Dr. Naomi Botheras, Animal Welfare Program Specialist, The Ohio State University
Tail docking of dairy cattle has become common in the United States. Farmers suggest that the practice of tail docking reduces the transmission of diseases carried by cows, such as Leptospirosis, to workers. Producers also suggest docking improves ease of milking, and makes milking more comfortable for the workers because the shortened tail is less likely to hit people. Importantly, docking is also thought to improve cow cleanliness and udder health and hygiene, thereby decreasing somatic cell count (SCC) and the risk of mastitis.
While there are several perceived benefits of tail docking, it is also important to consider the effects of tail docking on the welfare or well-being of dairy cattle. There may be both short-term and long-term disadvantages to the cow associated with tail docking. These may include acute pain associated with the docking procedure, the possibility of chronic (long-term) pain in the tail stump, reduced ability of the cow to use its tail for communication and other normal functions, and altered ability of the cow to avoid flies. These possible disadvantages for the cow are welfare issues that should be considered alongside any possible benefits of tail docking.
Interestingly, a number of scientific studies have found no effect of tail docking on several of the suggested hygiene and cleanliness benefits of tail docking. Tucker et al. (2001) found no difference in a commercial free-stall barn between cows with intact tails and those that had been docked in terms of cleanliness, SCC, or cases of mastitis. Matthews et al. (1995) found similar results for cows on pasture with docked versus intact tails, with no difference in udder cleanliness, SCC, or incidence of mastitis. Eicher et al. (2001) also found no difference in udder cleanliness or SCC for docked and intact cows housed in a tie-stall barn, but they did find that docked cows were cleaner on their rear-quarters. In a substantial study with a large number of cows on 8 commercial free-stall farms observed over a 9-month period, Schreiner and Ruegg (2002) found no difference in SCC or intra-mammary infections between docked and intact dairy cows. These authors also found no difference in udder cleanliness scores, although there was a trend for docked cows to have slightly cleaner legs.
An obvious question is whether the welfare of tail docked cows is reduced because of either the inability of the animal to avoid flies or the disruption of important behaviors (such as feeding and lying) by the use of alternative fly-avoidance behaviors. Typical fly avoidance behaviors include running away, stomping, kicking, tail swishing, skin twitching, and head or ear movements. Increased fly loads are associated with disruption and alterations of eating patterns and increased energy expenditure in fly avoidance behaviors, which have implications for feed efficiency and consequently milk production and animal performance. It has been found that fly numbers are actually greater on tail docked cows and that docked cows show increased fly avoidance behaviors (Ladewig and Matthews, 1992; Eicher et al., 2001; Eicher and Dailey, 2002), which may have serious implications for animal performance.
Several European countries, including the United Kingdom, have prohibited tail docking of dairy cattle; however, no legislation in North America currently addresses this issue. However, tail docking is prohibited or not recommended in several animal welfare assurance/certification programs that have been developed for the U.S. dairy industry. Furthermore, the American Veterinary Medical Association (AVMA) opposes routine tail docking of cattle, stating "current scientific literature indicates that routine tail docking provides no benefit to the animal and that tail docking can lead to distress during fly seasons. When medically necessary, amputation of tails must be performed by a licensed veterinarian".
While some studies have indicated minimal adverse short-term effects from docking tails of dairy cattle using a rubber ring, no positive benefits to the cows have been identified, and potential long-term adverse effects of tail docking remain a possibility. These results suggest that with the possible exception of improved worker comfort, producers (and their cows) have little to gain from adopting the practice of routine tail docking of dairy cattle, as there may be disadvantages for the cows (e.g., pain and increased fly loads leading to increased fly avoidance behaviors) and also lack of cleanliness and udder health benefits. Until benefits for the cow of tail docking can be scientifically established, the routine tail docking of dairy cattle cannot be recommended. Investigation of alternative ways of improving cleanliness are warranted, as management decisions other than tail docking may play a more significant role in determining udder cleanliness and milk quality. For example, trimming the switch of the tail may offer an acceptable alternative to tail docking and should be considered whenever possible. Importantly, as tail docking of dairy cattle actually increases the fly load on the cow, if it is necessary to tail dock cows, particular attention to fly control is essential. This is important not only for the consideration of the cow's well-being, but also in terms of limiting effects on animal performance due to increased fly avoidance behavior.
References
Eicher, S.D., and J. W. Dailey. 2002. Indicators of acute pain and fly avoidance behaviors in Holstein calves following tail-docking. Journal of Dairy Science 85:2850-2858.
Eicher, S.D., J.L. Morrow-Tesch, J.L. Albright, and R.E. Williams. 2001. Tail-docking alters fly numbers, fly-avoidance behavior, and cleanliness, but not physiological measures. Journal of Dairy Science 84:1822-1828.
Ladewig, J., and L.R. Matthews. 1992. The importance of physiological measurements in farm animal stress research. Proceedings of the New Zealand Society of Animal Production 52:77-79.
Matthews, L.R., A. Phipps, G.A. Verkerk, D. Hart, J.N. Crockford, J.F. Carragher, and R.G. Harcourt. 1995. The effects of tail docking and trimming on milker comfort and dairy cattle health, welfare and production. In: Animal Behaviour and Welfare Research Centre, Hamilton, NZ, pp 1-25.
Schreiner, D.A., and P.L. Ruegg. 2002. Effects of tail docking on milk quality and cow cleanliness. Journal of Dairy Science 85: 2503-2511.
Tucker, C.B., D. Fraser, and D.M. Weary. 2001. Tail docking dairy cattle: Effects on cow cleanliness and udder health. Journal of Dairy Science 84: 84-87.