Genetic Characterization of Indubrasil Cattle Breed Population.

Ricardo Zanella,Giovana Zanella,Marcos Da Silva,Nathã De Carvalho,Luísa Lago,Fernanda Facioli,Arthur Da Silva,Fábio Pértille,João Do Carmo Panetto

doi:10.3390/vetsci5040098

Abstract

The Indubrasil breed was developed in the Brazilian region called Triângulo Mineiro as a result of a cross between zebu cattle. Initially, it was used as a terminal cross and currently it represents approximately 4.45% of all the Brazilian zebu cattle. Studies were conducted to estimate genetic parameters in the Indubrasil using pedigree information, however, until now, no study has been developed using large-scale genomic markers in this breed. Pedigree information are widely used to investigate population parameters; however, they can neglect some estimates when compared to the use of genomic markers. Therefore, the objective of this study was to investigate the population structure and the genetic diversity of Indubrasil cattle using a high-density Single Nucleotide Polymorphism (SNP) panel (Illumina BovineHD BeadChip 700k). Levels of genomic homozygosity were evaluated using three different approaches: Runs of homozygosity (FROH), % of homozygosis (FSNP), and inbreeding coefficient (Fx). Further, Runs of Homozygosity (ROH) segments conserved among the animals were investigated to identify possible regions associated with the breed characteristics. Our results indicate that even the Indubrasil breed having a small effective population size, the levels of homozygosity (FROH = 0.046) are still small. This was possibly caused by the cross conducted among different breeds for its development. It suggests no immediate risks associated with loss of genetic variation. This information might be used in breeding programs, for the breed conservation and for the expansion of the Indubrasil breed.

Highlights

The Indubrasil breed was the first zebuine breed developed in Brazil, in the Triângulo Mineiro region
735,293 Single Nucleotide Polymorphism (SNP) were identified to be located on the autosomal
Using the runs of homozygosis (FROH ), we have identified an average of FROH = 0.04 ± 0.035, minimum of 0.0126 and maximum of 0.18 (Table 4)

Summary

Introduction

The Indubrasil breed was the first zebuine breed developed in Brazil, in the Triângulo Mineiro region. This breed originated from a cross between the Guzera, Gir, and Nelore breeds, with the objective to maximize the genetic gain of all zebus in only one breed [1]. Between the years of 1925 to 1945, the production of Indubrasil cattle in the country had increased, and in 1946, some of these animals were even exported to the United States for the development of the American Brahman breed (ABCZ). The Indubrasil breed represents 4.45% of zebu animals raised in Brazil (ABCZ)

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Discussion

Conclusion