Department of Animal Science, University of Minnesota, St. Paul 55108.
Department of Animal Science, University of Minnesota, St. Paul 55108.
J Dairy Sci. 2020 Nov;103(11):10917-10939. doi: 10.3168/jds.2020-18604. Epub 2020 Sep 28.
Three generations of crossbreds from a 3-breed rotation of the Viking Red (VR), Montbéliarde (MO), and Holstein (HO) breeds were compared with their HO herdmates in 7 commercial dairy herds in Minnesota. The designed study enrolled 3,550 HO females in 2008 to initiate crossbreeding and a control of pure HO herdmates within each herd. Service sires were high-ranking, proven AI bulls selected for high genetic merit within each of the VR, MO, and HO breeds. Cows in this study calved from 2010 to 2017 and collection of data ended on December 31, 2017. The first generation of cows consisted of 644 VR × HO and 616 MO × HO crossbreds and their 1,405 HO herdmates. The second generation had 615 VR × MO/HO and 568 MO × VR/HO crossbreds and their 1,462 HO herdmates. The third generation had 466 combined HO × VR/MO/HO and HO × MO/VR/HO crossbreds and their 736 HO herdmates. Total health cost was the sum of veterinary treatment cost, pharmaceutical cost, and farm labor cost to treat 16 different health disorders. Conformation traits and body condition score were subjectively scored once during early lactation for each of the first 3 lactations of cows. Total health cost of the 2-breed crossbreds was significantly lower during first (-23%), second (-29%), and third (-21%) lactation compared with their HO herdmates. For the 3-breed crossbreds, total health cost did not differ during first lactation but was -26% lower during both second and third lactation compared with their HO herdmates. The stillbirth rate for calves born to 2-breed crossbred dams (4%) was significantly lower compared with calves born to their HO herdmates (8%) at first calving. Survival from first to third calving (+9%) and first to fourth calving (+11%) was significantly higher for the 2-breed crossbreds compared with their HO herdmates. Also, the 3-breed crossbreds had significantly higher survival to third (+11%) and fourth (+19%) calving compared with their HO herdmates. Across each generation of crossbreeding, the crossbreds had uniformly shorter stature, less angularity, and less body depth compared with their respective HO herdmates. The crossbred cows also had significantly less udder clearance from the hock but significantly more rear teat width and longer teat length compared with their respective HO herdmates. Furthermore, the crossbred cows had higher body condition score compared with their HO herdmates during each of their first 3 lactations.
从维金红(VR)、蒙贝利亚尔(MO)和荷斯坦(HO)三种品种的三系杂交中,选择了三个杂交代与明尼苏达州 7 个商业奶牛场的 HO 同窝小牛进行比较。这项设计研究于 2008 年招募了 3550 头 HO 母牛,开始进行杂交,并对每个牛群中的纯 HO 同窝小牛进行了对照。服务种公牛是高排名的、经过验证的人工授精公牛,在 VR、MO 和 HO 品种中均具有高遗传价值。本研究中的奶牛于 2010 年至 2017 年分娩,数据收集于 2017 年 12 月 31 日结束。第一代奶牛由 644 头 VR × HO 和 616 头 MO × HO 杂交奶牛及其 1405 头 HO 同窝小牛组成。第二代有 615 头 VR × MO/HO 和 568 头 MO × VR/HO 杂交奶牛及其 1462 头 HO 同窝小牛。第三代有 466 头混合 HO × VR/MO/HO 和 HO × MO/VR/HO 杂交奶牛及其 736 头 HO 同窝小牛。总健康成本是兽医治疗费用、药品费用和农场劳动力成本的总和,用于治疗 16 种不同的健康疾病。在每头奶牛的前 3 个泌乳期中的早期泌乳期,对 conformation 性状和体况评分进行了一次主观评分。与 HO 同窝小牛相比,两代杂交奶牛的第一(-23%)、第二(-29%)和第三(-21%)泌乳期的总健康成本显著降低。对于三系杂交奶牛,第一泌乳期的总健康成本没有差异,但与 HO 同窝小牛相比,第二和第三泌乳期的总健康成本分别降低了 26%。与 HO 同窝小牛相比,两代杂交奶牛的产犊死产率(4%)显著降低(8%)。与 HO 同窝小牛相比,两代杂交奶牛的第一至第三产犊(+9%)和第一至第四产犊(+11%)的存活率显著提高。同样,与 HO 同窝小牛相比,三代杂交奶牛的第三(+11%)和第四(+19%)产犊的存活率也显著提高。在每一代杂交中,杂交奶牛与各自的 HO 同窝小牛相比,体型更矮,角度更小,体深更小。与各自的 HO 同窝小牛相比,杂交奶牛的后肢跗关节处的乳房间隙明显较小,但后乳区宽度明显较大,乳区长度明显较长。此外,与 HO 同窝小牛相比,杂交奶牛在其前 3 个泌乳期中的体况评分更高。