Estimating Body Weight of Cattle Using Linear Body Measurements
AbstractThe relationships between body weight (BW) and heart girth, body length and height at withers of 116 Indigenous, 72 Friesian, 95 Brahman, 88 Red Dane and 123 Crossbred cattle from 42 smallholder herds in Nharira-Lancashire, Zimbabwe, were investigated. The principal objective was to develop simple models that could be used to estimate BW. For 11 consecutive months, 4201 body weight records of 494 cattle were collected. Body weight was highly correlated (r ≥ 0.90) with body length, heart girth and height at withers but particularly so with heart girth (r = 0.96). This implies that heart girth alone can be used to develop a reliable prediction equation for BW. A general prediction equation for all the four classes of cattle, BW = 73.11 - 1.958 GTH + 0.01899GTH2 + 0.0000216GTH3 (R2 = 0.97), where BW represents BW and GTH, heart girth, was obtained using the backward elimination regression procedure. In addition, individual class of cattle-specific equations were developed for cows only, bulls only, oxen only and female calves/heifers. Tables of estimates of BW from heart girth obtained using the equations developed in this study are useful practical tools for farmers, researchers and rural development workers.
Zimbabwe Veterinary Journal (2002) 33; 15-21