Population structure and genetic diversity of Boer goat breed in Brazil

Abstract

Information about population structure of domestic breeds is essential to provide effective guidelines in order to increase productivity based on genetic improvement programs. Therefore, the purpose of this study was to describe and analyze the genetic diversity and population structure of Boer goat breed in Brazil. A pedigree data from 22,650 individuals born between 1980 and 2019 and recorded by the Brazilian Association of Goat Breeders was analyzed in terms of completeness, average generation interval, gene origin probability, average kinship coefficient, inbreeding coefficient, and genetic conservation index, using the software ENDOG 4.8. The ancestry was known for 84.06 %, 77.38 %, 72.43 %, 68.00 % and 59.34 % of samples in the first, second, third, fourth and fifth parentage, respectively. The average number of complete, equivalent and maximum generations over a 40-year period was equal to 2.79, 4.86 and 8.22, respectively. The mean interval between generations was 3.27 (+/−2.13). A total of 2013 founders and 1881 ancestors was determined, while the effective number of founders and ancestors were established in 262 and 68, respectively. The 44 main ancestors were responsible for 50.02 % of the total genetic variance in Boer breed. The average relationship coefficient was determined in 1.61 % while the average inbreeding coefficient was equal to 3.41 %. Both parameters were higher (2.09 and 4.96, respectively) in populations composed of two or more complete generations. The average genetic conservation index was 22.90, including seven animals with values above 100. The high quantity (75.31) of inbred individuals from two or more generations requires particular attention. On the other hand, the identification of animals that descend from a high quantity of founders in their pedigree indicate they can be used to keep or increase the genetic diversity in further generations.