Paape M J, Weinland B T
Milk Secretion and Mastitis Laboratory, US Department of Agriculture, Agricultural Research Service, Beltsville, MD 20705.
J Dairy Sci. 1988 Jan;71(1):250-6. doi: 10.3168/jds.S0022-0302(88)79549-1.
The study was conducted to determine effects of an abraded intramammary device on milk yield, tissue damage, and milk somatic cells during late lactation. Abraded intramammary devices were inserted into diagonally opposed quarters of 20 cows. One group of 11 cows (devices inserted 30 wk of lactation) was quarter machine milked daily for 2 wk before and for 8 wk after insertion. Nine cows had devices inserted within 4 wk postpartum and were quarter milked at 20 and 40 wk of lactation. Aliquots of quarter bucket milk were obtained for determination of milk somatic cells, red blood cells, and NAGase activity. Stripping milk was obtained for milk somatic cell counts. For both groups, there was no significant effect of the abraded intramammary device on NAGase activity. There was a tendency for quarters with devices to produce less milk than control quarters, but the difference was not significant. Milk SCC were significantly elevated in quarter bucket and stripping milk from quarters containing intramammary devices. Red blood cells were higher in quarters containing intramammary devices when compared with controls. Results indicate that abraded intramammary devices increased concentrations of somatic cells and red blood cells in bucket milk, did not damage tissue as measured by NAGase activity, and loss in milk production was nonsignificant.
本研究旨在确定磨损的乳房内装置对泌乳后期奶牛产奶量、组织损伤和乳体细胞的影响。将磨损的乳房内装置插入20头奶牛对角的两个乳区。一组11头奶牛（在泌乳30周时插入装置）在插入前每天进行2周的乳区机械挤奶，插入后进行8周。9头奶牛在产后4周内插入装置，并在泌乳20周和40周时进行乳区挤奶。采集乳区桶奶的等分试样，用于测定乳体细胞、红细胞和N-乙酰-β-D-氨基葡萄糖苷酶（NAGase）活性。采集剥脱乳用于乳体细胞计数。对于两组，磨损的乳房内装置对NAGase活性均无显著影响。带有装置的乳区产奶量有低于对照乳区的趋势，但差异不显著。含有乳房内装置的乳区桶奶和剥脱乳中的乳体细胞计数显著升高。与对照相比，含有乳房内装置的乳区红细胞数量更高。结果表明，磨损的乳房内装置会增加桶奶中体细胞和红细胞的浓度，通过NAGase活性测定未发现对组织有损伤，且产奶量损失不显著。
