Rutherford K M D, Langford F M, Jack M C, Sherwood L, Lawrence A B, Haskell M J
Animal Behaviour and Welfare, Sustainable Livestock Systems, Scottish Agricultural College, West Mains Rd., Edinburgh, EH9 3JG, Scotland.
J Dairy Sci. 2008 Jun;91(6):2265-74. doi: 10.3168/jds.2007-0847.
The presence of hock injury was assessed in the milking herds of 80 dairy farms (40 organic, 40 nonorganic) across the United Kingdom. A wide range of information on farm management and husbandry was gathered via interview to assess the factors contributing to hock damage for all 80 farms, and a comprehensive building appraisal was conducted for 40 farms visited during the winter housing period. The prevalence of hock lesions was lower on organic compared with nonorganic farms (37.2 vs. 49.1%). Prevalence of hock damage was greater in the spring than fall (59.9 vs. 21.6%) and cows housed in free-stalls had a greater prevalence of hock lesions than those housed on straw (46.0 vs. 25.0%). Prevalence of hock damage increased with lactation number. In the analysis of fall/spring data, the age first mated, herd biosecurity, duration of summer grazing, and cow milk yield were significant factors relating to herd hock damage. Larger herds had a greater proportion of cows with hock swellings. Farms with a shorter calving interval had more cows with hock swellings. Factors relating to housing conditions that were positively associated with the prevalence of hock damage were low feed face space per cow, inferior passageway cleanliness, low total standing area per cow, and the type of bedding added to the free-stall. To assess whether free-stall versus straw-pen or organic versus nonorganic farms had different sets of risk factors, the data were reanalyzed for these types separately. For the straw-pen farms a high culling rate was associated with more hock damage. Within nonorganic farms, the length of summer grazing was significant, with longer periods meaning less hock injury. The prevalence of hock injuries on many UK farms, both organic and non-organic, exceeded levels that are deemed acceptable for cow comfort. Efforts are needed to improve housing standards to reduce the prevalence of hock injury and consequently improve cow welfare.
在英国80个奶牛场（40个有机农场、40个非有机农场）的挤奶牛群中评估跗关节损伤情况。通过访谈收集了关于农场管理和饲养的广泛信息，以评估这80个农场中导致跗关节损伤的因素，并在冬季圈舍期对40个受访农场进行了全面的建筑评估。与非有机农场相比，有机农场的跗关节损伤患病率较低（37.2%对49.1%）。春季跗关节损伤患病率高于秋季（59.9%对21.6%），且饲养在自由牛栏中的奶牛跗关节损伤患病率高于饲养在稻草上的奶牛（46.0%对25.0%）。跗关节损伤患病率随产次增加而上升。在秋季/春季数据分析中，初配年龄、牛群生物安全、夏季放牧时长和奶牛产奶量是与牛群跗关节损伤相关的重要因素。规模较大的牛群中跗关节肿胀的奶牛比例更高。产犊间隔较短的农场中跗关节肿胀的奶牛更多。与跗关节损伤患病率呈正相关的圈舍条件因素包括每头奶牛的饲料采食面空间小、通道清洁度差、每头奶牛的总站立面积小以及添加到自由牛栏中的垫料类型。为评估自由牛栏与稻草围栏或有机农场与非有机农场是否存在不同的风险因素集，分别对这些类型的数据进行了重新分析。对于稻草围栏农场，高淘汰率与更多的跗关节损伤相关。在非有机农场中，夏季放牧时长具有显著性，时长越长意味着跗关节损伤越少。许多英国农场（包括有机农场和非有机农场）的跗关节损伤患病率超过了奶牛舒适度可接受的水平。需要努力提高圈舍标准以降低跗关节损伤患病率，从而改善奶牛福利。
