Meta-analysis of genetic parameters for economic traits in sheep

摘要

Very diversified studies estimated genetic parameters in sheep, and reliable estimates that account for the variation between articles can be achieved through a meta-analysis. This study proposed to carry out a metaanalysis to obtain estimates of heritability and genetic correlations for 35 traits, including growth, reproductive, resistance to parasites, wool, and carcass related traits. A total of 191 articles, 505 heritability coefficients, and 356 genetic correlations were evaluated using a random model. The meta-analysis estimated heritability ranging from 0.1213 to 0.3912 for growth traits, from 0.0398 to 0.3047 for reproductive traits, 0.1724 to 0.2582 for resistance to nematodes traits, 0.3616 to 0.5808 for wool traits, and from 0.2063 to 0.3299 for carcass traits. The estimates of genetic correlations were mainly positive and ranged from 0.2500 to 0.9665, except for eggs per gram of feces with body weight (-0.18) and with hematocrit (-0.48). The genetic parameters estimated in the present study can be used in breeding programs under the most different environmental conditions, as they were obtained through many studies with different situations. Thus, these results can support the development of sheep breeding programs, especially in developing and underdeveloped countries, where sheep farming is an important agricultural activity.