Impact of sex replacement strategies on the accuracy of estimated breeding value in beef cattle population

Abstract

The selection of replacement strategies for bulls and heifers in beef cattle populations is a pivotal aspect of livestock breeding programs, impacting genetic improvement and production outcomes. Despite its importance, there remains a dearth of comprehensive studies evaluating the influence of sex replacement strategies on the accuracy of estimated breeding values (EBVs). In this simulation study, various scenarios of male to female replacement ratios were explored using QMSim software to generate datasets representative of beef cattle populations. Our findings highlight the significance of balanced sex replacement strategies, with the scenario featuring a ratio of 40 males to 80 females (40M:80F) consistently demonstrating superior accuracy of EBVs across multiple generations compared to other scenarios. This enhanced accuracy is attributed to the maintenance of genetic diversity and effective mating strategies facilitated by a larger pool of breeding pairs. Conversely, scenarios with imbalanced sex ratios, such as 20M:40F, exhibited reduced accuracy due to limited genetic diversity and potential inbreeding effects. The enduring superiority of the 40M:80F scenario underscores its efficacy in providing reliable breeding value estimates and highlights the need for careful consideration of sex replacement strategies in optimizing genetic improvement programs. These findings contribute valuable insights to livestock breeding practices and emphasize the importance of adopting nuanced approaches to sex replacement strategies for sustainable genetic enhancement in beef cattle populations.