ESTIMATION OF GOAT LIVE WEIGHT USING THE CREVAT FORMULA AND SIMPLE LINEAR REGRESSIONS

The objective of this study is to predict the body weight of 312 goats (175 females and 135 males) from the local population of different regions in eight wilayas (Souk Ahras, El-Tarf, Jijel, Sétif, Guelma, Bordj bou Arréridj, Ouargla, and Biskra) over the age of 2 using five body measurements. The total body length (LT), scapular-ischial length (SIL), height at withers (HG), width at hips (HW), circumference of the chest (TP) and the CREVAT formula to determine the best parameters for predicting live weight and to establish specific formulas. Body measurements were taken in centimeters, and body weight (BW) was determined in kilograms using a weighing scale. The results of the correlation coefficient were more marked with the chest circumference (HG) (r = 0.994) and the scapulo-ischial length (r = 0.969) than with the height at the withers (0.959). Whereas for the linear regressions of chest circumference (HG) and height at the withers, these proved to be the most accurate predictive equations for all the animals. Based on the CREVAT formula, the goats in the study have a much higher constant “x” (x = 85.30 ±38.29) than that of the other species (cattle, sheep and horses). The coefficient “x” of the males is slightly higher (86.33 ±31.72) than that of the females (84.49 ±42.80). However, the formula that is valid for the goats studied is: P = 85.30 X (TP)3.