Mahle D E, Galton D M, Adkinson R W
J Dairy Sci. 1982 Jul;65(7):1252-7. doi: 10.3168/jds.S0022-0302(82)82338-2.
Effects of vacuum and pulsation ratio on udder health were studied for 36 first parity animals in a 60-day trial. Treatments consisted of vacuum at 33.3, 41.6, and 50 kPa at pulsation ratios of 50:50, 60:40, and 70:30 at 60 pulsations per min. All teats were exposed to a culture broth of Staphylococcus aureus after machine removal. Numbers of intramammary infections and somatic cells were determined. Analysis for number of intramammary infections indicated no significant differences among treatments for number of infected available quarters. Trend for intramammary infections was that as pulsation ratio widened, the number of infected available quarters increased, especially at the ratio 70:30. As vacuum increased, number of infected available quarters increased. Least squares means of Wisconsin Mastitis Test scores were 6.29, 5.57, and 6.68 for 33.3 kPa; 12.18, 3.82, and 7.86 for 41.6 kPa; and 9.11, 6.40, and 15.02 for 50 kPa at pulsation ratios 50:50, 60:40, and 70:30. There were significant differences among treatments for vacuum and pulsation ratio. Wisconsin Mastitis Test data indicated an interaction between vacuum and pulsation ratio. Optimum predicted vacuum and pulsation ratio based on Wisconsin Mastitis Test data were 27.2 kPa and 62:38.
在一项为期60天的试验中，对36头初产动物研究了真空度和脉动率对乳房健康的影响。处理包括在每分钟60次脉动下，真空度分别为33.3、41.6和50 kPa，脉动率分别为50:50、60:40和70:30。机器挤奶后，所有乳头均暴露于金黄色葡萄球菌培养液中。测定乳房内感染数量和体细胞数量。乳房内感染数量分析表明，各处理间可用感染乳头数量无显著差异。乳房内感染的趋势是，随着脉动率增大，可用感染乳头数量增加，尤其是在70:30的比例下。随着真空度增加，可用感染乳头数量增加。在脉动率50:50、60:40和70:30时，33.3 kPa的威斯康星乳房炎试验分数的最小二乘均值分别为6.29、5.57和6.68；41.6 kPa时分别为12.18、3.82和7.86；50 kPa时分别为9.11、6.40和15.02。各处理间的真空度和脉动率存在显著差异。威斯康星乳房炎试验数据表明真空度和脉动率之间存在交互作用。基于威斯康星乳房炎试验数据预测的最佳真空度和脉动率分别为27.2 kPa和62:38。
