Genetic evaluation is possible on community pastoral small ruminant flocks in the presence of multiple sires and uncertain of paternity

• Published in: Small ruminant research Vol. 151; pp. 72 - 81
• Main Authors: Carneiro, Francisco Flávio Dias, Lôbo, Ana Maria Bezerra Oliveira, Silva, Luciano Pinheiro da, Silva, Kleibe de Moraes, Landim, Aline Vieira, Lôbo, Raimundo Nonato Braga
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2017
• Subjects: Bayesian analysis; Breeding values; Heritability; Real data; Simulation; Heritability; Breeding values; Simulation; Bayesian analysis; Real data
• ISSN: 0921-4488; 1879-0941
• DOI: 10.1016/j.smallrumres.2017.04.017

•Modern genetic evaluation on community pastoral small ruminant flocks is made difficult by the uncertain of paternity.•Hierarchical model and average numerator of relationship matrix methods perform genetic evaluation with paternity uncertainty.•Genetic evaluation models that consider multiple sires and paternity uncertain are efficient to estimate genetic parameters.•HM and ANRM methods produce similar estimates and may be considered in genetic evaluations. Many sheep flocks in the world are raised collectively, in a communal way, where animals of different owners graze together. These conditions make it difficult or impossible to identify the paternity of the offspring, since several sires and dams can mate without any control. This practice inhibits the achievement of accurate genetic evaluations using the animal model procedures. Therefore, it is proposed here to evaluate the efficiency of the use of two methods, the hierarchical animal model (HM) and the average numerator relationship matrix (ANRM), in the estimation of genetic parameters and breeding values ​​of sheep, with uncertainty of paternity in which there are mating in the presence of multiple sires. The methods were compared in two situations, one with a simulated trait with a phenotypic variance of 7.5kg2, an average of 14.5kg and a heritability of 0.30, so that the true genetic parameters were known, and the other with real data, with weights at birth and weaning of animals of a flock of Santa Inês sheep breed. The results confirmed that genetic evaluation models with multiple sires, which consider paternity uncertainty, are efficient in estimating genetic parameters and ranking superior sires in sheep flocks with community pastoral characteristics. Despite the best fit of the data by HM, both models were similar for the estimates and can be considered in the genetic evaluations.