Study of genetic divergence among four broilers breeder lines using multivariate analysis

The performance of two broiler breeder lines, developed by Federal university of Vicosa - UFV (M I and F I) was tested against two mainly trade mark lines (C I and C2), using methods of multivariate analysis for the evaluation of the genetic divergence. Four important economic traits were evaluated: age at sexual maturity (IMS), egg number (NO). average egg weight (PO) and body weight (PM), during three periods of the productive life of the birds: initial (25(th) to 32(nd) week of age). medium (48(th) to 56(th) week of age) and total (25th to 62(nd) week of age). The study of the genetic divergence among the lines was made by means of multi variate variance analysis, cluster analysis using the generalized distance of Mahalanobis and the method of optimization of Tocher, and the analysis by canonical variables. The cluster analysis of the traits in the initial and medium periods ( grouped the four genotypes in two groups, the first was formed by the trademark lines and the second by the genotypes of UFV. In the total period, two groups were formed, the first one by the C1, F1 and M1 genetic groups and the second by C2. In the analysis by canonical variables, it was observed that the first two canonical Variables accounted for more than 92% of the total variation in the three periods. The traits that Contributed the most to the genetic divergence were average egg weight and body weight.