Estruturação genealógica para propostas de acasalamentos em rebanhos das raças Curraleiro Pé-Duro e Pantaneiro

Abstract

The brazilian bovine breeds Curraleiro Pé-Duro and Pantaneiro, inhabitants of Cerrado, Semi-árido and Pantanal are in the process of extinction, at risk of disappearing before their characteristics are adequately studied. The objective was perform the genealogical structure of breeds Curraleiro Pé-Duro and Pantaneiro, with a view to the conservation of animal genetic resources, in order to maintain the genetic variability within breeds, avoiding inbreeding, through proposals from matings based on genealogy. Samples of hair bulb from 1073 Curraleiro Pé-Duro cattle from nineteen herds and 290 Pantaneiros from four herds were analyzed. Amplification of 27 DNA microsatellites was performed by PCR. The average number of alleles per locus, allele frequency, heterozygosity expected and observed and polymorphic information content were calculated. For each animal an opinion of the affiliation control was issued. Large allelic variability was observed for the breeds, where the Curraleiro Pé-Duro presented an average of 8,70 alleles per loco and the Pantaneiro 6,70. The values of expected and observed heterozygosity were 0,713 and 0,653, respectively, for the Curraleiro Pé-Duro and 0,701 and 0,672 for Pantaneiro. The average value of polymorphic information content for the Curraleiro Pé-Duro was 0,671 and for the Pantaneiro 0,655. The probability of combined exclusion for the breeds was 0,99992. The mating lots were set at the minimum male:female ratio of 1:13 to the maximum of 1:26 for the Curraleiro Pé-Duro and 1:13 to 1:21 for the Pantaneiro, depending on the size of the herd. The paternity tests enabled the elaboration of reproductive programs for the herds, aiming to improve the genetic management of these populations, avoiding inbreeding. Both breeds showed great genetic variability inside of breeds, demonstrating that although they are in extinction have herds with a lot of genetic diversity.