Genomic predictions for productive traits using a multibreed genomic matrix in Nellore, Brahman and Guzerá cattle

• Grant number: 23/03659-5
• Support Opportunities: Scholarships in Brazil - Master
• Start date: July 01, 2023
• End date: December 31, 2024
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Genetics and Improvement of Domestic Animals
• Principal Investigator: Fernando Sebastián Baldi Rey
• Grantee: Gabriel Gubiani
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

In this project, the objective is to analyze different strategies for the evaluation of a metapopulation composed of the Nelore, Brahman, and Guzerá breeds, using the single-step genomic method - BLUP for reproductive, growth and carcass quality characteristics, namely: calving probability (3P), weight-adjusted at 15 months of age (P450), loin eye area (AOL) and rump fat thickness (P8), with approximately 100,000, 200,000, 80,000 and 80,000 phenotypic observations, respectively, from the breeding program for the Nelore (Nellore Brasil program), Guzerá (Guzerá Brasil program) and Brahman (Brahman Brasil program) breeds of the National Association of Breeders and Researchers (ANCP), Ribeirão Preto, SP. As specific objectives, there are a) Evaluate different strategies for obtaining the G matrix, implemented in the ssGBLUP method, in Brahman, Guzerá, and Nellore cattle, considering 1) G1: traditional approach (default) of ssGBLUP; 2) G2: the G matrix will be centered on the specific allele frequencies of each race; 3) G3: The G matrix will be centered and scaled to race-specific allele frequencies; b) Evaluate the impact of using weighted genomic matrices on the variance components for AOL, P8, 3P, and P450; c) To verify the impact of using weighted genomic matrices on genomic predictions for AOL, P8, 3P and P450, bias and prediction ability in genotyped young animals. The results of this project will allow: Evaluating of the impact of the implementation of the multi-breed genomic evaluation of Zebu beef breeds using different approaches; Evaluate of the technical and economic viability of genomic evaluations using ssGBLUP in populations of beef cattle breeds with reduced size of the reference population; Implement statistical methodologies for the use of genomic data in animal breeding, aiming at multi-breed evaluation in Zebu breeds.