Population genetic structure of Santa Inês sheep in Brazil

• Published in: Tropical animal health and production Vol. 50; no. 3; pp. 503 - 508
• Main Authors: Rego Neto, Aurino de Araújo, Rocha Sarmento, José Lindenberg, Pereira da Silva Santos, Natanael, Guimarães Campelo, José Elivalto, Silva Sena, Luciano, Biagiotti, Daniel, Vieira dos Santos, Gleyson
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-03-2018; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Breeding; Coefficients; Conservation; Genetic diversity; Genetic drift; Genetic structure; Genetic variability; Inbreeding; Life Sciences; Mathematical analysis; Oscillations; Ovis aries; Pedigree; Population; Population genetics; Population number; Regular Articles; Sheep; Statistical analysis; Veterinary Medicine/Veterinary Science; Zoology; Brazil; Inbreeding; Hair sheep; Effective size; Genetic management
• ISSN: 0049-4747; 1573-7438
• DOI: 10.1007/s11250-017-1459-5

This study aimed to describe the population genetic structure and evaluate the state of conservation of the genetic variability of Santa Inês sheep in Brazil. We used pedigree data of the Santa Inês 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 (Δ
F
), effective population size (Ne), effective number of founders (ƒ
e
), effective number of ancestors (ƒ
ɑ
), 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 (
F
¯
) was 0.97% and the mean average relatedness (
AR
¯
) 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 Inês 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.