The prevalence of damaged tails in beef cows, pregnant dairy heifers and weaned dairy calves.

Abstract

Aims: To determine the prevalence of tail deviations, trauma and shortening in weaned dairy calves, pregnant dairy heifers and beef cows on a selection of New Zealand farms, and to compare results to those recorded in lactating dairy cows.

Methods: This was a cross-sectional observational study. For beef cows, 25 farms were randomly selected from two veterinary practices. For dairy heifers and calves, data were collected from farms (70 and 76, respectively) previously involved in a study of tail damage in lactating cows. All cattle were tail scored using a modification of the New Zealand Veterinary Association Scoring System. Tails were palpated and lesions recorded as deviated (non-linear deformity), shortened, or traumatic (all other lesions). Cows could have more than one lesion, but for the prevalence calculations, only the presence/absence of a particular lesion was assessed. Descriptive herd-level prevalence data were reported for all farms/cattle types. For dairy heifers, the prevalence of tail deviation was compared to that in adult cows on the same farm.

Results: For beef cattle, median prevalence of any tail damage was 4.0% (min 0.0, max 37.5%), and for deviations + trauma, it was 2.0% (min 0.0, max 16.7%). For dairy heifers, equivalent figures were 1.7% (min 0.0, max 17.8%) and 1.3% (min 0.0, max 17.8%). In weaned calves, the median prevalence of any damage was 0% (min 0.0, max 11.6%): almost all damage (61/64 cases) was deviation. Farms with a heifer prevalence of deviations > 2% had a mean cow prevalence of deviations 3.65 (95% CI = 0.7-6.6)% higher than herds with heifer prevalence ≤ 2%, but this explained only 9% of the variation in log percentage cow prevalence.

Conclusions and clinical relevance: In all groups, median prevalence of tail damage was low (and lower than reported in dairy cows), but individual farms had high levels of damage. Beef cows were more likely to have shortened or traumatised tails than dairy heifers/calves, perhaps from an increased prevalence of faecal tail rings. Limited association between the prevalence of tail deviations in heifers and lactating cows on the same farm, and generally lower levels of tail damage in heifers, do not support the hypothesis that tail damage in cows principally results from damage earlier in life. This study adds support to our hypothesis that poor handling/infrastructure are responsible for most tail damage in dairy cows.