Barnouin J, Bord S, Bazin S, Chassagne M
Animal Epidemiology Research Unit, INRA, 63122 Saint Genès Champanelle, France.
J Dairy Sci. 2005 Oct;88(10):3700-9. doi: 10.3168/jds.S0022-0302(05)73056-3.
An epidemiological prospective study was carried out in French dairy herds with Holstein, Montbéliarde, or Normande cows and with low herd somatic cell scores. The objective was to identify dairy management practices associated with herd incidence rate of clinical mastitis. The studied herds were selected on a national basis, clinical cases were recorded through a standardized system, and a stable dairy management system existed. In the surveyed herds, mean milk yield was 7420 kg/cow per yr and mean milk somatic cell score was 2.04 (132,000 cells/mL). Overdispersion Poisson models were performed to investigate risk factors for mastitis incidence rate. From the final model, the herds with the following characteristics had lower incidence rates of clinical mastitis: 1) culling of cows with more than 3 cases of clinical mastitis within a lactation; 2) more than 2 person-years assigned to dairy herd management; 3) balanced concentrate in the cow basal diet. Moreover, herds with the following characteristics had higher incidence rates of clinical mastitis: 1) milking cows loose-housed in a straw yard; 2) no mastitis therapy performed when a single clot was observed in the milk; 3) clusters rinsed using water or soapy water after milking a cow with high somatic cell count; 4) 305-d milk yield >7435 kg; 5) herd located in the South region; 6) herd located in the North region; 7) cows with at least 1 nonfunctional quarter; and 8) premilking holding area with a slippery surface. The underlying mechanisms of some highlighted risk factors, such as milk production level and dietary management practices, should be investigated more thoroughly through international collaboration.
在法国拥有荷斯坦、蒙贝利亚尔或诺曼底奶牛且群体体细胞评分较低的奶牛场中开展了一项流行病学前瞻性研究。目的是确定与临床乳腺炎群体发病率相关的奶牛场管理措施。研究的奶牛场是在全国范围内挑选出来的,临床病例通过标准化系统记录,并且存在稳定的奶牛场管理系统。在被调查的奶牛场中,平均产奶量为每年每头奶牛7420千克,平均牛奶体细胞评分为2.04(132,000个细胞/毫升)。采用过度分散泊松模型来研究乳腺炎发病率的风险因素。从最终模型来看,具有以下特征的奶牛场临床乳腺炎发病率较低:1)淘汰在一个泌乳期内发生超过3例临床乳腺炎的奶牛;2)分配给奶牛场管理的人年数超过2年;3)奶牛基础日粮中精料平衡。此外,具有以下特征的奶牛场临床乳腺炎发病率较高:1)在稻草场地散养挤奶的奶牛;2)当牛奶中观察到单个凝块时未进行乳腺炎治疗;3)在对体细胞计数高的奶牛挤奶后用水或肥皂水冲洗挤奶杯组;4)305天产奶量>7435千克;5)奶牛场位于南部地区;6)奶牛场位于北部地区;7)至少有一个无功能乳腺的奶牛;8)挤奶前存放区表面光滑。一些突出的风险因素,如产奶水平和日粮管理措施的潜在机制,应通过国际合作进行更深入的研究。