Departamento de Producción Animal, Universidad Politécnica de Madrid, E.T.S. Ingenieros Agrónomos, 28040 Madrid, Spain.
J Anim Sci. 2010 Jan;88(1):170-80. doi: 10.2527/jas.2008-1698. Epub 2009 Sep 25.
The effect of dietary supplementation with 1% l-glutamine and a combination of 1% l-glutamine and 0.5% l-arginine on intestinal health was examined in weaned rabbits. A basal diet was formulated to meet nutrient recommendations. Another 2 diets were formulated by adding 1% (as-fed basis) Gln or a mixture of 1% (as-fed basis) Gln + 0.5% (as-fed basis) Arg (Gln-Arg) to the basal diet. In Exp. 1, a total of 357 rabbits were blocked by litter and assigned at random to the experimental diet to determine mortality (119 per diet) and growth performance (35 per diet; from weaning at 25 to 56 d of age). Rabbits were fed the experimental diets for a 2-wk period and thereafter received a commercial diet. Rabbits weaned at 25 d (blocked by litter and assigned at random to diets) were slaughtered at 35 d and used to determine apparent ileal digestibility of DM, CP, and AA (Exp. 2, a total of 60 rabbits), intestinal morphology, N-aminopeptidase and myeloperoxidase intestinal activity, the expression of PPARgamma at the ileum and kidney, serum immunoglobulin in healthy and sick rabbits (Exp. 3, a total of 24 rabbits), and ileal and cecal microbial composition by PCR-RFLP (Exp. 4, a total of 45 rabbits). Dietary treatment did not affect ADG, ADFI, or G:F, during the entire fattening period. Supplementation with Gln reduced mortality during the first 2 wk and the whole fattening period from 18.5 to 8.4% (P = 0.023) and from 31.9 to 20.2% (P = 0.039), respectively, whereas no effect was detected for Arg supplementation. Among all the variables studied, the reduction on mortality due to Gln was related to a reduced intestinal colonization (Eimeria lesions) and changes on microbial ecosystem in the ileum and cecum, reducing the frequency of detection of Clostridium spp. (from 86.7 to 33.3%, P = 0.003) at the ileum, and Helicobacter spp. at the ileum (from 86.7 to 46.7%, P = 0.003) and at the cecum (from 86.7 to 46.7, P = 0.028), whereas no effect was detected for Arg supplementation. In conclusion, 1% l-Gln supplementation to postweaned rabbit diets decreased fattening mortality and modified the intestinal microbiota (although no consistent effects were observed on mucosal histology or inflammatory and systemic immune response). Diets containing a combination of 1% Gln and 0.5% Arg were of little additional benefit.
本研究旨在探讨饲粮中添加 1% L-谷氨酰胺（Gln）和 Gln 与 0.5% L-精氨酸（Arg）混合物对断奶兔肠道健康的影响。试验采用基础饲粮，并在此基础上配制添加 1%（实际饲喂基础）Gln 或 Gln 与 Arg 混合物（实际饲喂基础，1%+0.5%）的 2 种试验饲粮。试验 1 选用 357 只 25 日龄断奶仔兔，按窝分为 3 个重复，每个重复 119 只，随机分为 3 个处理组，每组 35 个重复，每个重复 1 只。试验 1 为期 42 d，前 2 周仔兔饲喂试验饲粮，随后饲喂商品饲粮。25 日龄断奶仔兔（按窝分为 3 个重复，随机分为 3 个处理组）于 35 日龄屠宰，每组 60 只，用于测定日粮的表观回肠消化率（DM、CP 和 AA）、肠道形态、黏膜 N-氨基肽酶和髓过氧化物酶活性、回肠和肾脏过氧化物酶体增殖物激活受体γ（PPARγ）表达、健康和患病仔兔血清免疫球蛋白（试验 3），以及回肠和盲肠微生物组成（试验 4）。结果表明：1）饲粮添加 Gln 可降低断奶仔兔前 2 周和整个育肥期的死亡率，分别从 18.5%降至 8.4%（P=0.023）和从 31.9%降至 20.2%（P=0.039），但 Arg 对死亡率无显著影响。2）与对照组相比，饲粮添加 Gln 可降低肠道 Eimeria 病变和回肠及盲肠微生物区系的变化，减少 Clostridium 属（从 86.7%降至 33.3%，P=0.003）和 Helicobacter 属（从 86.7%降至 46.7%，P=0.003）在回肠及盲肠中的定植，这可能是降低断奶仔兔死亡率的原因。综上所述，饲粮添加 1% Gln 可降低断奶仔兔育肥死亡率，改善肠道微生物菌群（尽管黏膜组织学、炎症和系统性免疫反应未受显著影响），添加 Gln 与 Arg 混合物无额外益处。
