Technical Options for Body Weight Estimation: Prediction of Body Weights of Indigenous Sheep Populations from Their Linear Body Measurements
Teweldemedhn Mekonnen
*
Tigray Agricultural Research Institute, Humera Begait Animals Research Center, Tigray, Ethiopia.
Medhanye Araya
Tigray Agricultural Research Institute, Mekelle Bee Research and Training Center, Tigray, Ethiopia.
Solomon Tesfahun
Tigray Agricultural Research Institute, Humera Begait Animals Research Center, Tigray, Ethiopia.
*Author to whom correspondence should be addressed.
Abstract
The field data collection was conducted before the war (before October 2020) in Tigray Regional State, Ethiopia. The objective of the study was to determine the relationships between the linear body traits (LBTs) and body weight of the indigenous sheep, and to develop regression equations for predicting live body weights of each population. Begait (173), Rutanna (151) and Arado (164) sheep of sample animals were randomly involved in the field data collection. Dentition was used to determine the age of the animals and were from one permanent pair of incisor up to four pairs of permanent incisors. The data were analyzed by Statistical Package for Social Sciences software. The indigenous sheep populations were kept under low input extensive production system. The overall mean direct field weighed live body weights of the Begait, Rutanna and Arado sheep populations were 40.4±0.49 Kg, 48.3±0.94 Kg and 28.3±0.29 Kg, respectively. The correlations (P<0.01) between LBTs and direct field weighed live body weights of the indigenous sheep revealed that the LBTs could be used as indirect selection traits and could also be used to predict the live body weights of the indigenous sheep in areas where weighing scale is not available by using different regression equations. Chest depth (ChD = 0.817) and chest girth (ChG = 0.880) in Begait, ChD (0.874) and ChG (0.913) in Rutanna, and ChD (0.705) and ChG (0.788) in Arado sheep were among the highly significantly (P<0.01) correlated LBTs with the body weights of the indigenous sheep populations. Except in male Rutanna, chest girth or chest circumference could be solely used to predict the live body weights of the indigenous sheep breeds. This characterization work revealed that the Rutanna sheep (a transboundary breed) could be primarily used for mutton production due to their large live body weights. Genetic characterization of the indigenous sheep populations should be conducted for the identification of economically important candidate genes of the populations.
Keywords: Body weight prediction, correlation, indigenous sheep, linear body traits, regression equation