Washburn S P, White S L, Green J T, Benson G A
Department of Animal Science, North Carolina State University, Raleigh 27695, USA.
J Dairy Sci. 2002 Jan;85(1):105-11. doi: 10.3168/jds.S0022-0302(02)74058-7.
Dairy cows in confinement and pasture-based feeding systems were compared across four spring-calving and three fall-calving replicates for differences in reproduction, mastitis, body weights, and body condition scores. Feeding systems and replicates included both Jersey and Holstein cows. Cows in confinement were fed a total mixed ration, and cows on pasture were supplemented with concentrates and provided baled hay or haylage when pasture supply was limiting. Breeding periods were for 75 d in spring or fall. Reproductive performance did not differ significantly due to feeding system or season. Jerseys had higher conception rates (59.6 vs. 49.5 +/- 3.3%) and higher percentages of cows pregnant in 75 d (78.1 vs. 57.9 +/- 3.9%) than Holsteins. Cows in confinement had 1.8 times more clinical mastitis and eight times the rate of culling for mastitis than did cows on pasture. Jerseys had half as many clinical cases of mastitis per cow as Holsteins. Only 41 +/- 5% of confinement Holsteins remained for a subsequent lactation, starting within the defined calving season compared with 51 +/- 5% of pastured Holsteins and 71 and 72 +/- 5% of Jerseys, respectively. Body weights and condition scores were generally higher for confinement cows than pastured cows, and Jerseys had higher condition scores and lower body weights than Holsteins. In summary, pastured cows had fewer clinical cases of mastitis, lower body condition scores, and lower body weights than confinement cows. Holsteins were less likely to rebreed, had more mastitis, higher culling rates, and lower body condition scores than Jerseys.
对圈养和基于牧场饲养系统的奶牛进行了比较，在四个春季产犊和三个秋季产犊的重复试验中，比较了繁殖、乳腺炎、体重和体况评分方面的差异。饲养系统和重复试验包括泽西牛和荷斯坦牛。圈养的奶牛饲喂全混合日粮，牧场的奶牛补充精饲料，当牧场供应有限时提供干草捆或青贮饲料。春季或秋季的配种期为75天。繁殖性能在饲养系统或季节方面没有显著差异。泽西牛的受孕率（59.6%对49.5±3.3%）和75天内怀孕奶牛的百分比（78.1%对57.9±3.9%）高于荷斯坦牛。圈养的奶牛临床乳腺炎病例数是牧场奶牛的1.8倍，因乳腺炎而被淘汰的比率是牧场奶牛的8倍。每头泽西牛的临床乳腺炎病例数是荷斯坦牛的一半。在规定的产犊季节内开始下一个泌乳期时，只有41±5%的圈养荷斯坦牛留下来，而牧场荷斯坦牛的这一比例为51±5%，泽西牛分别为71%和72±5%。圈养奶牛的体重和体况评分通常高于牧场奶牛，泽西牛的体况评分高于荷斯坦牛，但体重低于荷斯坦牛。总之，与圈养奶牛相比，牧场奶牛的临床乳腺炎病例较少，体况评分较低，体重也较低。与泽西牛相比，荷斯坦牛再次配种的可能性较小，乳腺炎较多，淘汰率较高，体况评分较低。
