Population genetic structure of Santa Ins sheep in Brazil

摘要

This study aimed to describe the population genetic structure and evaluate the state of conservation of the genetic variability of Santa Ins sheep in Brazil. We used pedigree data of the Santa Ins breed available in electronic processing of the Brazilian Association of Sheep Breeders. A file with 20,206 records, which enabled the calculation of the genetic conservation index (GCI), individual inbreeding coefficient (F), change in inbreeding (Delta F), effective population size (Ne), effective number of founders (AE'(e)), effective number of ancestors (AE'(E)), generation interval (L), average relatedness coefficient of each individual (AR), and Wright's F-statistics (F (IT), F (IS), and F (ST)). For pedigree analysis and calculation of population parameters, the program ENDOG was used. The average inbreeding coefficient () was 0.97% and the mean average relatedness () 0.49%. The effective numbers of founders and ancestors were, respectively, 199 and 161. The average values of F and AR increased significantly over the years. The effective population size fluctuated over the years concurrently to oscillations in inbreeding rates, wherein N (e) reached just 68 in the year 2012. The mean average generation interval was 5.3 years. The Santa Ins breed in Brazil is under genetic drift process, with loss of genetic variation. It requires the implementation of a genetic management plan in the herd, for conservation and improvement of the breed.