Impacto da restrição de dados na avaliação genética animal

• Autor(a) principal: Yamaki, Marcos
• Data de Publicação: 2009
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1299
• topic: Simulação; Índice de seleção; Parâmetros genéticos; Simulation; Selection index; Genetic parameters; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::GENETICA E MELHORAMENTO DOS ANIMAIS DOMESTICOS

Populations were simulated by information from a population A, with 59.028 Landrace swines, and a population B, 17.116 Pietrain swines, aiming to evaluate the impact of restrictions strategies on genetic evaluation of simulated and real populations. Simulated populations were generated by the pedigree and phenotypic means for age to reach 100 kg live weight, back fat thickness at 100 kg of live weight and feed conversion ratio, of their respective populations. On both type of populations, simulated and real, two situations were evaluated on three different restrictions, commonly used on animal genetic evaluations. The studied restrictions were: number of generations considered on the analysis, considering the last six and three generations of the populations, minimum offspring by boars, considering males with at least ten and 50 offspring and minimum observations considered on levels of fixed effect of contemporary group, considering at least six and three observations by level. Expected breeding values (EBV) from group of the selected animals, obtained by using complete data set, were compared to the EBV’s obtained on the various scenarios described on each type of restriction for simulated and real populations. The EBV’s of selected animals after restrictions were rescued from analysis of respective populations using the entire data set. Greater variations on heritabilities, and consequently on EBV’s, were observed that restriction that considered the last three generations on both populations, A and B, and this behavior was also observed on the real populations. The analysis restricting boars with less than 50 offspring caused the second bigger variation on B populations. The restriction of dataset to three generations is not indicated for genetic evaluations, on big and small populations, for causing huge variations on EBV’s and compromising the evaluations.