The Comparison Of Detection Methods For Mycotoxins In The Matrix Of Feed Ingredient And Their Adsorption Ratios By Different Added Adsorbents

The content of zearalenone(ZEN),deoxynivalenol(DON)and aflatoxin B1(AFB1)in 47 feed ingredients,which were collected from present feed market in China,were surveillanced by ELISA metod at first and verified by HPLC method succedently for samples of severe mycotoxin contamination.The adsorptive efficiency of lab-prepared adsorbents to the natural contaminated mycotoxins in the matrix of feed ingredients were evaluated under simulated gastric-intestinal media,in vitro.Furthermore,the effect of natural contaminated DON and the eliminating effect of adsorbent addition on the performance and the detrimental morphyological alterations in the digestive tract of piglets were evaluated using DON containing gradient diets.Experiment 1.The occurrence of mycotoxins in the investigated feed ingredientsMore than 44 feed ingredients,including distiller's residues,corn byproducts,oil-seed meals and cakes,grain brans,corn kernels,single-cell proteins,wheat byproducts,and other cereal kernals,were surveillanced by ELISA method.Succedently using HPLC method,verified for samples of severe mycotoxin contamination.The results show:Among the 47 analyzed feed ingredients,the ZEN was detected in all the grain brans,distiller's residues,oil-seed cakes and meals(the detection ratio was 100.0%)except in corn kernels(87.5%).The average ZEN content in distiller's residues,corn byproducts,oil-seed meals and cakes,grain brans,corn kernels,single-cell proteins,wheat byproducts,and other cereal kernals were 3344.78,1075.27,305.00,197.09,80.64,47.18,23.60,and 177.36 ?g/kg,respectively.The ZEN content in 66.7%of distiller's residue samples excessed the feed standard limitation of our country,however,that in other cereal kernals,corn kernels,single-cell proteins and wheat byproducts were within the limitation.The DON was detected in all the 44 samples analyzed.Among them,grain bran was of highest average DON content(4781.38 ?g/kg),and the DON content in 100.0%of corn byproduct,75.0%of distiller's residue and wheat flour,50.0%of grain bran,and 16.7%of oil-seed meal and cake was excessed the standard limit of our country.The highest average content of AFB1 was found in oil-seed cakes in this investigation with 16.7%and 30.8%of distiller's residues and oil-seed meals and cakes over the hygenic limitation of our country and no over-dose for other feed ingredients.Expt.2.Evaluation of Adsorption Eficiency of Adsorbents to Mycotoxins in Simulated gastriointenstinal EnvironmentThe adsorptive efficiency of lab-prepared adsorbents to the natural contaminated mycotoxins in the matrix of feed ingredients were evaluated under simulated gastric-intestinal media,in vitro.And evaluate the adsorptive efficiency on pure ZEN simulated intestinal media,in vitro.Furthermore compared the difference between the two evaluation methods.The results show:The adsorption efficient of lab-prepared adsorbent 2-B-2 to the ZEN originated from either barley or DDGS matrix was significantly superior than that of bentonite and a commercial absorbent(designated by P in the following context).The adsorption ratio of adsorbent 2-B-2 to ZEN from corn gluten meal matrix was 55.27 ± 2.94%,and to ZEN from DDGS matrix was 59.04 ± 7.60%,however,that to ZEN from corn protein feed matrix was much lower,16.92 ± 8.49%.The highest adsorption was monitored when the lab-prepared adsorbent 2-B-1 was used to absorb the ZEN in DDGS matrix(62.35 ± 2.11%),and the lowest was found when the adsorbent 1-B-0.5 was used to adsorb the ZEB in DDGS matrix.The adsorbents 2-B-2,P and bentonite exhibited higer adsorptive efficients to the DON in DDGS matrix than that of in barley.The adsorption efficiency of 2-B-2 to the ZEN and DON was significantly higher than other absorbent.The adsorption efficiency of 2-C-1 to the DON in DDGS matrix was significantly inferior other 6 absorbent.All the 7 adsorbents had lower adsorptive efficiency to the pure ZEN in simulated intestinal media,the adsorption efficiency of 2-B-2 and 2-A-0.5 reduced by 83.96%and 73.14%(P<0.05),respectively.Expt.3.Growth performance and Intestinal morphology in Adsorbent or deoxynivalenol(DON)-challenged Weaned pigletsAccording to the efficient adsorption of lab-prepared adsorbents to the natural DON in the matrix of feed ingredients under simulated gastric-intestinal media,in vitro.One of objective of this study was the effect of natural contaminated DON on the performance and the detrimental morphological alterations in the digestive tract of piglets were evaluated using DON containing gradient diets,the other was the mitigative effect of adsorbent addition on natural contaminated DON.In the first part of this study a total of ninety-six 5 week-old healthy weaning pigs were randomly divided into 4 groups(3 replicates per treatment,8 pigs per replicate).The DDGS naturally contaminated with severe DON was used as a source of experimental diet.In order to study the effect of natural DON on the performance and the digestive tract of piglets.The pigs in the 4 groups were fed experimental diets containing different levels of DON,which were<500 ?g/kg(group control)?1000 ?g/kg?2000 ?g/kg and 3000 ?g/kg,respectively.In the second part of this study a total of One hundred and forty-four 5 week-old healthy weaning pigs were randomly divided into 6 groups(3 replicates per treatment,8 pigs per replicate).This diet applied the same source as above.Pigs were fed diets containing two levels of DON<500 and 3000 ?g/kg,each diet was added with A or B two adsorbents of 0 or 1 kg/T,with a total of six kinds of different diets.The eliminating effect of adsorbent addition on the performance and the detrimental morphological alterations in the digestive tract of piglets were evaluated in this part of study.when compared with control group,pigs in 1000 ?g/kg?2000 ?g/kg and 3000?g/kg group tended to have reduced average feed intake(AFI),reduced by 4.86%?13.13%and 27.96%.No significant differences were observed between containing different levels of DON group and the control groups with regard to the AFI(P>0.05).The AFI in 3000 ?g/kg group reduced by 31.93%,and was significantly inferior to control group(P<0.05).The AFI of pigs in control+A group and control+B group reduced to 24.15%(P>0.05)and 30.75%(P<0.05)compared with their control group,respectively.No significant differences were observed in all experiment groups regard to the weight(P>0.05).Using the jejunal tissue section to observe the intestinal morphology of pigs.The results showed as follows:feeding diet contaminated with natural DON also causes morphological changes in the intestinal mucosa,such as villi flattening and shortening,apical necrosis hyperemia and intestinal rupture.It is concluded that the growth performance of piglets fed DON-contaminated diets is reduced,while adsorbent may improve the growth performance of weaner piglets and can alleviate intestine damage induced by DON.