| Autor: |
Santana ML; Grupo de Melhoramento Animal de Mato Grosso (GMAT), Instituto de Ciências Agrárias e Tecnológicas, Universidade Federal de Rondonópolis (UFR), Rondonópolis 78735-901, Brazil., Bignardi AB; Grupo de Melhoramento Animal de Mato Grosso (GMAT), Instituto de Ciências Agrárias e Tecnológicas, Universidade Federal de Rondonópolis (UFR), Rondonópolis 78735-901, Brazil., Pereira RJ; Grupo de Melhoramento Animal de Mato Grosso (GMAT), Instituto de Ciências Agrárias e Tecnológicas, Universidade Federal de Rondonópolis (UFR), Rondonópolis 78735-901, Brazil., Oliveira Junior GA; Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada., Freitas AP; Centro de Pesquisa em Bovinos de Corte, Instituto de Zootecnia (IZ), Sertãozinho 14160-900, Brazil., Carvalheiro R; Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista (UNESP), Jaboticabal 14884-900, Brazil., Eler JP; Grupo de Melhoramento Animal e Biotecnologia (GMAB), Departamento de Medicina Veterinária, FZEA, Universidade de São Paulo (USP), Pirassununga 13635-900, Brazil., Ferraz JBS; Grupo de Melhoramento Animal e Biotecnologia (GMAB), Departamento de Medicina Veterinária, FZEA, Universidade de São Paulo (USP), Pirassununga 13635-900, Brazil., Cyrillo JNSG; Centro de Pesquisa em Bovinos de Corte, Instituto de Zootecnia (IZ), Sertãozinho 14160-900, Brazil., Mercadante MEZ; Centro de Pesquisa em Bovinos de Corte, Instituto de Zootecnia (IZ), Sertãozinho 14160-900, Brazil. |
| Abstrakt: |
The prenatal environment is recognized as crucial for the postnatal performance in cattle. In tropical regions, pregnant beef cows commonly experience nutritional restriction during the second half of the gestation period. Thus, the present study was designed to analyze the genotype by prenatal environment interaction (G × Epn) and to identify genomic regions associated with the level and response in growth and reproduction-related traits of beef cattle to changes in the prenatal environment. A reaction norm model was applied to data from two Nelore herds using the solutions of contemporary groups for birth weight as a descriptor variable of the gestational environment quality. A better gestational environment favored weights until weaning, scrotal circumference at yearling, and days to first calving of the offspring. The G × Epn was strong enough to result in heterogeneity of variance components and genetic parameters in addition to reranking of estimated breeding values and SNPs effects. Several genomic regions associated with the level of performance and specific responses of the animals to variations in the gestational environment were revealed, which harbor QTLs and can be exploited for selection purposes. Therefore, genetic evaluation models considering G × Epn and special management and nutrition care for pregnant cows are recommended. |
