The Study On Detoxification Effect Of Mycotoxin Adsorbent BZ For Zearalenone

In recent years,the pollution range of mycotoxin contaminations in feed remains wide,which reminds us the situation is still serious.Adsorbing mycotoxins with different kinds of adsorbents has been studied and applied mostly among all the methods,whose technics improves all the time.This study was based on zearalenone(ZEA)and a mycotoxin adsorbent modified from natural montmorillonite called BZ to evaluate the effect on adsorbing the mycotoxin and provide references for application in animal culture.Characterization measurement:observing superficial structure under scanning electron microscope;calculating specific surface area;comparing interlayer distance of natural montmorillonite and BZ before and after adsorption;comparing infrared spectrum of natural montmorillonite and BZ.Results showed that the particle of BZ was tinier and more homogeneous in size with smooth edge and fluffy structure.The specific surface area of BZ was smaller than that of natural montmorillonite.The interlayer distance increased after modification and adsorption of ZEA made it increased even more.The IR spectrum showed that-OH vibration at 3629 cm-1,3427 cm-1 and 1637 cm-1 weakened,while CH2 vibration at 2923 cm-1 and 2852 cm-1 and CH3 vibration at 1488 cm-1 were enhanced,which indicated that the quaternary ammonium salt modifier was intercalated into the interlayer of montmorillonite and removed some water of crystallization.In vitro experiment:evaluating the effect of different amount of adsorbent added,adsorbing time and solution pH on adsorption ratio of ZEA;evaluating the stability of adsorption via desorption experiment;analysing the adsorption model through isothermal adsorption test.Results showed that natural montmorillonite had poor effect on adsorbing ZEA and no obvious connections between adsorption ratio and conditions were observed.For BZ,there was positive correlation between adsorption ratio and the amount of adsorbent added.The adsorption ratio rose at the beginning and dropped afterwards with adsorption time extended.It reached the state of adsorption equilibrium around 90 min.When the solution pH rose from 3 to 7,the adsorption ratio increased gradually and the desorption ratio decreased,which indicated the adsorption of ZEA was more stable in neutral environment.The isothermal adsorption test revealed that the adsorption of ZEA by BZ fitted the Freundlich equation better,which meant it was monolayer adsorption.The max adsorption capacity was 5642.85 μg/g.In vivo experiment:evaluating adsorbing effect of BZ in the body via adding mouldy corn and BZ into feed.120 1-day-old Ross 308 broilers were selected and distributed randomly into six treatments(A:basal diet;B:basal diet with 0.2%natural montmorillonite;C:basal diet with 0.2%BZ;D:ZEA contaminated diet;E:ZEA contaminated diet and 0.2%natural montmorillonite;F:ZEA contaminated diet and 0.2%BZ)with 20 broilers per treatment.The experiment duration was 42 days(including 7 days of adaptation).The broilers were weighed weekly and average daily gain,average daily feed intake and feed conversion ratio were calculated.At the end of 6th week,the blood samples,liver,spleen,kidney,thymus,bursa of fabricius,reproduction organ and chest muscle were collected for the subsequent experiments.The adsorbing effect was evaluated by relative organ weights,serum biochemical parameters,anti-oxidative enzymes activities in serum,ZEA content in tissue and relative expressions of apoptosis-related mRNAs in reproductive system.Results indicated that BZ may not influence the broiler performance when added into normal feed and relieve growth performance retardation caused by ZEA in lightly contaminated feed to a certain degree.The addition of BZ may recover the relative organ weights effected by ZEA contamination.Serum biochemical parameters and anti-oxidative enzymes activities were not affected when BZ was added into normal feed,but the damage of liver,kidney and immune system and oxidative stress caused by the toxin could be relieved to some extent as BZ was added into the contaminated feed.No ZEA was detected in the examined tissues.The RT-qPCR results showed that relative expression of P53 and Caspase-3 gene in reproductive organ cells would increase when ZEA in broiler feed was just exceeding the national limit,while the addition of BZ could lighten the increasing expression of P53 and Caspase-3 so that reduce the cellular apoptosis.In summary,the adsorbent BZ,which was modified from natural montmorillonite,possessed a good adsorption effect of ZEA in vitro.It could reduce the damage of the toxin to a certain degree when added into lightly contaminated feed and had no adverse effects on normal broilers.