Laying hens were fed on diets with 15 or 17% crude protein, to appetite, restricted to 100 g/bird day or for 4 h each day (0800-1000 and 1430-1630 h). Dietary protein content had no significant effect on performance, but the full-fed birds ate more feed, produced a greater number of heavier eggs and gained more weight than restricted or time-limited birds. All birds were given a 15 or 17% crude protein diet to appetite after force-molting induced by removal of feed and water for a specified time. Pre-molt feeding had no effect during the molting period. During the post-molt laying cycle, birds that had previously been restricted or time-limited showed greater egg size and weight gain than birds fed freely during the first laying cycle. Dietary protein had no significant effect on production during the post-molt period. Egg shell deformation and Haugh unit measurements were not better after than before the molt.

Descriptors: egg production, feed restriction, forced molting


Sus H (1974). Results of experiments on moult induction under practical conditions. [Ergebnisse von Zwangsmauserversuchen in Praxisbetrieben.] Archiv fur Geflugelkunde 38(1): 9-13.

Abteilung Kleintierzucht, Universitat Hohenheim, Stuttgart, German Federal Republic

            NAL Call Number: 47.8 AR2

In the 1st experiment, with a flock of 500 HNLs, moult was induced after a 9-mth laying season by deprivation of water, food and light for 4 days. On days 5-10, half the flock were given 40 g oats/bird daily and the other half 40 g of an all-mash ration. In the 2nd experiment with 3 flocks (2HNL and 1 Hisex) totaling 4165 birds, the same methods of moult induction were used, but food deprivation was more severe. Moult was successfully induced in all flocks. After commencement of moult, it took 35 days for birds in the 1st experiment to reach a laying rate of 50% and 41-47 days for birds in the 2nd experiment. Trends in laying performance in the 2nd laying season were similar to those in the 1st, but peak production was not so high. Egg weight averaged about the same after moulting as before in both experiments. The percentage of cracked and broken egg shells was reduced from 9.98% before molting to 3.1% in the 2nd mth after moulting, and remained below 6% for at least 6 mth in the 1st experiment. Albumen height and yolk height showed marked improvement after moulting. No practical problems were encountered.

Descriptors: egg production, egg weight, egg shell defects, egg quality, moult, induction, laying performance, hens, moulting, animal husbandry, poultry

            Copyright© 2002, CAB International


Suwa K (1981). Effect of forced-rest during early laying period on post-rest performance (Poultry). The Niwatori-no-kenkyu = Poultry journal 56(12): 74-78.

Tokyo, Poultry Research Association.

NAL Call Number: 47.8 N64


Tatarchuk VV (1975). Effect of some stress factors on the production characters of hens of different reproductive activity. [Vliyanie nekotorykh stress-faktorov na produktivnye kachestva kur s raznoi polovoi aktivnost'yu.] Ptitsevodstva (No. 8): 94-96, 238.

Materialy Nauchnoi Konferentsii. Vsesoyuznyi Nauchno-Issledovatel'skii I Tekhnologicheskii Institut

            NAL Call Number: Z5074 P8R4

Groups of White Plymouth Rock hens of high, average and low reproductive performance (300 females /group) were used. Hens in the high-performance group had an av. production to 475 days of 205.7 eggs of 95.6% fertility and 93.2% hatchability, these values being 24, 14 and 10.3% resp. higher than in the low-performance group. When the females were subjected to forced moulting as a result of 10 days starvation, egg production in the 2nd laying period was 18.6 and 15.6% higher in the low-performance females than in the high-performance and av. ones resp. Following forced moulting hen viability was higher in the high- and av.-performance birds than in the low-performance ones (by 3.2 and 1.1% resp.).

Descriptors: laying performance, moult, induction

            Copyright© 2002, CAB International


Thomas WG; Bray DJ (1976). The response of broiler breeder hens to forced molting. Poultry Science 55(5): Abstract No. 2100.

            NAL Call Number: 47.8 AM33P

Descriptors: corn, oyster shell, light, mortality, egg, production, hatchability


Tonaka T (1980). A comparison of force molting methods (in laying hens). Circular letter - Hawaii University, Cooperative Extension Service October 1980, 89: 1-6.

NAL: SF481.H3


United States Office of Experiment Stations (1904). Experiment station work, XXIII losses in manure, apple pomace for cows, macaroni wheats, rations for laying hens, sterilizing greenhouse soils, early molting of hens, tomatoes under glass, evaporation from incubator eggs, protection of peach buds, the keeping quality of butter, dandelions in lawns, curing cheese in cold storage. Farmers' bulletin / United States Department of Agriculture no. 186: 32 p.

NAL Call Number: 1 Ag84F no.186


Verheyen G; Decuypere E (1988). Production results following forced molting by a mild and a severe starvation procedure in brown laying hens (Warren S.S.L.) [Produktieprestaties na toepassing van een diervriendelijke ruimethode en een strenge, konventionele vastenmethode bij bruine leghennen (Warren S.S.L]. Landbouwtijdschrift 41(2): Dutch edition 355-362; French edition 359-367.

