Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison 53706.
Dairy Records Management Systems, Raleigh, NC 27603.
J Dairy Sci. 2023 May;106(5):3748-3760. doi: 10.3168/jds.2022-22494. Epub 2023 Mar 17.
Our objective was to characterize semen type prevalence and allocation to inseminate US Holstein and Jersey females by year, parity, service number, and herd size. A secondary objective was to identify the prevalence of beef breed sires selected to create beef × Holstein and beef × Jersey crossbred calves. The final data set included 8,244,653 total inseminations of 4,880,752 Holstein females across 9,155 herds, and 435,267 total inseminations of 266,058 Jersey females across 2,759 herds from October 2019 to July 2021. This data set represents approximately 42 and 27% of the total dairy cows and heifers, respectively, across approximately 40% of the total licensed dairy herds in the continental United States. Holstein and Jersey females were inseminated with 1 of 4 semen types: (1) beef, (2) conventional, (3) sexed, or (4) other dairy. The top 4 beef breeds used to produce beef × Holstein and beef × Jersey crossbred calves, respectively, were Angus (55.1 and 39.1%), Limousin (13.9, and 23.5%), Simmental (11.7 and 20.5%), and Crossbreed Beef (11.3 and 4.8%). From 2019 to 2021, the use of sexed semen to inseminate Holstein and Jersey females increased from 11.0 and 24.5% to 17.7 and 32.1%, respectively, and the use of beef semen to inseminate Holstein and Jersey females increased from 18.2 and 11.4% to 26.1 and 21.2%, respectively. The use of beef semen to inseminate Holstein and Jersey females increased with increasing parity and service number, whereas the use of sexed semen decreased with increasing parity and service number supporting that farmers used sexed semen more aggressively in higher fertility and younger females with greater genetic merit. Overall, the increase in sexed and beef semen inseminations was driven primarily by larger herds. In conclusion, sexed and beef semen inseminations in US Holstein and Jersey females increased from 2019 to 2021 and was allocated differentially based on parity and service number. This increase was driven primarily by larger dairy herds possibly due to differences in reproductive performance and economies of scale.
我们的目标是描述精液类型的流行情况,并根据年份、胎次、配种次数和牛群规模对美国荷斯坦奶牛和泽西奶牛进行配种。次要目标是确定用于培育肉牛×荷斯坦牛和肉牛×泽西牛杂交牛的肉牛品种公牛的流行情况。最终数据集包括 2019 年 10 月至 2021 年 7 月期间,9155 个牛群中 4880752 头荷斯坦奶牛的 8244653 次总配种记录,以及 2759 个牛群中 266058 头泽西奶牛的 435267 次总配种记录。该数据集代表了美国大陆约 40%的许可奶牛群中,分别约 42%和 27%的奶牛和小母牛。荷斯坦奶牛和泽西奶牛分别使用 4 种精液类型中的 1 种进行配种:(1)肉牛,(2)常规,(3)性别鉴定,或(4)其他奶牛。分别用于生产肉牛×荷斯坦牛和肉牛×泽西牛杂交牛的前 4 大肉牛品种是安格斯牛(55.1%和 39.1%)、利木赞牛(13.9%和 23.5%)、西门塔尔牛(11.7%和 20.5%)和杂种肉牛(11.3%和 4.8%)。从 2019 年到 2021 年,用于荷斯坦奶牛和泽西奶牛配种的性别鉴定精液的使用比例从 11.0%和 24.5%分别增加到 17.7%和 32.1%,用于荷斯坦奶牛和泽西奶牛配种的肉牛精液的使用比例从 18.2%和 11.4%分别增加到 26.1%和 21.2%。随着胎次和配种次数的增加,荷斯坦奶牛和泽西奶牛使用肉牛精液的比例增加,而使用性别鉴定精液的比例下降,这表明农民在更高的生育能力和更年轻、遗传潜力更大的母牛中更积极地使用性别鉴定精液。总体而言,性别鉴定精液和肉牛精液的配种量增加主要是由较大的牛群推动的。总之,2019 年至 2021 年间,美国荷斯坦奶牛和泽西奶牛的性别鉴定精液和肉牛精液配种量有所增加,并且根据胎次和配种次数进行了不同的分配。这种增加主要是由较大的奶牛场推动的,这可能是由于繁殖性能和规模经济的差异。