瘤胃保护性精氨酸及N-氨甲酰谷氨酸对细毛羊肠道黏膜蛋白质合成率的影响

摘要

本试验旨在探讨不同水平瘤胃保护性精氨酸(Arg)及N-氨甲酰谷氨酸(NCG)对细毛羊肠黏膜蛋白质合成率的影响.选用15只体况良好,平均体重为(25.00±3.39) kg的5月龄半同胞羯鄂尔多斯细毛羊断奶羔羊随机分成5组,分别为基础饲粮组(1组,对照组)、基础饲粮+0.15 g/d NCG组(2组)、基础饲粮+0.20 g/d NCG组(3组)、基础饲粮+1.50 g/d Arg组(4组)、基础饲粮+ 2.00 g/d Arg组(5组).进行45 d饲喂以后,试验羊空腹12 h后一次性大剂量灌注L-苯丙氨酸,90 min后采集十二指肠和空肠黏膜,检测小肠黏膜蛋白质合成率.结果表明:试验组的十二指肠与空肠黏膜的蛋白质合成率显著高于对照组(P＜0.05).在各试验组中,3组、4组、5组同1组相比提高幅度较大,其中4组显著高于其他试验组(P＜0.05),而3组和5组间差异不显著(P＞0.05).结果提示,添加不同水平的瘤胃保护性Arg及NCG对肠道黏膜蛋白质合成率具有提高作用,分别以1.50 g/d Arg和0.20 g/d NCG 2个剂量较好.%This study was conducted to investigate the effects of dietary rumen protected arginine (Arg) and N-carbamylglutamic acid (NCG) on protein synthesis rate in intestinal mucosa of fine-wool sheep. Fifteen weaner borwn Ordos fine-wool lambs [aged 5 months, average body weight was (25. 00 ±3. 39) kg] were randomly divided into five groups, and lambs were fed a basal diet (group 1,control group) , the basal diet + 0.15 g/d NCG (group 2) , the basal diet + 0. 20 g/d NCG (group 3) , the basal diet + 1. 50 g/d Arg (group 4) and the basal diet + 2. 00 g/d Arg (group 5) , respectively. The feeding lasted for 45 d. After 12 h fasting, lambs were injected a flooding-dose of L-phenylalanine, and then the duodenal mucosa and jejunum mucosa samples were collected after 90 min injection to measure the protein synthesis rate. The results showed that the protein synthesis rate in duodenal mucosa and jejunum mucosa in experimental groups was all higher than that in the control group (P <0. 05). Compared with group 1, the protein synthesis rate in groups 3 , 4 and 5 was increased more obviously, and group 4 was significantly higher than the other experimental groups ( P < 0. 05) , while there was no significant difference between group 3 and group 5 (P >0. 05). These results indicate that dietary rumen protected Arg and NCG can increase the protein synthesis rate of intestinal mucosa, and the optimal levels are 1. 50 g/d Arg and 0. 20 g/d NCG, respectively. [ Chinese Journal of Animal Nutrition, 2012, 24(11) :2141-2147]