本试验旨在研究20~50 kg川藏黑猪的能量代谢与沉积规律。试验一：选择体重接近[（20.17±3.46）kg]的川藏黑猪配套系商品猪64头，预试7 d后屠宰4头猪测定胴体成分；其余试验猪按公母随机分成5个组，每个组4个重复，每个重复3头，各重复单圈饲养，自由采食消化能（DE）水平分别为13.79、13.37、12.96、12.54和12.12 MJ/kg的饲粮。试验猪体重达50 kg时，结束试验一，测定平均日采食量、平均日增重和料重比，并在各组选择1头猪屠宰测定胴体成分。试验二：选择试验一中15头体重接近[（48.34±4.07）kg]的公猪，随机分成5个组，每个组3个重复，每个重复1头，单独饲养于代谢笼，分别采食上述5种DE水平的饲粮，进行消化代谢试验。预试期3 d，正试期4 d。采用析因法建立能量需要量预测模型。结果表明：饲粮DE水平影响了20~50 kg川藏黑猪的平均日采食量、平均日增重和料重比；饲粮DE转化为代谢能（ME）效率（ME/DE）为97.26%~98.10%，ME用于沉积产品能的效率（DED/ME）平均值为41.71%；此阶段川藏黑猪维持需要ME平均值为0.49 MJ/W^0.75或0.85 MJ/W^0.60（按DE计为0.50 MJ/W^0.75或0.87 MJ/W^0.60），增重需要DE和ME平均值分别为18.91和18.47 MJ/kg。由此得出，20~50 kg阶段川藏黑猪能量需要模型为：DE（MJ/d）=0.504 W^0.75+18.91ΔW或DE（MJ/d）=0.867 W^0.60+18.91ΔW；ME（MJ/d）=0.492 W^0.75+18.47ΔW或ME（MJ/d）=0.847 W^0.60+18.47ΔW。

This experiment was conducted to investigate the regularity of energy metabolism and deposition of 20 to 50 kg Chuanzang black pigs. In the experiment one, fifteen Chuanzang black pigs at the body weight of (20.17±3.46) kg were selected, 4 pigs were killed to measure carcass composition after 5 days adaptation period, others were randomly divided to 5 groups based on sex (4 replicates per group and 3 pigs per replicate), pigs in the same replicate were fed in the same pen, pigs in the 5 groups were fed the diets which digestible energy (DE) levels were 13.79, 13.37, 12.96, 12.54 and 12.12 MJ/kg, respectively, and the average daily feed intake (ADFI), average daily gain (ADG) and feed to gain (F/G) were measured. Experiment one was finished when the weight of pigs reached about 50 kg, then one pig chosen in each replicate was killed to measure carcass composition. In the experiment two, fifteen barrows at body weight of (48.34±4.07) kg come from experiment one were randomly divided to 5 groups (3 replicates per group and 1 pig per replicate), each pig was fed in a metabolic cage, pigs in the 5 groups were fed the diets as same as the experiment one, the metabolic experiment contained 3 days adaptation period and 4 days test period. The energy requirement model was built by the factorial method. The results showed as follows:dietary DE level affected the ADFI, ADG and F/G of 20 to 50 kg Chuanzang black pigs. The conversion efficiency of DE transformed metabolizable energy (ME) (ME/DE) was 97.26% to 98.10%, the mean value of deposition efficiency of ME (DED/ME) was 41.71%; the mean value of ME for maintenance requirement was 0.49 MJ/W^0.75 or 0.85 MJ/W^0.60 (DE for maintenance requirement was 0.50 MJ/W^0.75 or 0.87 MJ/W^0.60),the requirements of ME and DE of weight gain were 18.91 and 18.47 MJ/kg, respectively. It is concluded that the energy requirement model is set up as:DE(MJ/d)=0.504 W^0.75+18.91ΔW or DE(MJ/d)=0.867 W^0.60+18.91ΔW;ME(MJ/d)=0.492 W^0.75+18.47ΔW or ME(MJ/d)=0.847 W^0.60+18.47ΔW.