Japertiene R, Juozaitiene V, Kriauziene J, Rudejeviene J, Japertas S
Lithuanian Veterinary Academy, Department of Animal Breeding and Genetics, Tilzes 18, Kaunas, LT-47181, Lithuania.
Pol J Vet Sci. 2007;10(4):255-61.
The investigation was conducted during 2005-2006 on 4010 dairy cows. Having performed statistical data analysis, we determined that the lowest somatic cell count (SCC) in Red and Red-White cow population was obtained when the milking time was 5-6 min., milking speed was higher than 1.5 kg/min., high milk flow was from 2.51 to 4 kg/min., and in Black-White cow population having a milking time was higher than 7 min., milking speed was from 1.01 to 2 kg/min., a high milk flow --from 2.01 to 4 kg/min. (p<0.001). In Red and Red-White cow population with subclinical mastitis, milking time was longer and milking speed was slower than in healthy cows. High milk flow values were least in healthy Black-White cow population. This determines a more equal milk flow which is desired in milking cows mechanically. Most sensitive to udder infection are 1st lactation cows which have a higher milk flow. A larger phenotype correlation coefficient in Red and Red-White cow population was between the SCC and milking time (-0.089, p<0.01) and between high milk flow (0.086, p<0.01) and milk yield (-0.071, p<0.05). However in Black-White cow population, correlation was found between SCC and milk yield (-0.117, p<0.01) and milking speed (-0.110, p<0.01). Contagious mastitis pathogens were identified in Red and Red-White cow milk samples primarily from productive cows having a milking speed of 1.01-1.5 kg/min., and in Black-White cow population having a milking speed of 1.51-2.0 kg/min.
2005年至2006年期间，对4010头奶牛进行了调查。在进行统计数据分析后，我们确定，红白花奶牛群体中，挤奶时间为5 - 6分钟、挤奶速度高于1.5千克/分钟、高奶流速度为2.51至4千克/分钟时，体细胞计数（SCC）最低；而黑白花奶牛群体中，挤奶时间高于7分钟、挤奶速度为1.01至2千克/分钟、高奶流速度为2.01至4千克/分钟时，体细胞计数最低（p<0.001）。与健康奶牛相比，患有亚临床乳腺炎的红白花奶牛群体挤奶时间更长，挤奶速度更慢。健康黑白花奶牛群体的高奶流值最低。这决定了在机械挤奶时需要更均匀的奶流。头胎泌乳奶牛对乳房感染最敏感，它们的奶流速度更高。红白花奶牛群体中，SCC与挤奶时间之间的表型相关系数更大（-0.089，p<0.01），高奶流速度与产奶量之间的表型相关系数也更大（0.086，p<0.01），产奶量与挤奶速度之间的表型相关系数为-0.071（p<0.05）。然而在黑白花奶牛群体中，SCC与产奶量之间存在相关性（-0.117，p<0.01），与挤奶速度之间也存在相关性（-0.110，p<0.01）。在红白花奶牛的牛奶样本中，主要从挤奶速度为1.01 - 1.5千克/分钟的高产奶牛中鉴定出了传染性乳腺炎病原体；在黑白花奶牛群体中，主要从挤奶速度为1.51 - 2.0千克/分钟的奶牛中鉴定出了传染性乳腺炎病原体。
