Animal Molecular Breeding 2024, Vol.14, No.4, 252-261 http://animalscipublisher.com/index.php/amb 255 4.3 Addressing reproductive efficiency Reproductive efficiency is another area where quantitative genetics is applied in livestock breeding. Traits related to reproduction, such as fertility and litter size, are complex and influenced by many genetic and environmental factors. By utilizing quantitative genetic principles, breeders can identify genetic markers associated with reproductive traits and select animals with superior breeding values (Viana et al., 2016; Schmid and Bennewitz, 2017). This approach helps in optimizing reproductive performance and increasing the overall productivity of livestock populations. Techniques like genomic selection, which uses SNP markers to predict breeding values, have shown promise in improving reproductive traits. In summary, quantitative genetics provides a framework for enhancing productivity, health, and reproductive efficiency in livestock breeding. By leveraging genetic information and advanced breeding techniques, breeders can achieve significant improvements in these key areas, ultimately leading to more efficient and sustainable livestock production systems. 5 Case Study: Application of Quantitative Genetics in Dairy Cattle Breeding 5.1 Background and significance of dairy cattle breeding Dairy cattle breeding has evolved significantly over the past century, driven by the need to improve milk production and adapt to changing environmental and market demands. Initially, the focus was on increasing milk yield, but over time, the breeding goals have expanded to include traits such as fertility, health, and longevity, reflecting a more balanced approach to breeding (Figure 2) (Miglior et al., 2017; Weigel et al., 2017). The advent of genomic technologies has revolutionized the field, allowing for more precise selection and faster genetic progress (Gutierrez-Reinoso et al., 2021; Ma and Lin, 2024). This shift is crucial for meeting the growing global demand for dairy products while ensuring the sustainability and welfare of dairy cattle. Figure 2 Recording of performance data for dairy cows then (1936, left panels) and now (2017, right panel) (Adopted from Weigel et al., 2017) 5.2 Use of heritability and breeding values in selecting high-yielding cows Heritability and breeding values are fundamental concepts in quantitative genetics, used extensively in dairy cattle breeding to select high-yielding cows. Heritability estimates the proportion of phenotypic variation in a trait that is attributable to genetic differences among individuals. Traits such as milk yield have moderate to high heritability, making them suitable targets for selection (Kadri et al., 2015; Brajković et al., 2024). Breeding values, which
RkJQdWJsaXNoZXIy MjQ4ODYzNA==