Department of Animal Science, University of Minnesota, St. Paul 55108.
Department of Animal Science, University of Minnesota, St. Paul 55108.
J Dairy Sci. 2017 Nov;100(11):9447-9458. doi: 10.3168/jds.2017-12824. Epub 2017 Aug 23.
Montbéliarde (MO) × Holstein (HO) and Viking Red (VR) × HO crossbred cows were compared with pure HO cows in 8 large, high-performance dairy herds in Minnesota. All cows calved for the first time from December 2010 to April 2014. Fertility and survival traits were calculated from records of insemination, pregnancy diagnosis, calving, and disposal that were recorded via management software. Body condition score and conformation were subjectively scored once during early lactation by trained evaluators. The analysis of survival to 60 d in milk included 536 MO × HO, 560 VR × HO, and 1,033 HO cows during first lactation. Cows analyzed for other fertility, survival, and conformation traits had up to 13% fewer cows available for analysis. The first service conception rate of the crossbred cows (both types combined) increased 7%, as did the conception rate across the first 5 inseminations, compared with the HO cows during first lactation. Furthermore, the combined crossbred cows (2.11 ± 0.05) had fewer times bred than HO cows (2.30 ± 0.05) and 10 fewer d open compared with their HO herdmates. Across the 8 herds, breed groups did not differ for survival to 60 d in milk; however, the superior fertility of the crossbred cows allowed an increased proportion of the combined crossbreds (71 ± 1.5%) to calve a second time within 14 mo compared with the HO cows (63 ± 1.5%). For survival to second calving, the combined crossbred cows had 4% superior survival compared with the HO cows. The MO × HO and VR × HO crossbred cows both had increased body condition score (+0.50 ± 0.02 and +0.25 ± 0.02, respectively) but shorter stature and less body depth than HO cows. The MO × HO cows had less set to the hock and a steeper foot angle than the HO cows, and the VR × HO cows had more set to the hock with a similar foot angle to the HO cows. The combined crossbred cows had less udder clearance from the hock than HO cows, more width between both front and rear teats, and longer teat length than the HO cows; however, the frequency of first-lactation cows culled for udder conformation was uniformly low (<1%) across the breed groups.
蒙贝利亚（MO）×荷斯坦（HO）和维金红（VR）×HO 杂交奶牛与纯种荷斯坦奶牛在明尼苏达州的 8 个大型高绩效奶牛场进行了比较。所有奶牛均于 2010 年 12 月至 2014 年 4 月首次分娩。通过管理软件记录的配种、妊娠诊断、分娩和处理记录，计算了繁殖力和存活率特征。体况评分和结构由经过培训的评估员在泌乳早期进行主观评分。对 60 d 产奶期的生存分析包括 536 头 MO×HO、560 头 VR×HO 和 1033 头 HO 奶牛的首胎。对其他繁殖力、存活率和结构特征进行分析的奶牛，可分析的奶牛数量减少了 13%。与首胎荷斯坦奶牛相比，杂交奶牛（两种类型的组合）的首次受胎率提高了 7%，前 5 次配种的受胎率也有所提高。此外，与荷斯坦奶牛相比，杂交奶牛（2.11±0.05）的配种次数更少，发情天数也少了 10 天。在 8 个牛群中，不同品种组在 60 d 产奶期的存活率上没有差异；然而，杂交奶牛的优良繁殖力使得更多的杂交奶牛（71±1.5%）能够在 14 个月内再次产犊，而其荷斯坦奶牛的比例为 63±1.5%。对于再次产犊的存活率，杂交奶牛的存活率比荷斯坦奶牛高 4%。MO×HO 和 VR×HO 杂交奶牛的体况评分均有所提高（分别为+0.50±0.02 和+0.25±0.02），但比荷斯坦奶牛矮，体躯深度浅。MO×HO 奶牛的后肢角度比荷斯坦奶牛陡，跗关节更结实，而 VR×HO 奶牛的跗关节角度与荷斯坦奶牛相似，但更结实。与荷斯坦奶牛相比，杂交奶牛的跗关节与后肢之间的乳房间隙较小，前乳区和后乳区之间的宽度更大，乳区长，然而，首次产犊的奶牛因乳房结构而被淘汰的频率在各品种组中均较低（<1%）。
