| Due to the serious pollution of ZEA,how to prevent effectively and reduce the damage is a scientific problem which needs to be solved urgently in feed industry and even animal husbandry.As the most important organ to absorb,metabolize and degrade ZEA,the digestive system is more exposed to toxins than other parts of the body.Therefore,intestinal mucosa is the most vulnerable part to the toxicity of ZEA and its metabolites.So this study specifically explored the effect of ZEA on intestinal function,and validated the application effect of specific complex enzymes.The aim of this study was to investigate the effects of low dose of zearalenone(1 mg/kg)on intestinal barrier defense,oxidative stress and nutrient uptake in weaned gilts.According to their age(35 ± 1 days of age)and average body weight(14.13 ± 0.80)kg,thirty healthy weaned gilts(Duroc × Landrace × Yorkshire)were divided into 3 treatments.There was no significant difference in initial body weight among groups(P > 0.05).Piglets in control were fed with basal diet.The diet of group 1 was supplemented with 1 mg/kg ZEA in the basic diet,while that of group 2 was supplemented with 2 000 mg/kg of special complex enzymes in the diet of group 1.After 7 days of adaptation,piglets were fed with experimental diet for 35 days.The results showed as follows:(1)ADG in ZEA1.0 group and ZEA1.0+M group was significantly higher than that in control group(P < 0.05).(2)ZEA decreased the villus height and crypt depth of duodenum and ileum(P < 0.01),and increased that of jejunum(P < 0.01).ZEA promoted the villus height to crypt depth of jejunum and ileum at the same time(P <0.05).(3)Compared with the control group,the small intestine of ZEA1.0 group had some morphological changes : duodenal villi were damaged,epithelium was exfoliated,small intestinal glands were sparse and duodenal glands became loose.The top of the jejunal villi was occasionally damaged,and the small intestinal glands were sparse and shorter.The lymph nodes in ileum were lighter and more numerous.Compared with ZEA1.0 group,the duodenal villous epithelium in ZEA1.0+M group was more complete and the damage was repaired;thesmall intestinal glands in jejunum were more dense;and the lymph nodes in ileum were darker.(4)The relative mRNA expression of claudin1 decreased in duodenum(P < 0.01)and increased in jejunum and ileum(P < 0.01),which was consistent with the expression of protein.The relative mRNA expression of occludin decreased in duodenum and jejunum(P <0.01),but increased in ileum(P < 0.01).Furthermore,The protein expression of occludin increased significantly in the small intestine(P < 0.05).The immunoreactivity of Nrf2 increased in duodenum,jejunum,ileum and mesenteric lymph nodes,showed the same law with the expression of mRNA and protein expression.ZEA significantly decreased the expression of CAT1 in jejunum and ileum was(P < 0.01),while significantly increased the expression of SGLT1 in small intestine was(P < 0.05).The experiment shows:(1)Because of the addition of ZEA(1 mg/kg),the weight gain of weaned piglets increased and the feed-Weight ratio decreased.(2)The effect of ZEA(1 mg/kg)on intestinal barrier function of weaned gilts was different.The prominent manifestation was that it destroyed the duodenum and protected the ileum.(3)ZEA supplemented with 1 mg/kg of diet could stimulate the small intestine and mesenteric lymph nodes,and ultimately led to oxidative stress.(4)The addition of ZEA(1 mg/kg)in gilts' diet could promote the transport of sugar in the intestine and inhibit the transport of amino acids in the jejunum and ileum.(5)The effect of ZEA could be reduced by adding special complex enzymes. |
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