Effect of feeding levels on nutrient utilization and prediction of nutrient requirements for Indian goats

Nutrient requirements based on feeding trial on adult male goats (age ~ 2 years, live weight 30.6 kg) in 3 ×3 Latin square switchover design were determined. Group I was fed on a diet to fulfill the maintenance requirement as per NRC (1981), while groups II and III were offered diets with 25 and 50% extra allowance for DM, CP and TDN. The nutrient requirements were determined by multiple regression analysis from feed intake against N balances. The % increase in intake of nutrients (g/kg W^0.75) over NRC (1981) requirements in groups I, II and III was 6.8, 17.5, 33.1 for DM; 30.6, 52.2 and 76.3 for CP; -0.6, 33.1 and 67.4 for DCP and 15.5, 23.8 and 31.8 for TDN, respectively. As the level of feeding increased the digestibility of DM and CP were increased while those of OM, EE, ADF remained same (P>0.05). N-retained (g/d) was significantly higher (P<0.05) in group III than in group I. The nutrients requirements for CP, DCP and TDN for group I were 5.67, 3.22 and 38.14, in group II, 7.12, 4.57 and 45.21 and in group III, 8.38, 5.84 and 51.37, respectively at zero N balance when a covariate (CPD) was used in regression analysis (R²= 58.4% to 73%). Predicted requirements at higher planes of nutrition (groups II and III) were comparatively higher. The present study provide information regarding CP, DCP and TDN requirements of goats for maintenance at three levels of feeding.