Pedigree analysis of Brazilian Morada Nova hair sheep
Publication date: Available online 12 November 2018
Source: Small Ruminant Research
Author(s): Concepta McManus, Olivardo Facó, Luciana Shiotsuki, José Luiz Jivago de Paula Rolo, Vanessa Peripolli
The aim of this study was to describe the population structure of Morada Nova sheep breed using pedigree analysis to support development strategies for conservation and breeding programs. Data was available on 10,015 Morada Nova animals born between 1973 and 2014, registered by ARCO (Brazilian Association of Sheep Breeders). The animals were divided into three categories: (1) Base: animals of unknown origin showing strong breed morphology; (2) Prov: animals with genealogy control for one (Prov I), two (Prov II) or three (Prov III) complete generations; (3) PO: animals with four or more complete generations of controlled genealogy. Data was analyzed using the ENDOG software v4.8 to determine individual inbreeding (F), effective population size (Ne), effective number of founders (fe), effective number of ancestors (fa) and number of founder genome equivalents (fg), generation intervals (Int) and genetic conservation index (GCI), of the Morada Nova sheep breed. The Base population (one or more unknown parents) contained 4,709 animals. Only 53.03% and 52.98% had known sire and dam, respectively. Most animals were found in the Brazilian Northeast, but in recent years numbers have increased in São Paulo State. Generation interval in this breed was approximately 3.6 years. Most farms buy rams or semen which helps maintain low inbreeding levels, as well as using their own rams. There is a need to increase registration beyond Base animals and use pedigree to avoid crosses between related animals. Nevertheless, no immediate problems were seen for maintenance of genetic diversity within the Morada Nova sheep breed.