日粮色氨酸水平对生长猪的氮利用效率、血浆类胰岛素生长因子-I、生长激素及胰岛素的影响

The Effects of Dietary Tryptophan on Nitrogen Utilization,Plasma Insulin-like Growth Factor-I (IGF-I), Growth Hormone (GH) and Insulin in Growing Pigs

本试验旨在研究日粮色氨酸水平对生长猪的氮利用率以及对血浆类胰岛素生长因子-I(IGF-I)、生长激素(GH)、胰岛素浓度的影响。试验以4头大白去势公猪作为试验动物,以色氨酸含量分别为1.2、1.7、2.2和2.7g/kg的4种日粮为试验处理,按照4×4拉丁方进行试验设计。结果表明,色氨酸水平对干物质消化率、有机物消化率和氮消化率没有显著性影响(P>0.05)。氮沉积和氮的生物学利用率随着日粮色氨酸水平由1.2提高到1.7、2.2和2.7g/kg而显著提高(P<0.05),但是试验处理1.7、2.2和2.7g/kg之间的氮沉积和氮的生物学价值没有显著差异(P>0.05)。不同处理之间的血浆IGF-I、GH和胰岛素浓度没有显著差异(P>0.05)。日粮色氨酸水平和血浆IGF-I、GH或胰岛素浓度之间以及氮沉积和血浆IGF-I、GH或胰岛素浓度之间均无显著的相关关系(P>0.05)。综合以上结果,日粮色氨酸水平对生长猪的氮沉积具有显著影响,而对血浆IGF-I、GH和胰岛素没有显著影响。

Four growing pigs and four diets that had graded levels of tryptophan, i.e. 1.2, 1.7, 2.2 and 2.7 g/kg as treatments, were used to study the effects of dietary tryptophan on nitrogen （N） utilization and plasma insulin-like growth factor- I （IGF-I）, growth hormone （GH） and insulin and the relationship between these parameters in growing pigs. The animals and the diets were allocated in a 4 × 4 Latin square design. The results showed that there was no significant difference in dry matter （DM） digestibility, organic matter （OM） digestibility and N digestibility between different treatments （P〉0.05）. The N retention and N biological value of diets were significantly increased when tryptophan level was increased from 1.2 to 1.7, 2.2 and 2.7 g/kg （P〈0.05）, but the difference in N retention and N biological value between treatments of 1.7, 2.2 and 2.7 g/kg tryptophan were not statistically significant （P〉0.05）. The results also showed that difference in plasma concentration of IGF-I, GH or insulin between different treatments was not significant （P〉0.05）. There were neither significant relationships between dietary tryptophan level and plasma concentration of IGF-I, GH or insulin, nor between nitrogen retention and plasma concentration of IGF-I, GH or insulin. Based on above results, there were significant differences in di- etary tryptophan levels and nitrogen utilization of growing pigs, but no significant differences in dietary tryptophan levels and plasma concentration of IGF-I, GH or insulin.