N-carbamylglutamate (NCG) and arginine were investigated with their effects on growth performance and maintain intestinal health in early-weaned piglets. Eighty-nine Landrace×Yorkshire piglets from 12 pens (average pen weight 5.56±0.51 kg; weaned at 21 d) were grouped into 3 treatment groups and fed one of the following diets for 7 days: a standard diet (SD), SD+NCG (0.08％), or SD+Arg (0.6％). Six piglets were randomly selected from each group and slaughtered. Compared with the control group, NCG and Arg each significantly increased ADG and ADFI (P<0.05). The incidence of diarrhea in the NCG group was lower (P<0.01) than those in the control and Arg groups (18.13 and 12.52％, respectively). Both NCG and Arg significantly increased the average intestine weight (P<0.05). Based on a comparison with the control group, the addition of Arg to the diet resulted in a greater villus height (P<0.05) in the duodenum and jejunum. Piglets fed NCG showed a similar trend in villus height. Goblet cell counts significantly increased in the ileum (P<0.05) in response to supplementation with Arg. NCG and Arg significantly increased serum Arg (P=0.028) and Ornithine (P=0.022) comparing to the control group. Serum citrulline increased 33.60 and 39.72％ in the NCG and Arg groups (P=0.221), respectively. Accordingly, serum NO tended to increase (P>0.05), and iNOS significantly increased (P<0.05) in the NCG group. NO in intestinal mucosa significantly increased in the Arg group (P=0.044), as well as in the NCG group (P>0.05). Real-time PCR showed that the expression of HSP70 mRNA was higher in ileum mucosa in the Arg and NCG groups (P<0.05). These results indicated that dietary supplementation with 0.08％ NCG or 0.6％ Arg could improve growth performance, stimulate intestinal growth and prevent intestinal mucosa dysfunction in weaned piglets. These findings indicate that NCG is a functional ingredient for weaning piglet in terms of supporting endogenous Arg synthesis, and may be able to more effectively alleviate weaning stress through an Arg-NO-HSP70 pathway than L-Arg.
Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of SubtropicalAgricult China National Key Laboratory of Animal Nutrition, Beijing Animal and Veterinary ScienceInstitute, C Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University,Wuhan, China Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan, Chin