【作者】 徐雪梅；

【导师】 齐德生；

【作者基本信息】 华中农业大学 ， 动物营养与饲料科学， 2008， 硕士

【摘要】 本研究通过体外等温吸附试验和解吸试验,研究了葡甘聚糖、葡甘聚糖与膨润土复合物及乙酸酐改性葡甘聚糖对黄曲霉毒素B₁（AFB₁）、玉米赤霉烯酮（ZEA）、脱氧雪腐镰刀菌烯醇（呕吐毒素,DON）的吸附效果,筛选出吸附效果好的吸附剂,通过动物饲养试验及生理生化分析,研究其对霉菌毒素混合污染的脱毒效果。1.体外试验研究了葡甘聚糖、葡甘聚糖与膨润土复合物（比例9:1）Ⅰ、葡甘聚糖与膨润土复合物（比例4:1）Ⅱ、葡甘聚糖与膨润土复合物（比例2:1）Ⅲ、葡甘聚糖与膨润土复合物（比例1:1）Ⅳ、膨润土、乙酸酐改性葡甘聚糖等7种吸附剂对AFB₁、ZEA、DON的吸附规律和解吸情况。结果表明:葡甘聚糖、葡甘聚糖与膨润土复合物及乙酸酐改性葡甘聚糖对AFB₁、ZEA的等温吸附,均符合Langmuir方程,吸附方式为单分子层吸附;而膨润土对ZEA的等温吸附,既不复合Freundlich方程又不符合Langmuir方程。pH2.0条件下,以葡甘聚糖与膨润土复合物（比例1:1）Ⅳ对AFB₁、ZEA的最大吸附量最高,分别为250μg/g、1776μg/g。pH8.0时,以葡甘聚糖与膨润土复合物（比例1:1）和葡甘聚糖与膨润土复合物（比例2:1）Ⅲ对AFB₁的最大吸附量最高,为217.39μg/g;葡甘聚糖与膨润土复合物（比例1:1）Ⅳ对ZEA的最大吸附量最高,为1324μg/g。两种pH条件下,葡甘聚糖与膨润土复合物（比例1:1）Ⅳ对AFB₁、ZEA的解吸率也较低。另外,所有吸附剂对DON的等温吸附既不符合Freundlich方程又不符合Langmuir方程,且吸附效率偏低。综合体外试验结果,选用葡甘聚糖与膨润土复合物（比例1:1）Ⅳ（以下简称复合脱毒剂）进行动物试验。2.动物试验选用健康、体重一致的1周龄Avian肉用仔鸡240只,随机分为8个处理组,每组5个重复,每个重复6只鸡,分栏饲养,试验鸡自由采食和饮水。各组分别饲喂基础日粮、霉变日粮、基础日粮添加0.05%复合脱毒剂、霉变日粮分别添加0.05%复合脱毒剂、0.1%复合脱毒剂、0.1%市售脱毒剂、0.3%酵母细胞壁葡甘聚糖Ⅰ、0.3%酵母细胞壁葡甘聚糖Ⅱ,即为对照组、污染组、处理1、处理2、处理3、处理4、处理5和处理6。试验分2个阶段（2～4周龄,2～7周龄）,共42d。于试验第1d、21d和42d,每组逐只称重,以重复为单位计算耗料量,并在第21d和第42d从每重复随机选取2只鸡,颈静脉放血后处死。研究霉变饲料中添加各种脱毒剂对肉鸡生长性能、肝脏损伤、霉菌毒素残留以及免疫系统的影响,以探讨几种脱毒剂对霉变饲料的实际脱毒效果。试验结果如下:对生长性能的影响:所有脱毒剂在不同阶段对肉鸡的生长性能有不同的影响,对前期的影响较为明显。从全期饲养结果显示,霉变饲料中添加0.1%复合脱毒剂、0.1%市售吸附剂、0.3%酵母细胞壁葡甘聚糖Ⅰ后,各处理组肉鸡的平均日增重均高于污染组（p＜0.05）,其中以0.1%复合脱毒剂的添加组最好,比污染组提高了10.22%,恢复到了对照组的水平;与污染组相比,霉变饲料中添加所有脱毒剂后均降低了料重比,其中,处理3和4与污染组差异显著（p＜0.05）,与对照组无显著性差异（p＞0.05）。对肝脏功能的影响:各处理组对血清中AST、ALT、AKP和γ-GT均有不同程度的影响。第一阶段,污染组血清中AKP显著高于对照组（p＜0.05）,血清中AST以0.1%复合脱毒剂的添加组最低;第二阶段,霉变饲料组动物血清中AST、ALT和γ-GT均显著高于基础日粮组（p＜0.05）,0.1%复合脱毒剂添加组血清中AST、ALT和γ-GT均比霉变饲料组低（p＜0.05）;总体来看,与对照相比,霉变饲料组显著降低了血清中总蛋白和白蛋白的浓度（p＜0.05）。与污染组相比,0.1%复合脱毒剂添加后显著提高了第一阶段血清中白蛋白的浓度（p＜0.05）,其他添加组与污染组相比,血清中白蛋白和总蛋白有提高的趋势,但差异不显著（p＞0.05）。对免疫功能的影响:第一阶段,霉变饲料组脾脏指数显著高于正常饲料组,法氏囊指数显著低于对照组,0.1%复合脱毒剂添加组脾脏指数显著低于污染组（p＜0.05）,但未达到对照组水平;第二阶段,霉变饲料组法氏囊指数显著低于基础日粮组（p＜0.05）,0.1%复合脱毒剂添加组法氏囊指数显著高于霉变饲料组（p＜0.05）,但未达到对照组水平。总体来看,污染组肉鸡新城疫抗体滴定显著低于对照组（p＜0.05）,各脱毒剂的添加,均使肉鸡新城疫抗体滴定有增加的趋势,其中以处理3为最高,但未达到显著水平（p＞0.05）。对器官相对重量的影响:第一阶段,霉变饲料组肝脏、肾脏、肌胃相对重量显著高于基础日粮组（p＜0.05）,0.1%复合脱毒剂添加组肾脏相对重量显著低于霉变饲料组（p＜0.05）,且与对照无显著差异（p＞0.05）;第二阶段,霉变饲料组肝脏、肾脏、卵巢、睾丸相对重量显著低于基础日粮组（p＜0.05）,而在霉变饲料中加入0.1%复合脱毒剂后,肝脏、肾脏、卵巢、睾丸相对重量均有升高趋势,但与污染组相比,差异不显著（p＞0.05）。对肝脏、肌肉组织中霉菌毒素残留量的影响:各处理组,肉鸡肝脏、肌肉组织中霉菌毒素残留量均未检出。以上结果表明:与污染组相比,霉变饲料中添加0.1%复合脱毒剂、0.1%市售吸附剂和0.3%酵母细胞壁葡甘聚糖Ⅰ,对肉鸡的生长性能有明显的改善作用,其中以0.1%复合脱毒剂的添加最为显著。0.1%复合脱毒剂对肉鸡饲喂霉变饲料后肝脏功能具有显著的保护作用。更多还原

