On-farm phenotypic characterization of indigenous Tswana sheep population in selected Districts of Southern Botswana

Abstract

This study aimed to phenotypically characterize indigenous Tswana sheep under its natural environment and develop prediction equations for body weight using linear body measurements in Kgatleng, Kweneng, Southern and South-East districts of Botswana. Multistage purposive sampling was used for selection of districts. Data on qualitative characters and quantitative measurements were made on 665 sheep stratified by dentition into four age categories (0PPI, 1PPI, 2PPI and ≥3PPI). Both qualitative and quantitative data were analyzed using Statistical Analysis System. Most Tswana sheep were characterized by plain coat color pattern with white dominating and plain white colors, short-fat tails with a straight tip, horizontal ears, no horns and wattles. District, sex and age had a significant influence on body weight and most linear body measurements. The highest correlation between body weight and heart girth for both sexes indicate that heart girth explained more variation than other measurements thus is the best variable for predicting body weight in both sexes. The best predicted body weight model for males is y=-64.15+1.28x and y=-53.47+1.14x for females where x and y are heart girth and body weight, respectively. This study reveals existence of diversity of sheep genetic resources across districts, indicating their potential response to selection. Key words: Body weight, characterization, morphometric traits, Tswana sheep.