Persson Waller K, Westermark T, Ekman T, Svennersten-Sjaunja K
Department of Ruminant and Porcine Diseases, National Veterinary Institute, SE-751 89 Uppsala, Sweden.
J Dairy Sci. 2003 Nov;86(11):3488-97. doi: 10.3168/jds.S0022-0302(03)73953-8.
Milk leakage (ML), or milk observed dripping or flowing from one or more teats between milkings, has been associated with increased risk of udder infections and mastitis in dairy cows. Preliminary observations indicate that ML might occur more often in automatic milking systems (AMS) than in conventional milking systems (CMS), but comparative data on the incidence of ML in AMS or in CMS are not available. Therefore, the occurrence of ML at various observation periods was studied in one AMS with cows housed in a free-stall barn in comparison to CMS with cows housed either in a free-stall barn or a tie-stall barn and milked at regular intervals in a herringbone milking parlor. Relationships between ML and other cow and management factors were also examined. In each of 2 yr, all cows (n = 230 total; 46 cows present both years) were observed at 2-h intervals during six 24-h periods. At least one ML occurred in 39.0 (AMS) vs. 11.2% (CMS) of individual cows and in 16.2 (AMS) vs. 2.9% (CMS) of 24-h cow days studied. Milk leakage was not related to milk production, parity, stage of lactation, or estrous status. However, in the AMS, 62% of primiparous and 28% of multiparous cows leaked milk at least once. Milk leakage occurred more often in rear than in forequarters. Cows were usually lying down when ML was observed, but intervals from previous milking varied, especially in AMS. In AMS, about one-fifth of the ML observations occurred < or = 4 h after milking, and half of those were associated with disturbances at the previous milking. Milk flow rate was higher in quarters leaking milk than in other quarters. Strategies to reduce milk leakage in AMS may be important to minimize potential risks of udder disease.
乳汁泄漏（ML），即在挤奶间隔期间观察到乳汁从一个或多个乳头滴下或流出，与奶牛乳房感染和乳腺炎风险增加有关。初步观察表明，ML在自动挤奶系统（AMS）中可能比在传统挤奶系统（CMS）中更常发生，但目前尚无关于AMS或CMS中ML发生率的比较数据。因此，本研究将一个自由牛舍中采用AMS挤奶的奶牛群，与自由牛舍或拴系牛舍中采用CMS并在鱼骨式挤奶厅定期挤奶的奶牛群进行了比较，研究了不同观察期内ML的发生情况。同时还考察了ML与其他奶牛及管理因素之间的关系。在连续两年中，每年在六个24小时时间段内每隔2小时对所有奶牛（共230头；两年均有46头）进行观察。在所研究的个体奶牛中，至少发生一次ML的比例在AMS组为39.0%，而在CMS组为11.2%；在24小时奶牛日中，这一比例在AMS组为16.2%，而在CMS组为2.9%。乳汁泄漏与产奶量、胎次、泌乳阶段或发情状态无关。然而，在AMS组中，62%的初产奶牛和28%的经产奶牛至少有一次乳汁泄漏。后躯比前躯更常发生乳汁泄漏。观察到ML时奶牛通常处于躺卧状态，但距上次挤奶的时间间隔各不相同，尤其是在AMS组。在AMS组中，约五分之一的ML观察发生在挤奶后≤4小时，其中一半与上次挤奶时的干扰有关。乳汁泄漏的乳腺区乳汁流速高于其他乳腺区。在AMS中减少乳汁泄漏的策略对于将乳房疾病的潜在风险降至最低可能很重要。
