PSVIII-8 Effects of heat stress and arginine on intestinal morphology and hepatic metabolism in finishing pigs

Abstract

Abstract Heat stress can affect growth performance and some physiological metabolism in finishing pigs. In this study, we investigated the effects of intermittent heat stress and arginine on the growth performance, intestinal health and liver metabolism of finishing pigs. Forty-eight Landrace barrow pigs (about 70kg) were randomly assigned to 6 groups, each group 8 pigs. The pigs were treated as follows: (1) LR (fed ad libitum at 22°C), (2) HR (ad libitum fed at 35°C), (3) LL(at 22°C, but fed the amount consumed by those kept at 35°C), (4) LR+1% Arg, (5) HR+1%Arg, (6) LL+1%Arg. The temperature of HR and HR+1%Arg groups was controlled for cycles of 35 ± 2 ℃ for 12 hours, 22 ± 2 ℃ for the other 12 hours. The experiment lasted for 30 days. The results showed that the ADFI and ADG of pigs in LR group were much higher than those in HR group or LL group, the latter having the highest F:G (P < 0.05). Jejunal HE staining results showed that heat stress decreased the villus height of jejunum and villus height to crypt depth ratio, adding 1% arginine can alleviate the damage by heat stress (P < 0.05). Heat stress decreased the abundance of transcripts of tight junction protein ZO-1, occludin and mucin-2 in the mucosa of the jejunum (P < 0.05). Moreover, dietary arginine supplementation increased occludin transcripts (P < 0.05). The results of hepatic metabolomics showed that heat stress significantly affected the metabolism of carbohydrate, energy and protein of liver (P < 0.05). In conclusion, these data indicated that intermittent heat stress has negatively influence on the intestinal health and liver metabolism of finishing pigs, and adding 1% arginine had a positive effect on intestinal mucosal morphology caused by heat stress.