Items tagged "peer-reviewed journal article": 104

Fan Assessment Numeration System (FANS) design and calibration specifications

Fan Assessment Numeration System (FANS) design and calibration specifications.jpg
A device for in-situ fan airflow measurement, known as the Fan Assessment Numeration System (FANS) device, previously developed and constructed at the USDA-ARS Southern Poultry Research Laboratory, was refined at University of Kentucky as part of a project for quantifying building emissions from mechanically ventilated poultry and livestock…

Effect of growth promotant usage on Enterococci species on a poultry farm

Effect of growth promotant usage on Enterococci species on a poultry farm.JPG
The species population of enterococci isolated from four poultry houses for six grow-outs on one farm was determined. Two houses on the farm were control houses and did not use any antimicrobials, while two other houses on the farm used flavomycin, virginiamycin, and bacitracin during different poultry grow-outs. Litter, chick boxliners, feed, and…

Different Behavioral and Physiological Responses in Two Genetic Lines of Laying Hens After Transportation

Different Behavioral and Physiological Responses in Two Genetic Lines of Laying Hens After Transportation.JPG
Physiological and behavioral responses to transportation stress were examined in a chicken strain selected for high group productivity and survivability (HGPS) resulting from reduced cannibalism and flightiness in colony cages and in chickens from Dekalb XL (DXL) commercial strain. At 13 wk of age, 96 pullets per strain were randomly assigned to…

Genome-wide assessment of worldwide chicken SNP genetic diversity indicates significant absence of rare alleles in commercial breeds

Genome-wide assessment of worldwide chicken SNP genetic diversity indicates significant absence of rare alleles in commercial breeds.jpg
Breed utilization, genetic improvement, and industry consolidation are predicted to have major impacts on the genetic composition of commercial chickens. Consequently, the question arises as to whether sufficient genetic diversity remains within industry stocks to address future needs. With the chicken genome sequence and more than 2.8 million…

Influence of supplemental dietary poultry fat, phytase, and 25-hydroxycholecalciferol on the performance of commercial layers inoculated before or at the onset of lay with F-strain Mycoplasma gallisepticum

Influence of supplemental dietary poultry fat, phytase, and 25-hydroxycholecalciferol on the performance of commercial layers inoculated before or at the onset of lay with F-strain Mycoplasma gallisepticum.jpg
The effects of 2 levels of supplemental dietary poultry fat (PF) and the combination of PF, phytase (PHY), and 25-hydroxycholecalciferol (D(3)) on the performance of commercial layers inoculated with F-strain Mycoplasma gallisepticum (FMG) were investigated in 2 trials. Sham and FMG inoculations were administered at 12 (before lay) and 22 (early in…

Ideal Ratios of Isoleucine, Methionine, Methionine Plus Cystine, Threonine, Tryptophan, and Valine Relative to Lysine for White Leghorn-Type Laying Hens of Twenty-Eight to Thirty-Four Weeks of Age

Ideal Ratios of Isoleucine, Methionine, Methionine Plus Cystine, Threonine, Tryptophan, and Valine Relative to Lysine for White Leghorn-Type Laying Hens of Twenty-Eight to Thirty-Four Weeks of Age.jpg
Seven separate experiments were conducted with Hy-Line W-36 hens to determine the ideal ratio of Arg, Ile, Met, Met+Cys, Thr, Trp, and Val relative to Lys for maximal egg mass. The experiments were conducted simultaneously and were each designed as a randomized complete block design with 60 experimental units (each consisting of 1 cage with 2 hens)…

Evaluation of the bacterial diversity in cecal contents of laying hens fed various molting diets by using bacterial tag-encoded FLX amplicon pyrosequencing

Evaluation of the bacterial diversity in cecal contents of laying hens fed various molting diets by using bacterial tag-encoded FLX amplicon pyrosequencing.jpg
Laying hens are typically induced to molt to begin a new egg-laying cycle by withdrawing feed for up to 12 to 14 d. Fasted hens are more susceptible to colonization and tissue invasion by Salmonella enterica serovar Enteritidis. Much of this increased incidence in fasted hens is thought to be due to changes in the native intestinal microflora. An…

Effects of dietary alfalfa inclusion on Salmonella Typhimurium populations in growing layer chicks

Effects of dietary alfalfa inclusion on Salmonella Typhimurium populations in growing layer chicks.jpg
Reducing Salmonella in poultry has been a paramount goal of the poultry industry in order to improve food safety. Inclusion of high-fiber fermentable feedstuffs in chicken diets has been shown to reduce the incidence of Salmonella colonization in laying hens, but no work has been performed in growing birds. Therefore, the present study was…

Effects of organic selenium and zinc on the aging process of laying hens

Effects of organic selenium and zinc on the aging process of laying hens.jpg
The objective of the study was to determine whether supplementing the diets of post-molted hens with organic selenium (Se) (Sel-Plex®) and/or organic Zinc (Zn) (Bio-Plex®)1 could improve laying hen performance. Prior to molting, 120-78 wk old laying hens were separated into four treatment groups of 30 hens per treatment and were subjected to…

