Effects Of Adding Mycotoxin Degraders To Diet Natural Contaminated With Mycotoxins On Growth Performance,Immune Function,Antioxidant Capacity And Intestinal Health Of Weaned Piglets

Deoxynivalenol（DON）and aflatoxin（AF）are widely presented in naturally moldy grains and diets,which can directly damage the intestine,liver and other organs by ingestion with contaminated diets,resulted in serious health problems in animals.There are various methods for mycotoxins detoxification,and the biological method has become a focus for mycotoxins elimination,due to its strong specificity,high efficiency and environmental friendliness.The aim of this experiment was to investigate the effects of adding different doses of a new complex mycotoxin degrader product（MS,with vomitoxin-degrading enzyme,aflatoxin B1-degrading enzyme and zearalenone degrading enzyme as main ingredients）to diets naturally contaminated with mycotoxins on growth performance,liver and intestinal health in piglets,and to compare the effect with a commercial mycotoxin degrader product（MR,with complex minerals and inactive yeast as main ingredients）.A total of 120 DLY piglets with an initial body weight of（6.89±0.14 kg）were randomly divided into 5 treatments:control group（CON）,moldy diet group（MD,naturally contaminated with DON 1870μg/kg,AFB₁10.02μg/kg）,moldy diet+1 g/kg MS group（1‰MS）,moldy diet+2 g/kg MS group（2‰MS）,moldy diet+1.5 g/kg MR group（1.5‰MR）,8 replicates per treatment and3 pigs per replicate.The experiment lasted for 35 d.（1）Compared to the control group,moldy diet significantly reduced ADFI of piglets during 1-21d,22-35d and 1-35d of the trial（P<0.05）,and tended to decrease ADG during 22-35d（P=0.06）and 1-35d（P=0.09）.MS and MR supplementation to the moldy diet could alleviate the decrease in feed intake and daily weight gain of piglets caused by mycotoxins.Compared with MD group,ADFI and ADG of piglets in2‰MS group increased by 16.39%（P<0.05）and 16.00%（P>0.05）,respectively.（2）Compared to the control group,the jejunal villus height and the ratio of villus height-to-crypt depth were significantly lower in MD group（P<0.05）.The addition of mycotoxin degraders all alleviated the mycotoxin-induced morphological damage,in particular,the jejunal villus height in 2‰MS group increased by 12.25%（P<0.05）.（3）Down-regulation of SLC7A1（P<0.05）and SGLT-1（P=0.07）m RNA expression in jejunal mucosa of piglets fed on moldy diet was observed.Addition of 2‰MS and 1.5‰MR both significantly inhibited the down-regulation of SLC7A1 m RNA expression（P<0.05）.（4）Piglets fed moldy diet had higher serumγ-GT and GOT activities on d 22 and d 36（P<0.05）.Supplemented with 1‰MS and 2‰MS significantly inhibited the increase in serum GOT activity on d 22 and d 36（P<0.05）,and the addition of 1.5‰MR significantly inhibited the increase in serumγ-GT and GOT activity on d 22（P<0.05）.（5）Moldy diet significantly increased serum IL-6 and TNF-αlevels on d 36（P<0.05）and dereased serum IL-10 levels（P=0.06）.Serum levels of IL-6 and TNF-αwere significantly down-regulated in MS and MR groups（P<0.05）,and the level of s Ig A in jejunum was increased by 25.73%（P<0.05）in the 2‰MS group,compared with MD group.（6）Moldy diet significantly reduced serum activities of GSH-Px and GSH-ST,liver GSH-Px activeies,and jejunal mucosa T-AOC,T-SOD and GSH-ST activeies（P<0.05）,and significantly increased the content of PCO in jejunal mucosa（P<0.05）.Compared with MD group,the piglets in 2‰MS group had higher T-AOC,GSH-Px and GSH-ST activities and lower MDA content in serum（P<0.05）,higher T-AOC and lower MDA and PCO contents in liver（P<0.05）,and higher T-AOC content in jejunal mucosal（P<0.05）.At the same time,1.5‰MR group showed a significant increase in serum T-AOC,GSH-Px and GSH-ST activities（P<0.05）and a significant decrease in liver MDA content（P<0.05）.（7）Serum DAO activity was significantly higher（P<0.05）and the expression of Clandin-1,MUC1 m RNA and Occludin protein in jejunal mucosa was significantly lower（P<0.05）in piglets fed moldy diet.Addition of MS and MR significantly inhibited the decrease in Claudin-1 gene expression（P<0.05）.Furthermore,ZO-1 and Occludin protein expression and MUC1 gene expression in jejunal mucosa were significantly higher in both 1‰MS and 2‰MS groups,compared to MD group（P<0.05）.（8）Moldy diet significantly increased Caspase-9 m RNA（P<0.05）and Cleaved-caspase-3 protein expression（P<0.05）in jejunal mucosa of piglet.Addition of MS and MR significantly inhibited the elevation of Caspase-9 m RNA and Cleaved-caspase-3 and Cleaved-caspase-9 protein expression in jejunal mucosa of piglets（P<0.05）.In conclusion,the results indicated that consumption of moldy diet naturally contaminated with 1870μg/kg DON and 10.02μg/kg AFB₁ disrupted the redox balance of system,liver and jejunum,impaired the immune function of intestine,and damaged intestinal barrier,reduced the feed intake and inhibited the growth performance of piglets.Moldy diet supplemented with MS and MR degraders could alleviate the negative effects of DON and AFB₁ on antioxidant capacity,immunity and growth performance of piglets to a certain extent.Addition of 2‰MS had the most significant protective effect,the growth performance of piglets in 2‰MS group during the first three weeks and the whole period of the trial was better than that of the 1‰MS and 1.5‰MR groups,which was comparable to that of the control diet group.