饲粮净能水平对30～50kg生长猪生长性能的影响OA

This trial was conducted to investigate the effects of different dietary net energy(NE)levels on growth performance and nutrient digestibility of growing pigs weighing 30-50 kg.A total of 180 healthy cas-trated Duroc×Landrace×Yorkshire crossbred boars at 71 days of age with an initial body weight of(30.96±0.02)kg were selected.A single-factor experimental design was adopted,and the pigs were randomly assigned to 5 treatments based on uniform initial body weight,with 6 replicates per treatment and 6 pigs per replicate.The experimental diets were formulated to contain gradient NE levels of 9.46(Group A),9.71(Group B),9.96(Group C),10.21(Group D)and 10.46(Group E)MJ/kg,respectively.The results showed that Group A had the highest average daily feed intake(ADFI),which was significantly higher than that of Group C(P<0.05).ADFI increased gradu-ally with the elevation of dietary NE level;Group D exhibited the maximum ADFI and final average body weight.Group E had the lowest feed-to-gain ratio(F/G),which was significantly lower than Group A(P<0.05).Average daily gain(ADG)of growing pigs increased as dietary NE rose,and the relative digestibility of net energy and crude protein showed an overall upward trend.Dietary NE level had no significant effects on the apparent total tract digest-ibility of dry matter,calcium and total phosphorus(P>0.05).Dietary NE exerted a significant influence on crude protein digestibility(P<0.05),with Group D obtaining the highest apparent digestibility of crude pro-tein.In conclusion,under the conditions of this experiment,the optimal dietary NE level for growing pigs of 30-50 kg body weight is 10.46 MJ/kg,which supports the best growth performance.