Meta-análise da estimativa de herdabilidade do grau FAMACHA© e contagem de OPG em ovinos

Abstract

Sheep farming is an activity that has increasingly expanded in Brazil and around the world. However, sheep farmers face serious problems with resistance to antiparasitics, which generate economic and productive impacts. Therefore, it is important to research more about this resistance. Thus, with the significant increase in the production of scientific articles, many works are published covering the same subject, however, with different results and conclusions. Just as variations occur in the articles that address heritability estimates for the identification characteristics of resistance to antiparasitics, the FAMACHA© grade and the eggs count per grams of feces (EPG) in sheep. The objective was to estimate the combined heritability, through the meta-analysis methodology, for FAMACHA© grade and the EPG count in sheep. Through bibliographical research, 37 studies were selected, containing 38 values for the heritability estimate of the EPG characteristic, and 15 studies with 16 estimates for the FAMACHA© degree. Then, after tabulating the data, the analysis and synthesis of the information collected, interpretation and presentation of the results were carried out. The combined heritability values estimated by this work were 0.17 for EPG count and 0.20 for the FAMACHA© grade. So, both characteristics presented moderate h2 values. Therefore, when used in sheep selection, they tend to provide significant genetic progress.