School of Agriculture and Food Science, University College Dublin, Dublin D04 V1W8, Ireland.
School of Agriculture and Food Science, University College Dublin, Dublin D04 V1W8, Ireland.
J Dairy Sci. 2021 Mar;104(3):3181-3196. doi: 10.3168/jds.2020-18676. Epub 2021 Jan 15.
This study used a stochastic simulation model to estimate the potential economic benefit of using sexed semen in heifers only and in heifers and lactating cows in a high-producing, pasture-based system under 3 fertility scenarios. Three breeding strategies were modeled: (1) only heifers inseminated with sexed semen and cows inseminated with conventional unsexed semen (SSH); (2) both heifers and cows inseminated with sexed semen (SSHC); and (3) a reference scenario in which all females were inseminated with conventional, unsexed semen (CONV). Each scenario was evaluated under 3 herd fertility states: high (HF), medium (MF), and low (LF), which, under the reference scenario, corresponded to herd replacement rates of 21, 25, and 31%, respectively. The model estimated the economic profit, including the net present value of the genetic gain from selection intensity. The economic return from adoption of sexed semen strategies declined, with reduced levels of baseline herd fertility turning negative in the LF state. The mean (±SD) sexed semen advantage (SSA) per cow for HF-SSH, MF-SSH, and LF-SSH scenarios were €30.61 ± 8.98, €27.45 ± 7.19, and €14.69 ± 11.06, respectively. However, the SSA per cow for HF-SSHC, MF-SSHC, and LF-SSHC scenarios were €49.14 ± 15.43, €18.46 ± 30.08, and -€19.30 ± 57.11. The range in economic profit for SSA for SSH was most sensitive to calf prices in HF-SSH and the pregnancy rate of sexed semen as a percentage of conventional unsorted semen in MF-SSH and LF-SSH. The range in economic profit for SSA for SSHC scenarios was most sensitive to the pregnancy rate of sexed semen as a percentage of conventional unsorted semen in HF-SSHC, MF-SSHC, and LF-SSHC. This study highlights the effect of baseline herd fertility state on the financial advantage of adopting sexed semen in a pasture-based dairy production system.
本研究使用随机模拟模型，在三种生育情景下，仅对小母牛使用性控精液，或同时对小母牛和泌乳牛使用性控精液，以此估计在高生产力、基于牧场的系统中使用性控精液的潜在经济效益。该模型模拟了三种繁殖策略：（1）仅对小母牛使用性控精液，对奶牛使用常规非性控精液（SSH）；（2）对小母牛和奶牛均使用性控精液（SSHC）；（3）一个参考方案，即所有母牛均使用常规非性控精液（CONV）。在三种牛群生育状态下评估了每个方案：高（HF）、中（MF）和低（LF），在参考方案下，这分别对应于牛群更替率为 21%、25%和 31%。该模型估计了经济利润，包括选择强度遗传增益的净现值。随着基础牛群生育力水平的降低，性控精液策略的经济效益下降，在 LF 状态下转为负值。HF-SSH、MF-SSH 和 LF-SSH 方案的每头牛的平均（±SD）性控精液优势（SSA）分别为€30.61 ± 8.98、€27.45 ± 7.19 和€14.69 ± 11.06。然而，HF-SSHC、MF-SSHC 和 LF-SSHC 方案的每头牛 SSA 分别为€49.14 ± 15.43、€18.46 ± 30.08 和-€19.30 ± 57.11。SSH 方案的 SSA 经济利润范围对 HF-SSH 中小牛价格和 MF-SSH 和 LF-SSH 中性控精液妊娠率占常规未分类精液的比例最为敏感。SSHC 方案的 SSA 经济利润范围对 HF-SSHC、MF-SSHC 和 LF-SSHC 中性控精液妊娠率占常规未分类精液的比例最为敏感。本研究强调了基础牛群生育状态对基于牧场的奶牛生产系统中采用性控精液的财务优势的影响。
