Variance of gametic diversity estimation for economically important traits of Nellore cattle

• Grant number: 21/09942-5
• Support Opportunities: Scholarships in Brazil - Doctorate
• Effective date (Start): March 01, 2022
• Effective date (End): July 31, 2024
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Genetics and Improvement of Domestic Animals
• Principal Investigator: Lucia Galvão de Albuquerque
• Grantee: Patrícia Iana Schmidt
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil
• Associated research grant: 17/10630-2 - Genetic aspects of meat production quality, efficiency and sustainability in Nelore breed animals, AP.TEM

Abstract

The aim of this study is to estimate the variance of gametic diversity of potential breeding animals for economically important traits using recombination rates between SNP markers and SNP marker effects and finally, to compare the response to selection for the traits considering or not the variance of gametic diversity. Some reproductive traits to be considered are scrotal circumference, age at first calving and heifer pregnancy and performance traits: body weight at weaning and at yearling. Phenotypic records measured on approximately 250,000 Nellore animals from commercial breeding programs will be used. Approximately 60,000 genotyped Nellore animals provided by three commercial breeding programs from Alliance Nellore dataset (www.gensys.com.br) will be available for the study. Recombination rates will be measured by an indirect method using pedigree. Progeny-dam-sire trios genotyped will be extracted from the pedigree of Nellore cattle and phased to infer sex-specific recombination events during meiosis. The heritability for recombination rate will be estimate using a repeatability model. We will use a model assuming homogeneity of variance of marker effects, GBLUP (SNPBLUP). The Gamevar.f90 software will be used to estimate variance of gametic diversity and the coefficient of relative variation. Finally, we will test the implementation of the variance of gametic diversity combined with breeding value into a selection index for Nellore and to compare the response to selection considering or not the variance of gametic diversity. (AU)