限饲和自由采食条件下色氨酸对断奶仔猪血清IGF-1浓度的影响

IGF-1是动物出生后生长调节的重要因子,试验采用2×3因子试验设计,研究了饲喂方式(自由采食和限饲)和日粮色氨酸水平(0.12%、0.19%或0.26%)对仔猪血清IGF-1水平的影响,旨在探讨色氨酸对仔猪生长的调节途径。试验选用48头28日龄断奶、初始体重为(8.6±0.13)kg的二元杂交(长白×大白)阉公猪,按照随机区组的原则分成6个处理,每个处理8个重复。试验第10天,仔猪空腹12h,采血,制备血清,测定IGF-1浓度。结果表明:色氨酸具有改善仔猪生长性能、促进血清IGF-1浓度上升(P<0.01)的作用,饲喂方式和日粮色氨酸水平对血清IGF-1有互作效应(P<0.01),这表明色氨酸促进仔猪生长可能与血液中IGF-1水平升高有关。

Effect of Dietary Tryptophan Levels on Serum IGF-1 in Limited and Ad lib Fed Weaned Piglets

This study was designed to investigate the effect of dietary tryptophan on serum IGF-1 levels in limited and ad lib fed weanling piglets.48 crossbred pigs(Landrace × Large white) weaned at 28 d(8.60 ± 0.13 kg BW) were randomly allotted to 6 treatments with 8 replicates.Three diets were fed,with tryptophan concentrations as 0.12%,0.19%,and 0.26%.Ad lib fed pigs accessed to diet freely,and pigs in the limited fed treatment were fed by the volume weight of 8% BW0.75.On d 10 of the experiment,blood samples were collected by jugular vein to determine serum IGF-1 after 12 h fasting.The results showed that the adequate of dietary tryptophan per se induced higher serum IGF-1,average daily gain(ADG),average daily intake(ADFI) and improved the feed conversion rate(FCR) as well(P < 0.01).The interaction of tryptophan and feeding system was significant for serum IGF-1(P < 0.01),but not for growth performance of piglets.It impiled that dietary tryptophan might enhance growth by the regulation of serum IGF-1 in weaned pigs.