Animal Welfare Information Center Bulletin, Winter 2001-Spring 2002, Vol. 11 No. 3-4

Tail Docking in Dairy Cattle

C. B. Tucker and D. M. Weary
Animal Welfare Program
Faculty of Agricultural Sciences and Centre for Applied Ethics
University of British Columbia

Increasingly, North American dairy farmers are choosing to tail dock their cows. Tail docking is most commonly carried out at two ages: a few weeks before first calving or just after weaning in calves. There are two main methods of docking. When docki ng adults, it is most common to place a tight rubber ring on the tail approximately 12 cm below the vulva. After 1-3 weeks, the lower portion of the tail is removed. The rubber ring method is also used with calves; however, some farmers tail dock their ca lves using a docking iron.

The practice of tail docking dairy cattle first became common in New Zealand. The practice was thought to reduce transmission to workers of diseases carried by the cows, such as Leptospirosis. However, research indicates that other measures, like improve d worker hygiene, are more effective in controlling disease transmission (Mackintosh et al. 1980). A second reason for docking was that it made milking more comfortable for workers because the shortened tail was less likely to hit people. This is thought to be particularly true in parlors where milking occurs between the legs. In North America, where the procedure is now gaining foothold, farmers cite other reasons for docking including cow cleanliness and udder health. Docking is thought to improve cow c leanliness because the tail can transfer feces onto the cow. Cleaner cows should be exposed to fewer pathogens and therefore experience improved udder health.

Two photographs that show 1) a cow without its tail docked and 2) a cow with its tail docked.

We recently tested the cow cleanliness and udder health claims by performing an experiment on a commercial free-stall dairy farm in British Columbia. The farmer had decided to dock his 500 milking-cow herd, but for the purposes of our experiment agreed t o leave approximately half of the herd intact for 8 weeks. During this time, we compared cow cleanliness, udder cleanliness, and udder health. We found no difference between cows with intact tails and those that had been docked in terms of any of our clea nliness measures, somatic cell counts (a measure of udder health), or cases of mastitis as diagnosed by the herd veterinarian. Another New Zealand study, examining animals on pasture, also found no difference in cleanliness between cows with tails and tho se that had been docked (Matthews et al. 1995). These results suggest that with the possible exception of improved worker comfort, producers (and their cows) have little to gain from adopting this procedure.

There may also be disadvantages associated with docking, including pain associated with the procedure and impaired fly control. Perhaps surprisingly, existing evidence suggests that the pain due to docking is relatively mild. Work by Petrie et al. (1995, 1996) showed no changes in plasma cortisol (a measure of stress) in response to docking, and only a portion of the docked calves showed behavioral responses to the procedure, such as vocalizing and tail shaking. Adult animals do show some response in the hours that follow application of the ring, including swelling, tail swishing, and an increase in plasma cortisol (Wilson 1972). New research on the pain associated with docking is now being conducted at USDA and the University of Guelph. Even if cows do not find docking very painful, there is good evidence that docking impairs their ability to control flies. Three studies have found more flies on docked animals (Matthews et al. 1995; Phipps et al. 1995, Wilson 1972). And Phipps et al. (1995) reported mor e fly removal behaviors, such as tail flicking and leg stamping, by docked cows than by animals with an intact tail. Cows may also use their tails in other ways, such as in social signaling, but to date we know little about this aspect of tail use.

Given that there are these disadvantages and that we could find no cleanliness and udder health benefits associated with docking, we see little merit in adopting this procedure. Several European countries including Norway, Sweden, the Netherlands, the Un ited Kingdom, and Switzerland have prohibited tail docking of dairy cattle. However, no legislation in North America currently addresses the issue of tail docking dairy cattle.


Mackintosh, C.G., L.M. Schollum, R.E. Harris, D.K. Blackmore, A.F. Willis, N.R. Cook, and J.C.J. Stoke. 1980. Epidemiology of leptospirosis in dairy farm workers in the Manawatu Part I: A cross-sectional serological survey and associated occupational factors. N.Z. Vet. J. 28:245-250.

Matthews, L.R., A. Phipps, G.A. Verkerk, D. Hart, J.N. Crockford, J.F. Carragher, and R.G. Harcourt. 1995. The effects of taildocking and trimming on milker comfort and dairy cattle health, welfare and production. Animal Behaviour and Welfare Research Ce ntre, Hamilton, N.Z.

Petrie, N. J., D.J. Mellor, K.J. Stafford, R.A. Bruce, and R.N. Ward. 1996. Cortisol responses of calves to two methods of tail docking used with or without local anaesthetic. N.Z. Vet. J. 44: 4-8.

Petrie, N.J., K.J. Stafford, D.J. Mellor, R.A. Bruce, and R.N. Ward. 1995. The behaviour of calves tail docked with a rubber ring used with or without local anaesthesia. Proc. N.Z. Soc. Anim. Prod. 55:58-60.

Phipps, A.M., L. R. Matthews, and G.A. Verkerk, 1995. Tail docked dairy cattle: fly induced behaviour and adrenal responsiveness to ACTH. Proc. N.Z. Soc. Anim. Prod. 55:61-63.

Wilson, G.D.A. 1972. Docking cows’ tails. Proc. Ruakura Farmer Conference., Ruakura, New Zealand:158-165.

This article appeared in the Animal Welfare Information Center Bulletin, Volume 11, Number 3-4, Winter 2001-Spring 2002

Go to:
Contents, Animal Welfare Information Center Bulletin
Top of Document

The Animal Welfare Information Center
U.S. Department of Agriculture
Agricultural Research Service
National Agricultural Library
10301 Baltimore Ave.
Beltsville, MD 20705-2351

Phone: (301) 504-6212
FAX: (301) 504-5181
Contact us:

Policies and Links

U S D A logo A R S logo N A L logo
June 18, 2013
This page's URL is