PREDICTION OF MONTHLY BODY WEIGHT FROM BODY MEASUREMENTS IN BEETAL GOATS REARED UNDER FIELD AND FARM CONDITIONS

The aim of the present study was to predict live body weight from several body measurements in Beetal goats at various ages. Data on live body weight and linear body measurements taken from Beetal goats were recorded from six private herds and two government farms of Punjab, Pakistan. Final data file contained 5011 observations of live body weight (LBW) and different body measurements i.e. whither height (WH), body length (BL), chest girth (CG), chest width (CW) and pin bone width (PW). The quantitative traits were recorded by hanging balance (for LBW) and tailor’s tape (for all others) from January 2016 to May 2017. The ages of animals were divided into thirty-seven classes with birth age class declared as 0, monthly age class 1 (1-30 days) and so on up to monthly age class 36 (1051-1080d). The overall birth and 36 month averages of LBW, WH, BL, CG, CW and PW were found 3.34 & 80.21(kg), 33.61 & 92.91, 25.11 & 84.86, 30.96 & 93.30, 8.88 & 26.21 and 4.69 & 14.00 (cm), respectively. All the body measurements showed highly significant effect on LBW of animals at 3 and 21 months of age (P ≤ 0.05). The CG was highly significantly related to LBW in all monthly age classes with the exception of 0, 1, 2 and 7 months (P ≤ 0.05). The PW had non-significant effect on LWB for all monthly age classes with the exception of 3, 4, 9, 10, 11, 21, 32 and 35 months. The WH had highly significant effect on LBW of animals in monthly age classes of 3, 7, 10, 11, 12, 14, 15, 16, 17, 20, 21 and 35. The BL in general showed significant effect on LBW up to 26 months of age. In agreement to regression results, CG had strong positive phenotypic correlation (0.921, P≤0.05) with LBW, followed by BL (0.875, P≤0.05), WH (0.864, P ≤ 0.05), CW (0.777, P ≤ 0.05) and PW (0.725 P ≤ 0.05). The value of R-squared of linear regression model is 0.85. In conclusion, CG, BL, WH, CW and PW may be used for predicting live body weight in Beetal goat in the order of priority. These body measurements may be combined in an index with appropriate weights to more accurately predict live body weight under field conditions. Considering precisely estimated genetic parameters for all these traits, the body measurement traits may also be used for indirect genetic selection for improved growth rate in Beetal goat.