Meta-analysis of genetic parameters for economic traits in buffaloes

•A meta-analysis with 117 articles was carried out to estimate genetic parameters.•Heritabilities for 27 economics traits were estimated.•Genetic correlations for 34 pairs of traits were estimated.•A study of the heterogeneity of the articles was also carried out.•Combined estimates of the genetic parameters can be used under various conditions. Reliable estimates of genetic parameters for economic traits in buffaloes can be achieved through a meta-analysis that brings together several studies and accounts for the variation among them. This study aimed to perform a meta-analysis for 27 traits, including growth, reproduction, milk production and quality, and mastitis resistance, to estimate both heritability and genetic correlation parameters. A random model was used in the meta-analysis, where the factor “study” was adjusted as a random effect. The systematic review found 117 articles, including 387 estimates of heritability and 287 estimates of genetic correlations. A quality control of theses estimates was carried out, using the relative standard error (RSE) and both publication bias and heterogeneity tests. The mean of RSE for estimates of heritability were 13.96, 16.66, 11.33, and 11.42, for growth, reproduction, milk production, and milk quality, respectively. For genetic correlations, RSE ranged from 0.88 to 24.08. All estimates of heritability and genetic correlations showed no evidence of publication bias effect. The heterogeneity index (I²) for the heritability estimates ranged from 0 to 93.5, while for the genetic correlations ranged from 0 to 99.1. The weighted averages of heritabilities ranged from 0.2344 to 0.3811 for growth traits, 0.1134 to 0.2069 for reproductive traits, 0.1058 to 0.3130 for milk production traits, 0.1651 to 0.2751 for milk quality traits, and 0.2075 for somatic cell score. Most genetic correlations were positive, ranging from 0.1342 to 0.9884, but some correlations were negative such as milk yield x fat percentage (-0.2103) and milk yield x protein percentage (-0.1967). The combined estimates found in this meta-analysis showed that the traits evaluated have sufficient genetic variation to be included in buffalo selection programs. Furthermore, these genetic parameters are now an option for use in populations that do not yet have data control that allows to accurately estimate the parameters analyzed here.