Wang Chunping, Shang Lijun, Guo Qiuping, Duan Yehui, Han Mengmeng, Li Fengna, Yin Yulong, Qiao Shiyan
State Key Laboratory of Animal Nutrition, Ministry of Agriculture Feed Industry Centre, China Agricultural University, Beijing 100193, China.
Beijing Bio-feed Additives Key Laboratory, Beijing 100193, China.
Anim Nutr. 2022 Jun 28;10:412-418. doi: 10.1016/j.aninu.2022.04.012. eCollection 2022 Sep.
The aim of this study was as follows: 1) to investigate the effects of graded levels of N-carbamylglutamate (NCG) on performance, blood biochemical indexes, carcass traits and related indicators in growing-finishing pigs, and 2) to determine the optimal supplemental level. The toxicity of high-dose (much higher than recommended levels) NCG was assessed by routine blood tests and blood biochemical and histopathologic examinations of the heart, liver, spleen, lung, kidney and stomach. One hundred and forty-four growing-finishing pigs (Duroc × Large White × Landrace, 32.24 ± 1.03 kg) were used in a 74-d experiment and each treatment was replicated 6 times with 4 pigs (2 barrows and 2 gilts) per replicate. The dietary treatments were a corn-soybean meal basal diet supplemented with 0% (control), 0.05%, 0.1%, 0.15%, 0.2% or 1% NCG. The first 5 groups were used to explore the optimal supplemental level of NCG, while the control, 0.1% and 1% NCG groups were used to explore the safety of high-dose NCG. Compared with the normal control group, the final body weight and average daily gain tended to be higher in the 0.1% group ( = 0.08), the lean percentage tended to be higher in the 0.05% group ( = 0.07), the levels of free amino acids in the blood significantly increased in the 0.1% group ( < 0.05), both 0.1% and 0.15% NCG supplementation increased the levels of nitric oxide (NO) in serum ( = 0.07) and muscle growth- and lipid metabolism-related gene expression ( < 0.05) and NCG supplementation improved C18:1N9C monounsaturated fatty acids (MUFA) in a dose-dependent manner ( = 0.08). In addition, routine blood tests, blood biochemical indexes and histopathological examination revealed no abnormalities. Overall, increasing the levels of NCG did not linearly improve the above indicators; the 0.1% dose showed the best effect, and a high dose (1%) did not pose a toxicity risk.
1）研究不同水平的N-氨甲酰谷氨酸（NCG）对生长育肥猪生产性能、血液生化指标、胴体性状及相关指标的影响；2）确定最佳添加水平。通过常规血液检测以及对心脏、肝脏、脾脏、肺、肾脏和胃进行血液生化和组织病理学检查，评估高剂量（远高于推荐水平）NCG的毒性。选用144头生长育肥猪（杜洛克×大白×长白，体重32.24±1.03千克）进行为期74天的试验，每个处理重复6次，每次重复4头猪（2头公猪和2头母猪）。日粮处理为在玉米-豆粕基础日粮中分别添加0%（对照组）、0.05%、0.1%、0.15%、0.2%或1%的NCG。前5组用于探索NCG的最佳添加水平，而对照组、0.1%和1% NCG组用于探索高剂量NCG的安全性。与正常对照组相比，0.1%组的末体重和平均日增重有升高趋势（P = 0.08），0.05%组的瘦肉率有升高趋势（P = 0.07），0.1%组血液中游离氨基酸水平显著升高（P < 0.05），添加0.1%和0.15% NCG均提高了血清中一氧化氮（NO）水平（P = 0.07）以及肌肉生长和脂质代谢相关基因表达（P < 0.05），且NCG添加量呈剂量依赖性提高了C18:1N9C单不饱和脂肪酸（MUFA）含量（P = 0.08）。此外，常规血液检测、血液生化指标和组织病理学检查均未发现异常。总体而言，增加NCG水平并未线性改善上述指标；0.1%剂量效果最佳，高剂量（1%）未构成毒性风险。