Market Power in Poultry Production Contracting? Evidence from a Farm Survey

Market Power in Poultry Production Contracting Evidence from a Farm Survey.jpg
The exercise of market power by broiler processing firms (integrators) is plausible because local markets for growers are concentrated and because growers face hold-up risks arising from substantial investments in specific assets set against limited integrator purchase commitments. This article explores the links between local integrator…

Lighting during grow-out and Salmonella in broiler flocks

Lighting during grow-out and Salmonella in broiler flocks.jpg
Background: Lighting is used during conventional broiler grow-out to modify bird behaviour to reach the goals of production and improve bird welfare. The protocols for lighting intensity vary. In a field study, we evaluated if the lighting practices impact the burden of Salmonella in broiler flocks. Methods: Conventional grow-out flocks reared in…

Vitamins A, E and fatty acid composition of the eggs of caged hens and pastured hens

Vitamins A, E and fatty acid composition of the eggs of caged hens and pastured hens.jpg
In the US farmers often market pastured poultry eggs for a premium price, claiming animal and human health benefits. We examined how moving pastured hens to forage legumes or mixed grasses influenced hen (Gallus gallus L.) egg omega-3 fatty acids and concentrations of vitamins A and E. We also compared the eggs of the pastured hens to those of hens…

The effect of perches in cages during pullet rearing and egg laying on hen performance, foot health, and plumage

The effect of perches in cages during pullet rearing and egg laying on hen performance, foot health, and plumage.jpg
Enrichment of pullet cages with perches has not been studied. Our objective was to determine if access to metal perches during all or part of the life cycle of caged White Leghorns affected egg traits, foot health, and feather condition. Treatment 1 represented control chickens that never had access to perches during their life cycle. Treatment 2…

Effects of Simple and Disposable Chicken Cages for Experimental Eimeria Infections

Effects of Simple and Disposable Chicken Cages for Experimental Eimeria Infections.jpg
During experimental Eimeria infections in chickens, facilities are often contaminated by fecal oocysts known to be highly resistant to both chemical and enzymatic treatments. Thus, studies using experimental Eimeria infections have been limited due to the difficulty of complete elimination of residual oocysts from both cages and facilities. To…

Effects of group size and repeated social disruption on the serotonergic and dopaminergic systems in two genetic lines of White Leghorn laying hens

Effects of group size and repeated social disruption on the serotonergic and dopaminergic systems in two genetic lines of White Leghorn laying hens.jpg
Farm practices such as increasing group size (GS) and mixing unfamiliar chickens may result in repeated social disruption (RSD) and affect the well-being of hens. To examine whether there are genetic differences in response to social stress, 2 genetic strains of White Leghorn hens were used [i.e., high group production and survivability (HGPS) and…

Enterobacteriaceae and related organisms isolated from nest run cart shelves in commercial shell egg processing facilities

Enterobacteriaceae and related organisms isolated from nest run cart shelves in commercial shell egg processing facilities.jpg
Enterobacteriaceae, including Salmonella, may be recovered from foods and processing facilities. High levels of Enterobacteriaceae in the processing plant environment can be an indication of inadequate sanitation. This experiment was designed to determine if nest run egg carts serve as reservoirs for Enterobacteriaceae. Eggs that are produced by…

Vertical Stratification of Ammonia in a Broiler House

Vertical Stratification of Ammonia in a Broiler House.jpg
The broiler industry is not immune to the problematic nature of NH3 production in animal rearing facilities. Though the headlines of today focus on environmental impact considerations, the detrimental effects of the house air quality on farmers and birds remain considerable for industry viability. This research investigated the vertical…

Poultry litter compost for suppression of root-knot nematode on cacao plants

Poultry litter compost for suppression of root-knot nematode on cacao plants.jpg
Poultry litter (poultry manure mixed with the wood shavings that are used for bedding or for covering the soil floor in poultry housing units) compost was investigated as an amendment for suppressing populations of Meloidogyne incognita and increasing plant vigor. The greenhouse and laboratory studies were conducted with mature compost produced in…

Volatile Fatty Acids in Suspended Particulate Matter from a Poultry House Using Rice Hulls as Bedding Materials — A Profile of First Flock after Total Cleanout

Volatile Fatty Acids in Suspended Particulate Matter from a Poultry House Using Rice Hulls as Bedding Materials.jpg
Livestock operations have long been associated with unpleasant odors whether it is a swine, poultry, or dairy operation. Unpleasant odorous smell has been generally accepted as part of livestock operations in the past. However, as more and more animal production continues to evolve into major concentrated operations, odor emissions from these…

Breeding of tomorrow’s chickens to improve well-being

Breeding of Tomorrows Chickens to Improve Well-Being.jpg
Chickens, as well as other animals, have the ability to change their behavior (behavioral plasticity) and physiology (physiological plasticity) based on the costs and benefits to fit their environment (adaptation). Through natural selection, the population preserves and accumulates traits that are beneficial and rejects those that are detrimental…