Análise genética da produção de leite de ovelhas em um programa de cruzamento absorvente em direção à raça Lacaune

Abstract

This study aimed to carry out genetic analysis of the sheep milk production in an absorbent breeding program towards the Lacaune breed. The database comprised 168 sheep with lactation information and 33 players, was set up with genealogy information, lactation order, season of birth, month of birth date of birth, number of lambs born, medium weight born lamb (PM) , milk production at the peak ( 0b ), decrease in production after the peak ( 1b ) and total production (PROD). The estimation of variance components were performed using animal model, through MTGSAM program. Were performed univariate analyzes and tetracarater. Possession of variance components were possible to estimate heritability, genetic and phenotypic correlations, fashion, credibility interval and region can pitch for the features. The heritability found in univariate analysis were found heritability were 0.59; 0.35; 0.53 and 0.61, for PM, 0b , and PROD respectively. In tetracarater analysis were 0.50, 0.28, 0.02 and 0.60 for PM, 0b and PROD respectively. Genetic and phenotypic correlations respectively, between PM and 0b characteristics was 0.64 and 0.86; PM and 1b 0.61 and -0.17; 0b and 0.50 and -0.1; PROD and PM 0.03 and 0.07; 0b and PROD 0.04 and 0.05; PROD and 1b 0.17 and -0,12. It was concluded that the best selection criteria to be adopted on the characteristics evaluated for this population is based on the heritability of total milk production. Once the screen for direct feature, the genetic gain is greater. But it is necessary, constant studies on population characteristics , as they are dependent and constantly influenced by the environment.