Prediction models for live body weight and body compactness of Criollo sheep in Huancavelica Region, Peru

Abstract

This study aimed to identify the phenotypic correlations between live weight (LW), zoometric characteristics, and indices in Criollo sheep to develop prediction equations for LW and body compactness. The independent variables included live weight (LW), body length (BL), withers height (WH), chest depth (CD), chest width (CW), chest circumference (CC), muscle circumference (MC), loin width (LW), and loin length (LL). Additionally, body volume (BV), body index (BI), and body compactness (BC) were determined based on zoometric measurements. The evaluations involved 111 male and female sheep aged between 4 and 6 years, data collection took 3 months, from March-May, 2023. The correlations between the characteristics and LW were positive and statistically significant, except for MC. Criollo sheep were classified as brachylines based on the BI value of 69.16±7.20. Substantial and strong correlations were found between BI, BC1, BC2, BC3, and live weight. Prediction equations were developed to estimate live weight using chest circumference, with the quadratic equation proving the most efficient. When body volume was considered a predictor, the cubic equation (R2=0.46) demonstrated better accuracy in predicting live weight. The multiple regression equation incorporating live weight and body length achieved a superior fit (R2=0.99) in predicting the body compactness of sheep. This equation is recommended for its accuracy, practicality, and ease of use.

Keywords

• Body volume, Characteristics, Characterization, Criollo sheep, Productive relationships, Zoometric índices