Maintenance requirement and the net energy value of different diets for growth in pigs

Abstract An experiment was performed with 36 growing pigs (20–90 kg) to study the maintenance requirement. The results show that maintenance values varying from 325 to 375 kJ kg −1 live weight 0.75 are almost equally good as the influence on the error term is negligible, but the best fit was obtained with 351 kJ kg −0.75 . Digestibility experiments with ileo-caecal cannulated pigs indicated that level of feed intake had almost no influence on the proportion of digested energy disappearing in the caecum-colon. The data from all nitrogen balance and slaughter investigations performed sofar (1104 digestibility and nitrogen balances, 36 initial 20-kg-pigs, 288 90-kg-pigs) were pooled and analysed statistically. A regression analysis indicated that the maintenance requirement was 336 kJ NE kg −1 live weight 0.75 . For further calculations a maintenance requirement of 340 kJ kg −0.75 (618 kJ kg −0.6 ) was assumed. The contribution of digestible nutrients to ME are elucidated by the equation (ME adjusted to 50% protein deposition) ME (kJ) = 10 + 20.5X 1 + 36.7X 2 + 14.7X 3 + 17.3X 4 , (N=288) , s b 0.4 0.6 0.8 0.2 , t b 47.9 56.7 19.1 69.0 , CV =0.8 R 2 = 0.99 where X 1 , X 2 , X 3 , and X 4 are g digestible crude protein, crude fat, crude fibre and NFE, respectively. The utilization of ME was highly influenced by energy concentration as shown by the equation NE,MJ kg −1 DM = 0.81 ME, MJ kg kg −1 DM −2.20 , (N=288) , s b 0.02 , t b 45.9 CV =3.6, r 2 = 0.95