Roche Steven M, Ross Joseph A, Schatz Crystal, Beaugrand Kendall, Zuidhof Sjoert, Ralston Brenda, Allan Nick, Olson Merle
ACER Consulting, Guelph, ON N1G 2W1, Canada.
Chinook Contract Research Inc., Airdrie, AB T4A 0C3, Canada.
Animals (Basel). 2023 Jan 19;13(3):346. doi: 10.3390/ani13030346.
This study investigated the effects of dystocia on milk production, somatic cell count, reproductivity, disease, and milk production. A total of 2159 cows across 21 dairy farms in Alberta, Canada were enrolled in this study. Multivariable models were created to explore associations between outcome variables and calving ease score. In total, 89.5% of calvings were unassisted, 6.1% were an easy pull, and 4.3% were a moderate-hard pull. Cows that had a moderate-hard pull produced 4.01 kg less milk, 0.12 kg less volume of milk fat, and 0.12 kg less milk protein per day than those that had an unassisted calving. No difference was found between calving ease groups with respect to SCC. Cows with a moderate or hard pull produced 510 kg less milk per lactation than unassisted cows. Cows with a moderate to high level of assistance at birth had a higher hazard of being culled over the duration of their lactation. Cows with an easy pull had increased odds of developing a retained placenta. It is evident that assistance at calving, particularly a moderate-hard pull, is associated with significant impacts on future milk production and risk of being culled; therefore, efforts should be made to minimize dystocia and prevent these impacts.
本研究调查了难产对产奶量、体细胞计数、繁殖性能、疾病以及产奶量的影响。加拿大艾伯塔省21个奶牛场的2159头奶牛参与了本研究。构建多变量模型以探索结果变量与产犊难易度评分之间的关联。总体而言，89.5%的产犊无需助产，6.1%为轻松拉出，4.3%为中等难度至困难拉出。与无需助产的奶牛相比，中等难度至困难拉出的奶牛每天产奶量少4.01千克，乳脂肪产量少0.12千克，乳蛋白产量少0.12千克。在体细胞计数方面，产犊难易度组之间未发现差异。中等或困难拉出的奶牛每个泌乳期的产奶量比无需助产的奶牛少510千克。出生时助产程度为中等至高的奶牛在泌乳期被淘汰的风险更高。轻松拉出的奶牛发生胎盘滞留的几率增加。显然，产犊时的助产，尤其是中等难度至困难拉出，会对未来的产奶量和被淘汰风险产生重大影响；因此，应努力尽量减少难产并防止这些影响。
