Boujenane Ismaïl, El Aimani Jalila, By Khalid
Department of Animal Production and Biotechnology, Institut Agronomique et Vétérinaire Hassan II, PO Box 6202, Rabat-Instituts, 10101, Rabat, Morocco,
Trop Anim Health Prod. 2015 Jan;47(1):207-11. doi: 10.1007/s11250-014-0711-5. Epub 2014 Nov 4.
The aim of this study was to determine the influence of clinical mastitis and time of first mastitis occurrence on reproductive and milk performance of Holstein cows. Data were collected in a dairy farm from 2008 to 2012 on 1725 cows, among which 464 cows with mastitis. To determine the influence of clinical mastitis on reproductive and milk performance, models included fixed effects of parity, calving season, calving year, and group (cows with and with no mastitis). To determine the effect of time of 1st mastitis occurrence on reproductive performance, the mastitic cows group was further reclassified into three groups: prior to 60 days, between 60 and 90 days and greater than 90 days postpartum. For milk performance, the mastitic cows group was divided into two groups: before and after peak milk yield. Clinical mastitis had significant effects on calving to first AI interval, milk yield, and fat yield, but a non-significant effect on days open, number of inseminations per conception, and milk fat percentage. Mastitic cows had a calving to first AI interval 6.1 days longer and 549.6 kg milk and 20.4 kg fat per 305 days of lactation lower than those with no mastitis. Time of 1st mastitis occurrence did not have any significant effect on reproductive performance. Further, milk and fat yields of cows diseased before peak milk yield were 506 kg and 23.9 kg, respectively, lower than those of cows affected after peak milk yield. Extra attention needs to be paid to mastitis during the early postpartum period.
本研究的目的是确定临床型乳腺炎及首次发生乳腺炎的时间对荷斯坦奶牛繁殖性能和产奶性能的影响。2008年至2012年期间，在一个奶牛场收集了1725头奶牛的数据，其中464头患有乳腺炎。为了确定临床型乳腺炎对繁殖性能和产奶性能的影响，模型纳入了胎次、产犊季节、产犊年份和组别（患乳腺炎和未患乳腺炎的奶牛）等固定效应。为了确定首次发生乳腺炎的时间对繁殖性能的影响，患乳腺炎的奶牛组进一步重新分为三组：产后60天之前、60至90天之间以及产后90天之后。对于产奶性能，患乳腺炎的奶牛组分为两组：产奶高峰之前和之后。临床型乳腺炎对产犊至首次人工授精间隔、产奶量和脂肪产量有显著影响，但对空怀天数、每次受孕的输精次数和乳脂率无显著影响。患乳腺炎的奶牛产犊至首次人工授精间隔比未患乳腺炎的奶牛长6.1天，每305天泌乳期的产奶量低549.6千克，脂肪产量低20.4千克。首次发生乳腺炎的时间对繁殖性能没有任何显著影响。此外，产奶高峰之前患病的奶牛的产奶量和脂肪产量分别比产奶高峰之后患病的奶牛低506千克和23.9千克。产后早期需要格外关注乳腺炎。
