|Cushman, Robert - Bob|
Submitted to: Workshop Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 11/1/2012
Publication Date: 12/3/2012
Citation: Cushman, R.A., Perry, G.A. 2012. What we know about the genetics of reproduction. Proceedings, Applied Reproductive Strategies in Beef Cattle, Sioux Falls, SD, December 3-4, 2012. pp. 165-173. Interpretive Summary:
Technical Abstract: Animal breeding and reproductive physiology have been closely related throughout the history of animal production science, because artificial insemination provides the best method of increasing the influence of sires with superior genetics to improve production traits. The addition of genetic technologies to this paradigm allows for improved methods of selecting sires and dams carrying the best genes for production and yield of edible products and resistance to diseases and parasites. However, decreasing the number of influential parents within a population also increases the risk of propagating a recessive gene that could negatively impact the species (Ghanem and Nishibori, 2009; Meyers et al., 2010). Antagonistic genotypic relationships between production traits and fertility (Johnston et al., 2009; Collis et al., 2012) suggest that care must be taken to ensure that increasing the frequency of genes with a positive influence on production does not negatively impact the fertility of the replacement females entering the herd. The use of genetic technologies to improve reproduction have been slow in domestic farm species, mostly due to the relatively low heritability of these traits (Cushman et al., 2008; Cammack et al., 2009). Among reproductive traits, those with the greatest heritability are associated with sexual maturity (Table.1), probably because these traits depend on the animal attaining a certain age, body mass or body composition (Gargantini et al., 2005; Johnston et al., 2009). The tight relationship between growth and development genes and reproductive success suggests that genetic technologies must be used with care to improve production efficiency without negatively impacting fertility, and suggest a need for genetic markers of fertility to develop selection indices that do not focus solely on production traits.