PDF(Pubmed)
Abstract：
Tryptophan plays an important role in the pig industry but has the potential to improve performance in the poultry industry. The purpose of this study was to examine the effects of tryptophan supplementation in diets with different protein levels on the feed intake, average daily gain (ADG), and feed conversion ratio (F/G) of broilers. A total of 180 twenty-one-day-old broilers (half male and half female) were weighed and randomly allocated to twelve groups, with six male and six female groups. Each group consisted of 15 broilers. The broilers were fed low- (17.2%), medium- (19.2%), or high- (21.2%) protein diets with or without extra tryptophan (up to 0.25%) during the 28-day experiment. Food intake and body weight were measured weekly during the trial period. Male broilers fed a medium-protein diet containing more tryptophan showed a lower F/G. In the low-protein diet groups, additional tryptophan caused a significant reduction in the feed intake of female broilers during the first two weeks. Moreover, the serum GLP-1, cholesterol, and bile acid levels, as well as the expression of FXR mRNA in the ileum, were significantly increased. Additionally, the FXR mRNA in the hypothalamus and the GCG and GLP-1R mRNAs in the ileum tended to increase in these broilers. In summary, the tryptophan concentration in the diet can influence the feed intake and metabolism of broilers. Under a standard diet, an appropriate amount of tryptophan is beneficial to the F/G of male broilers, while under a low-protein diet, tryptophan supplementation may cause a short-term reduction in the feed intake of female broilers by increasing serum GLP-1 and bile acid signals.
摘要：
色氨酸在养猪业中起着重要作用，但有可能提高家禽业的绩效。这项研究的目的是研究在不同蛋白质水平的日粮中添加色氨酸对采食量的影响。平均日增益（ADG），和肉鸡的饲料转化率(F/G)。共称量180只21日龄肉鸡(半雄半母),随机分配到12组,有六个男性和六个女性群体。每组由15只肉鸡组成。肉鸡饲喂低(17.2%)，中等-（19.2%），或高（21.2％）蛋白质饮食，有或没有额外的色氨酸（高达0.25％）在28天的实验。在试验期间每周测量食物摄入量和体重。饲喂含有更多色氨酸的中等蛋白质饮食的雄性肉鸡显示较低的F/G。在低蛋白饮食组中，在头两周内，额外的色氨酸导致雌性肉鸡的采食量显着减少。此外，血清GLP-1，胆固醇，和胆汁酸水平，以及FXRmRNA在回肠中的表达，显着增加。此外,在这些肉鸡中，下丘脑中的FXRmRNA和回肠中的GCG和GLP-1RmRNA趋于增加。总之,日粮中色氨酸浓度会影响肉鸡的采食量和代谢。在标准饮食下，适量的色氨酸有利于雄性肉鸡的F/G，在低蛋白饮食下，补充色氨酸可能会通过增加血清GLP-1和胆汁酸信号而导致雌性肉鸡的采食量短期减少。
