Xu Ye Tong, Ma Xiao Kang, Wang Chun Lin, Yuan Ming Feng, Piao Xiang Shu
State Key Laboratory of Animal Nutrition, Ministry of Agriculture Feed Industry Centre, China Agricultural University, Beijing 100193, China.
Yunnan Most Fast Animal Husbandry Science and Technology Company, Yunnan 653100, China.
Asian-Australas J Anim Sci. 2018 Jan;31(1):106-115. doi: 10.5713/ajas.17.0148. Epub 2017 May 14.
The goal of this study was to investigate the effects of dietary standard ileal digestible (SID) valine:lysine ratios on performance, intestinal morphology, amino acids of liver and muscle, plasma indices and mRNA expression of branched-chain amino acid (BCAA) metabolism enzymes.
A total of 144 crossbred pigs (Duroc×Landrace×Large White) weaned at 28±4 days of age (8.79±0.02 kg body weight) were randomly allotted to 1 of 4 diets formulated to provide SID valine:lysine ratios of 50%, 60%, 70%, or 80%. Each diet was fed to 6 pens of pigs with 6 pigs per pen (3 gilts and 3 barrows) for 28 days.
Average daily gain increased quadratically (p<0.05), the villous height of the duodenum, jejunum and ileum increased linearly (p<0.05) as the SID valine:lysine ratio increased. The concentrations of plasma α-keto isovaleric and valine increased linearly (p<0.05), plasma aspartate, asparagine and cysteine decreased (p<0.05) as the SID valine:lysine ratio increased. An increase in SID lysine:valine levels increased mRNA expression levels of mitochondrial BCAA transaminase and branched-chain α-keto acid dehydrogenase in the longissimus dorsi muscle (p<0.05).
Using a quadratic model, a SID valine:lysine ratio of 68% was shown to maximize the growth of weaned pigs which is slightly higher than the level recommended by the National Research Council [6].
本研究旨在探讨日粮标准回肠可消化（SID）缬氨酸与赖氨酸比例对生长性能、肠道形态、肝脏和肌肉氨基酸水平、血浆指标以及支链氨基酸（BCAA）代谢酶mRNA表达的影响。
选取144头28±4日龄断奶（体重8.79±0.02 kg）的杜洛克×长白×大白三元杂交猪，随机分为4组，分别饲喂SID缬氨酸与赖氨酸比例为50%、60%、70%或80%的4种日粮。每种日粮饲喂6个猪栏，每栏6头猪（3头小母猪和3头小公猪），为期28天。
随着SID缬氨酸与赖氨酸比例的增加，平均日增重呈二次曲线增加（p<0.05），十二指肠、空肠和回肠的绒毛高度呈线性增加（p<0.05）。随着SID缬氨酸与赖氨酸比例的增加，血浆α-酮异戊酸和缬氨酸浓度呈线性增加（p<0.05），血浆天冬氨酸、天冬酰胺和半胱氨酸浓度降低（p<0.05）。随着SID赖氨酸与缬氨酸水平的增加，背最长肌中线粒体BCAA转氨酶和支链α-酮酸脱氢酶的mRNA表达水平增加（p<0.05）。
采用二次模型表明，SID缬氨酸与赖氨酸比例为68%时可使断奶仔猪生长性能最大化，略高于美国国家研究委员会推荐水平[6]。