Katholieke Univ. Leuven, Heverlee, Belgium, Lab. voor Fysiologie der Huisdieren [Lab. for Physiology of Domestic Animals)

            NAL Call Number: 13 L233

Descriptors in English: layer chickens, molting, starvation, light regimes, laying performance, agriculture, animal production, animals, biological rhythms, birds, chickens, domestic animals, domesticated birds, egg production, galliformes , light, nutrition, nutritional phenomena, physical states, poultry, production, radiations, time, timing, vertebrates


Verheyen G; Decuypere E (1983). Cessation of laying by induction in the hen. Effect of different methods on some production parameters and on the concentrations of thyroid hormones, prolactin, calcium, phosphorus, sodium and proteins in the blood serum (Force molting). [Arret de la ponte par induction chez la poule. Effet de differentes methodes sur certains parametres de production et sur les concentrations en hormones thyroidiennes, en prolactine, en Ca, P, Na et en proteines dans le serum sanguin.] Revue de l'agriculture 36(5): 1535-1559.

NAL Call Number: 13 R322


Yamagami Y (1990). Recent trend of increase in the number of hens under forced molting, and some problems in this relation. Yokei no Tomo 337: 28-38. ISSN: 0385-1648

Saitama Prefect. Poultry Exp. Stn.

Descriptors: rearing management, laying hen, molting, chicken egg, quality, egg-laying, economy, efficiency, egg shell, weight(gravity), freshness


Zhvikas EB (1976). Effect of different methods of forced moulting on reproductive characters of laying hens. [Vliyanie razlichnykh metodov prinuditel'noi lin'ki na vosproizvoditel'nye kachestva yaichnykh kur.] Ptitsevodstvu 4: 110-118, 142-143.

Sbornik Rabot. Pribaltiiskaya Zonal'naya Opytnaya Stantsiya po

            NAL Call Number: Z5074 P8R4

Nine groups each of 75 Leghorn layers were treated as follows at the end of the 1st laying season: (1) controls, maintained under 14 h light daily and with access to food and water; (2) light stress (light period increased to 24 h daily for 10 days, shortened abruptly to 8 h daily for 1 mth, and then lengthened to 14 h daily) but with access to food and water; (3) light stress and with access to water but starved for 6 days; (4), (5), and (6) as in (3) but starved for 8, 10 or 12 days resp.; (7) light stress, with access to food and water, and fed 0.7 g thyroid extract daily; (8) as in (7) but injected with 50 mg progesterone; (9) darkness, and withdrawal of water and food for 3 and 4 days resp. For the 9 treatments resp., egg production to the onset of forced moulting at 68 wk of age averaged 247, 247, 244, 238, 246, 238, 250, 250 and 246 v 216, 191, 222, 247, 230, 228, 213, 192 and 226 in the following 52 wk, group 4 producing significantly more and group 2 significantly less than the controls. Production to 43 wk after the onset of forced moulting was significantly better in groups 3, 4, 5, 6 and 9 (201, 230, 217, 216 and 212) and worse in group 2 (156) than in controls (178). Egg fertility 3 and 11 mth after forced moulting was generally higher than in birds aged 15-16 mth, but hatchability of eggs set was lower (69.4-87.1 and 64.9-73.8 v 88.8-95.1%). Corresponding values for hatchability in the control group were 87.7 and 80.5% v 92.9.

Descriptors: moult, induction, laying performance

            Copyright© 2002, CAB International


Zigic L; Srajber L; Masic B; Marinkovic V (1970). The effect of forced molting on the physical properties and inner quality of eggs layed by New Hampshire hens. Veterinaria (Sarajevo) 19(1): 66-71.

            NAL Call Number: 41.8 V6494

Descriptors: albumin, yolk, shell


Zimmermann N (1993). Effect of water additives during induced molt on postmolt performance of leghorn hens. Poultry Science 72(Suppl. 1): 64.

Dep. Anim. Sci., Wash. State Univ., Puyallup, Washington

            NAL Call Number: 47.8 AM33P


Zimmermann NG; Andrews DK (1990). Performance of leghorn hens induced to molt by limited feeding of diets varying in nutrient density. Poultry Science 69(11): 1883-1891.

Washington State University, Puyallup, WA

NAL Call Number: 47.8 AM33P

Descriptors: hens, hen feeding, nutrient density, restricted feeding, molt, laying performance, egg production


Zimmermann NG; Andrews DK; McGinnis J (1987). Comparison of several induced molting methods on subsequent performance of Single Comb White Leghorn hens. Poultry Science 66(3): 408-417.

Washington State University, Puyallup, WA

NAL Call Number: 47.8 AM33P

Descriptors: hens, molting, laying performance, fasting, restricted feeding, weight losses, guar meal, methionine, calcium


Zimmermann NG; Andrews DK; Mcginnis J (1985). Comparison of 12 induced-molt procedures. Poultry Science 64(Suppl.1): 204.

Department of Animal Science, Western Washington Research And Extension Center, Washington State University Puyallup, Washington.

            NAL Call Number: 47.8 AM33P

Descriptors: hen, guar meal, shell quality

Selected Websites

Induced Molting of Commercial Layers: North Carolina State University

The Keys to Successful Induced Molting of Leghorn-type Hens



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June 22, 2005