Rasmussen M D, Frimer E S, Kaartinen L, Jensen N E
Danish Institute of Agricultural Sciences, Research Centre Foulum, Tjele, Denmark.
J Dairy Res. 1998 Aug;65(3):353-63. doi: 10.1017/s0022029998002994.
The effects of milking cows with two different liners were measured for a period of 8 months with 115 Danish Holstein cows divided into two groups. Group H and L animals were milked with liners with mouthpiece cavity heights of 30 and 18 mm respectively (other dimensions also differed between the two liners). Average teat lengths of first lactation cows were 45 and 40 mm for front and rear teats. Older cows had teats approximately 10 mm longer. There was no difference in milk yield or milk flow rates between the two groups. Average machine-on time was shorter for group L, and first lactation cows of group L were less restive. The frequency of red and blue discoloured teats immediately after milking was higher for group H, and teat length increased on average 5 mm during lactation with no increase for group L. The small overall differences in udder health between the two groups were not significant. Udder health was better for first lactation cows of group L, even though liners of group L slipped more often and cows with recorded liner slip had poorer udder health. We conclude that special attention should be given to first lactation cows when liner type is selected for a herd. We propose that breeding programmes should ensure that teat length is kept above 50 mm.
对115头丹麦荷斯坦奶牛进行了为期8个月的实验，将其分为两组，测量使用两种不同内衬挤奶的效果。H组和L组动物分别使用吸嘴腔高度为30毫米和18毫米的内衬挤奶（两种内衬的其他尺寸也不同）。头胎奶牛前后乳头的平均长度分别为45毫米和40毫米。年龄较大的奶牛乳头大约长10毫米。两组之间的产奶量和奶流速度没有差异。L组的平均机器运行时间较短，L组的头胎奶牛较安静。挤奶后H组乳头立即出现红色和蓝色变色的频率较高，L组在泌乳期间乳头长度平均增加5毫米，L组则没有增加。两组之间乳房健康的总体差异较小，不显著。L组头胎奶牛的乳房健康状况更好，尽管L组的内衬更常滑落，记录有内衬滑落的奶牛乳房健康状况较差。我们得出结论，为牛群选择内衬类型时，应特别关注头胎奶牛。我们建议育种计划应确保乳头长度保持在50毫米以上。
