| This trial was conducted to predict the Net energy (NE) values of the corn, soybean meal, rapeseed meal, cottonseed meal, wheat bran, and rice bran, Using the NE predictive model by determining the DE and the ME of the feeds, Feeding experiment used different ratio of feeds to formulated 4 different diets of same NE and TDLys levels, the NE and TDLys levels was referred to Chen Liu (2009). So to assess the accuracy of the NE values of feeds and NE requirement of growing pigs by the investigation of the growth performance, nitrogen utilization and energy utilization.Experiment 1 prediction the NE of corn, soybean meal, rapeseed meal, cottonseed meal, wheat bran and rice branThe metabolizable tria measured the DE,ME of feeds by the method of substitution, Using the Latin square design(2×2,2×2,3×3),Every stage was 6 DLY growing pigs, All pigs were 30.17±1.86 kg in the initial stage, one pig a duplicate, the period was 3 stages of totally 7 turns, the Laboratory analyzed the CP, EE, ST and ADF, The NE values was calculated by Noblet's predictive model, mainly accorded to the DE,ME and combine with the conventional nutrient to predict the NE values. The results showed that:the NE values of corn, soybean meal, rapeseed meal, cottonseed meal, wheat bran and rice bran were 12.50,9.14,5.54,4.84,6.85 and 11.58 MJ/kg DM.Experiment 2 Effects of different diets on the growth performance, nitrogen and energy utilizationFeeding experiment were total 30 (20.54±0.32 kg) DLY growing pigs, which were randomly assigned to 5 treatments with 6 replicates and 1 pig with each pen,which were soybean meal treatment (The control group)and 12%rapeseed meal, 12% cottonseed meal,20% wheat bran,20% rice bran treatment(4 experiment treatments),The diets of all treatments were equal NE and TDLys. The feeding trial lasted for 42 days. All treatments chosed 4 pigs to measure the N utilization and energy utilization trial when the feeding experiments was over, the adaptation and formal period was 2 and 6 days respectively. Feeding experiment showed that ADG of all treatments were no significantly difference compared with soybean meal treatment (The control group) (P>0.05). The ADFI and F/G of 20% rice bran treatment were respectively a little lower (P<0.05) and significant lower (P＜O.01) than the soybean meal treatment, There were no differences (P>0.05) among other treatments.N and energy utilization trial showed that:Nitrogen intake, Nitrogen retention, Nitrogen biological value (N-BV)of all treatments was no significantly difference compared with the control group. Only Nitrogen intake of 20% rice bran treatment was significantly lower than the 12% cottonseed meal group (P<0.05),N-BV of 12% rapeseed meal was higher than 20% wheat bran group (P<0.01),20% rice bran group (P<0.05) and 20% cottonseed meal group (P＜0.05).NE values and NE/ME of all treatments were no significantly difference compared with s the control group (P>0.05). The 20% rice bran and 20% wheat bran group was a slightly higher than the soybean meal, rapeseed meal and cottonseed meal group in the NE and NE/ME, but the difference was little (P>0.05).Considering the growth performance, nitrogen and energy utilization of all treatments, It could be conclued that the regression equations of Noblet(1994) could accurately predict the NE values of feeds; When the TDLys was 0.92% (DM), dietary NE level of 11.26 MJ/kg DM could meet the energy requirement of the DLY growing pigs. |
