Department of Animal Science, School of Environmental and Rural Sciences, University of New England, Armidale, NSW 2351, Australia.
South Australian Research and Development Institute, Roseworthy Campus, University of Adelaide, Roseworthy, SA 5371, Australia.
Poult Sci. 2018 Apr 1;97(4):1334-1341. doi: 10.3382/ps/pex444.
Necrotic enteritis (NE) causes significant economic losses in the broiler chicken industry, especially in birds raised without in-feed antibiotics. L-glutamine (Gln) is an amino acid that may compensate for metabolic losses from infection and improve the intestinal development. This study investigated the effects of dietary Gln (10 g/kg) supplementation on growth performance, intestinal lesions, jejunum morphology, and serum biochemical indices of broiler chickens during NE challenge. The study employed a factorial arrangement of treatments with factors: NE challenge, no or yes; dietary Gln inclusion, 0 g/kg in starter (S), d 0 to 10, grower (G) d 10 to 24, and finisher (F) d 24 to 35; 10 g/kg in S, G, F, or 10 g/kg in S, G only. Each treatment was replicated in 6 floor pens with 17 birds per pen as the experimental unit for performance and 2 birds for other measurements. Challenge significantly reduced bird performance, increased incidence of intestinal lesions, and affected intestinal development and serum biochemical indices. Regardless of challenge, Gln supplementation increased gain (P < 0.05), feed intake (P < 0.05), and decreased FCR (P < 0.05) on d 24. On d 35, Gln improved gain (P < 0.05) and FCR (P < 0.001) whereas withdrawing Gln from finisher tended to diminish the beneficial effect on weight gain but not FCR. Dietary Gln reduced lesion scores in the jejunum (P < 0.01) and ileum (P < 0.01) in challenged birds. On d 16, Gln increased villus height to crypt depth ratio in unchallenged birds (P < 0.05) and reduced crypt depth of challenged birds on d 24 (P < 0.05). Regardless of challenge, supplementation with Gln reduced crypt depth on d 16 (P < 0.05), and increased villus height (P < 0.01) and the villus height to crypt depth ratio (P < 0.001) on d 24. Dietary Gln lowered serum uric acid level regardless of challenge (P < 0.05). The current study indicates that dietary Gln alleviates adverse effects of NE and may be useful in antibiotic-free diets.
坏死性肠炎（NE）给肉鸡产业造成了巨大的经济损失，尤其是在不使用饲料抗生素饲养的禽类中。L-谷氨酰胺（Gln）是一种氨基酸，它可能会弥补感染引起的代谢损失，并改善肠道发育。本研究探讨了日粮 Gln（10g/kg）补充对 NE 攻毒期间肉鸡生长性能、肠道病变、空肠形态和血清生化指标的影响。本研究采用了双因子处理设计，因子包括：NE 攻毒和非攻毒；日粮 Gln 添加，0g/kg 于起始期（S），d0 到 10，生长期（G），d10 到 24，育肥期（F），d24 到 35；10g/kg 于 S、G、F 期或 10g/kg 于 S、G 期。每个处理在 6 个地面鸡舍中进行重复，每个鸡舍有 17 只鸡作为性能实验单位，2 只鸡用于其他测量。攻毒显著降低了鸡的生产性能，增加了肠道病变的发生率，并影响了肠道发育和血清生化指标。无论是否攻毒，Gln 补充都增加了 d24 的增重（P<0.05）、采食量（P<0.05）和降低了 FCR（P<0.05）。在 d35，Gln 提高了增重（P<0.05）和 FCR（P<0.001），而在育肥期停止 Gln 补充则可能减弱对增重的有益影响，但对 FCR 没有影响。日粮 Gln 降低了攻毒鸡空肠（P<0.01）和回肠（P<0.01）的病变评分。在 d16，Gln 增加了未攻毒鸡的绒毛高度与隐窝深度比值（P<0.05），并降低了攻毒鸡的隐窝深度（P<0.05）。无论是否攻毒，补充 Gln 都降低了 d16 的隐窝深度（P<0.05），增加了 d24 的绒毛高度（P<0.01）和绒毛高度与隐窝深度比值（P<0.001）。无论是否攻毒，日粮 Gln 都降低了血清尿酸水平（P<0.05）。本研究表明，日粮 Gln 减轻了 NE 的不利影响，在无抗生素日粮中可能有用。
