Estimating live weight of sheep of Guatemala by a simple formula

Abstract

A sample of 64 native ovines (50 females and 14 males) of different ages (from sucklings to very old individuals) belonging to different flocks, from different local communities of the Quetzaltenango Department in W Guatemala, were weighed and measured for thoracic girth (TG), ear length, cannon perimeter, face length and head length. Measurements were obtained by the same persons. Live weight (LW) was estimated using a linear model. Coefficient of determination (R2) values computed for LW versus TG were 0.871. It was concluded that thoracic girth is a useful tool in predicting weight of sheep from Guatemala for all ages. From this, the derived predictive equation for the live weight determination from thoracic girth, LW (kg) = TG0.735 is a quite simple, easy to remember formula, presenting a high coefficient of determination, and with no statistical differences between real and estimated weight values.