Genetic parameters for body weight and morphometric traits in Santa Ines sheep using Bayesian inference

Abstract

The objective of this study was to estimate genetic parameters between body weight and morphometric traits to choose selection criteria to improve genetically the body weight and body conformation using Bayesian inference. Body weight, body length, chest girth, croup height, croup width, withers height, and body condition score of 645 Santa Ines meat sheep were used to estimate the genetic parameters in a multi-trait animal model with Bayesian approach. The heritability estimates ranged from 0.19 ± 0.05 to 0.32 ± 0.07 (croup width and body condition score respectively), which allow them to respond to genetic selection. The genetic correlations between body weight and morphometric traits were positive and ranged from 0.18 ± 0.17 to 0.98 ± 0.02. The genetic correlation between body weight and chest girth (0.98 ± 0.02) indicates that selection based on one trait will result in genetic gain for the other. The body weight is the main selection criterion to increase the meat production via genetic selection of the animals due to its moderate heritability and moderate to high genetic correlation with the other traits studied. However, if calibrated electronic scales are not available for the sheep producers, they can use the morphometric measurements to carry out the selection of animals to result in indirect genetic gains for body weight. If the breeders want to choose only one morphometric trait to indirectly improve the genetic body weight, chest girth is recommended due to its extremely high genetic correlation with body weight. The next step would be to develop an index that takes into account all the morphometric measurements to use it as indirect indicator of body weight.