Parâmetros genéticos de temperamento e resistência de bovinos da raça Nelore ao carrapato Boophilus microplus e validação do uso de marcadores moleculares na seleção para essas características / Genetic parameters of docility and resistance to the tick Boophilus microplus and validation of the use of genetic markers in selectin for those traits

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

The study on traits like docility and resistante to ticks aims to help selection os animals with better genotypes to those traits, to increase productivity, but also keep adptation of those animals to the environment of extensive production systems used in the Brazilian beef production. Those animals, adapted to thse environmental conditions, should also optimize costs and increase profitability of the whole system. Docility, or temperament is an important trait in beef cattle production. Wild or nervous animals are very reactive, and can be risky to handle, not only to cattleman, but also for them, causing wounds and a decrease of their carcasses or production. The tick infestiation, specially with the species Boophilus microplus, can cause important losses for beef industry, being considered an important problem for that production. The validation of the use of genetic markers in selection for traits linked to temperament and tick resistance, by the study of association of the genotypes and the phenotypes or estimated genetic values allows to understand those relationships and indicate the possible use of those markers in selection of those traits. The objectives of this study were to estimate genetic parameters and define gene and genotype frequencies of several polymorphisms of single basis DNA markers (SNPs) of traits linked to docility and tick resistance, besides developing different methodologies to measure tick resistance in Nellore beef cattle reared in a tropical area on southeastern Brazil. Heritability estimates varied, in general, from low to medium for all traits, but temperament, where the estimates were high. Several markers, originally discovered in Bos Taurus, showed polymorphism in the Nellore population studied. For several os the studied markers, it was possible to indicate the allele that was favorable to the traits. In this study, the evidences suggest that the use of genetic markers should speed up the response to selection for those traits in breeding programs.

ASSUNTO(S)

zebuínos animal behavior ectoparasites bos indicus comportamento animal gado de corte snp beef cattle bos indicus parasitas zebu cattle snp

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