MILKING PERFORMANCE AND UDDER HEALTH OF COWS MILKED WITH 2 DIFFERENT LINERS

The effects of milking cows with two different liners were measured fo r a period of 8 months with 115 Danish Holstein cows divided into two groups. G-roup H and L animals were milked with liners with mouthpiece cavity]heights of 30 and 18 mm respectively (other dimensions also di ffered between the two liners). Aver age teat lengths of first lactati on cows were 45 and 40 mm for front and rear teats. Older cows had tea ts similar to 10 min longer. There was no difference in milk yield or milk flow rates between the two groups. Average machine-on time was sh orter for group L, and first lactation cows of group L were less resti ve. 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 d ifferences in udder health between the two groups were not significant . Udder health was better for first lactation cows of group L, even th ough liners of group L slipped more often and cows with recorded liner slip had poorer udder health. We conclude that special attention shou ld be given to first lactation cows when liner type is selected for a herd. We propose that breeding programmes should ensure that teat leng th is kept above 50 mm.