关键词: 理想蛋白水平, 仔猪, 生产性能, 蛋白质利用

Abstract: This single factorial designed experiment was conducted to investigate the effect of varying dietary ideal protein (IP) level on performance and protein utilization of early-weaned piglets. Eighty (6.5±0.5) kg, (21±1) d DLY weaning piglets were randomly allocated into five treatments (4 replicates per treatment, 4 piglets per replicate) and fed with five graded levels of IP diets respectively (14%, 17%, 20%, 23%, 26%). The ratios of TDLysT:DSAA:TDThr:TDTrp in five diets were kept the same (100:57:62:18), the ratios of other TDEAA to TDLys met or exceeded the recommended values in NRC(98), the proportion of TDLys to CP was 5% in each diets. The experimental results demonstrate that quadratic curve relationships occur between ADG, feeding efficiency and dietary IP levels (P<0.01). ADG and feeding efficiency are the highest in 20.2% and 22.3% IP diets respectively. Apparent nitrogen digestibility exhibits quadratic curve relationship with dietary IP levels (P<0.05) and the highest N digestibility occurs in 18.07% IP diet. Apparent nitrogen metabolism and ABV decrease linearly with the elevation of dietary IP levels (P<0.01). Urine N excretion changes with IP level quadratically, while total N excretion increases with dietary IP levels linearly (P<0.01). Based on the comprehensive consideration of performance, protein utilization and nitrogen excretion, the optimal IP level for early-weaned piglets is 21.3%.

Key words: ideal protein level, early-weaned piglet, performance, nutrient utilization