Advances in molecular genetic techniques applied to selection for litter size in goats (Capra hircus): a review
Luciano Gomes de Lima, Namíbia Oliveira Balbino de Souza, Raisa Rodrigues Santos Rios, Breno Araújo de Melo, Lays Thayse Alves dos Santos, K.M. Silva, Thomas W Murphy, Angelina Bossi Fraga
Abstract
Litter size, or prolificacy, in goats is defined as the number of kids born per doe kidding. Improving litter size through selection not only directly enhances producer profitability as more progeny can be marketed but can also increase genetic gains in other traits due to greater selection intensity. However, most traits associated with reproduction have low heritability, and genetic improvement will be slow if the selection is based on one or a few phenotypic records. In the absence of a genetic evaluation programme with extensive pedigrees and performance recording, phenotypic selection for litter size is not promising. Advances in molecular genetic techniques may serve as an alternative to increase genetic progress in prolificacy. Several techniques have been developed to elucidate the mechanisms involved in phenotypic expression at the DNA level. Although recent research has identified genomic regions associated with several production traits in goats, litter size has not been extensively researched. Nevertheless, recent advancements in molecular genetic have created new opportunities for the improvement of litter size in goats. The development of next generation molecular tools to identify genomic genetic variants has made it possible to apply whole-genome scanning techniques, genome-wide association studies, and genomic selection to improve goat prolificacy.