Barnum D A, Meek A H
Can J Comp Med. 1982 Jan;46(1):12-6.
Somatic cell counts were performed monthly on bulk tank milk samples for all producers in the Ontario counties of Hastings, Lennox/Addington and Prince Edward throughout 1978 and 1979. Other data were obtained via a structured questionnaire and from the records of the Ontario Milk Marketing Board. Many producers have not adopted practices that have been advocated for the integrated control of mastitis. For example, 43.3% of producers surveyed used single service paper towels, 63.3% regularly used teat dip and 56.5% dry cow therapy. The mean of the average monthly somatic cell count for all producers for 1978 was 621.1 x 10(3) cells/mL. This latter value was used to divide the producers into case (higher than average) and control (lower than average) groups. Control herds averaged 95.9 liters more shipped milk per cow per month than case herds. Milk from control herds averaged 0.22 percentage points higher than case herds for each of average fat and lactose, and 0.16 percentage points higher for protein. The linear regression of monthly shipped milk on the respective monthly bulk tank somatic cell count indicated a loss of 13.26 L/cow/month for each 100,000 increase in somatic cell count.
1978年至1979年期间，每月对黑斯廷斯、伦诺克斯/阿丁顿和爱德华王子等安大略省各县所有生产商的大罐牛奶样本进行体细胞计数。其他数据通过结构化问卷以及安大略省牛奶销售委员会的记录获得。许多生产商尚未采用所倡导的乳腺炎综合防治措施。例如，接受调查的生产商中，43.3%使用一次性服务纸巾，63.3%经常使用乳头浸液，56.5%进行干奶牛治疗。1978年所有生产商的月平均体细胞计数平均值为621.1×10³个细胞/毫升。利用该数值将生产商分为病例组（高于平均值）和对照组（低于平均值）。对照组牛群每月每头牛的牛奶发货量比病例组平均多95.9升。对照组牛奶的平均脂肪含量和乳糖含量均比病例组高0.22个百分点，蛋白质含量高0.16个百分点。每月发货牛奶量与相应月份大罐体细胞计数的线性回归表明，体细胞计数每增加10万，每头牛每月的牛奶损失量为13.26升。
