Wells S J, Trent A M, Marsh W E, Robinson R A
Department of Clinical and Population Sciences, College of Veterinary Medicine, University of Minnesota, St Paul 55108.
J Am Vet Med Assoc. 1993 Jan 1;202(1):78-82.
An epidemiologic study investigating the prevalence of lameness in lactating dairy cows was performed in 17 dairy herds in Minnesota and Wisconsin. The mean herd size was 50 cows. Cows from 14 herds were housed in stanchions or tie stalls, and cows from 3 herds in free stalls or dry lot. During visits to each farm in the summer and subsequent spring, 2 investigators simultaneously but independently evaluated the ambulation of lactating cows by use of a standardized scoring system. The lameness scoring system was reliable at the 2 visits, with 92.7 and 91.3% agreement between the 2 observers and kappa coefficients of 0.60. The prevalence of lameness detected by the investigators ("clinical" lameness) was 13.7% (117/853) in summer and 16.7% (134/801) in spring in lactating dairy cows. These prevalences were 2.5 times higher than those estimated by the herd managers. Parity was significantly (P < or = 0.03) associated with lameness, with higher prevalence of clinical lameness found in cows of higher parity.
在明尼苏达州和威斯康星州的17个奶牛场进行了一项调查泌乳期奶牛跛足患病率的流行病学研究。平均牛群规模为50头奶牛。来自14个牛群的奶牛饲养在固定栏或系栏中，来自3个牛群的奶牛饲养在自由栏或干栏中。在夏季和随后的春季对每个农场进行走访时，2名调查人员同时但独立地使用标准化评分系统评估泌乳期奶牛的行走情况。跛足评分系统在两次走访时都很可靠，两名观察者之间的一致性为92.7%和91.3%，kappa系数为0.60。调查人员检测到的跛足患病率（“临床”跛足）在夏季泌乳期奶牛中为13.7%（117/853），在春季为16.7%（134/801）。这些患病率比牛群管理者估计的患病率高2.5倍。胎次与跛足显著相关（P≤0.03），胎次较高的奶牛临床跛足患病率更高。
