Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, 644# Yuanda 2 Rd, Changsha, 410125, Hunan, China.
Hunan Co-Innovation Center of Animal Production Safety, Changsha, 410128, Hunan, China.
Amino Acids. 2017 Dec;49(12):2009-2014. doi: 10.1007/s00726-017-2440-3. Epub 2017 May 24.
L-Tryptophan (Trp) and some of its metabolites regulate the circadian rhythm in mammals. We aimed to investigate the effects of short-term supplementation of Trp in isocaloric meals on growth performance using the parameters of multiple blood biomarkers and free amino acids in growing pigs. A total of 32 Landrace × Yorkshire barrows with a mean body weight of 8.64 (±1.13) kg were randomly assigned to four groups and then fed with various concentrations of Trp diets daily. Our results showed that sequential supplementation of different concentrations of Trp in isocaloric meals decreased the feed:gain (F:G) ratio (P = 0.079) and plasma urea and albumin (P = 0.019), whereas the level of total protein did not. Among the essential and conditionally essential amino acids, the concentrations of histidine, isoleucine, proline, threonine, arginine, and valine in the plasma decreased (P < 0.05), whereas the concentrations of Trp, glycine, serine, and methionine increased (P < 0.01). In addition, concentrations of branched chain amino acids also significantly decreased (P = 0.004), while the rate of conversion of Trp to branched chain amino acids increased (P < 0.001). Taken together, we show that administration of a high concentration of Trp in breakfast with decreasing concentrations of Trp in lunch and dinner positively affected feed utilization and improved feed efficiency, at least in part, through the optimization of amino acid interconversions and nitrogen utilization.
色氨酸（Trp）及其一些代谢物调节哺乳动物的昼夜节律。我们旨在通过生长猪的多项血液生物标志物和游离氨基酸参数，研究在等热量膳食中短期补充色氨酸对生长性能的影响。共有 32 头平均体重为 8.64（±1.13）kg 的长白猪×约克夏公猪被随机分为四组，然后每天喂食不同浓度的 Trp 饮食。我们的结果表明，在等热量膳食中连续补充不同浓度的 Trp 会降低饲料：增重（F：G）比（P=0.079）和血浆尿素和白蛋白（P=0.019），而总蛋白水平没有。在必需和条件必需氨基酸中，血浆中组氨酸、异亮氨酸、脯氨酸、苏氨酸、精氨酸和缬氨酸的浓度降低（P<0.05），而色氨酸、甘氨酸、丝氨酸和蛋氨酸的浓度升高（P<0.01）。此外，支链氨基酸的浓度也显著降低（P=0.004），而色氨酸转化为支链氨基酸的速率增加（P<0.001）。综上所述，我们表明在早餐中给予高浓度的色氨酸，在午餐和晚餐中给予降低浓度的色氨酸，积极影响饲料利用，并通过优化氨基酸相互转化和氮利用，至少在一定程度上提高饲料效率。