【Abstract】 The experiments were conducted to study the effect of glucomanan, glucomanan-bentonite compounds and anhydride modified glucomanan on the adsorption of aflatoxin B₁（AFB₁）,zearalenone（ZEA） and deoxynivalenol（DON） by isothermal adsorption experiment in vitro and desorption experiment,and then to obtain the adsorbent of the best adsorption effect,and evaluate the detoxification effect on mycotoxins by broiler raise test and physiological biochemistry analysis.1.The vitro experimentThe vitro experiment was shown to study the effect of glucomanan,9:1 glucomanan-bentonite compoundⅠ,4:1 glucomanan-bentonite compoundⅡ,2:1 glucomanan-bentonite compoundⅢ,1:1 glucomanan-bentonite compoundⅣ,bentonite and acetic anhydride modified glucomanan on the adsorption of aflatoxin B₁（AFB₁）, zearalenone（ZEA） and deoxynivalenol（DON）,and the efficiency of 7 adsorbents to detoxify aflatoxin B₁（AFB₁）,zearalenone（ZEA） and deoxynivalenol（DON）.The results of the vitro experiment were as following:The isothermal adsorption of AFB₁ and ZEA on glucomanan,glucomanan-bentonite compounds and anhydride modified glucomanan were all fitted Langmuir equation from the fitting degree.The adsorption styles were monolayer adsorption;While the isothermal adsorption of ZEA on bentonite was not fitted neither Langmuir equation nor Freundlich equation from the fitting degree The maxium amount of AFB₁ and ZEA adsorbed on 1:1 glucomanan-bentonite compound was 250μg/g,1 776μg/g respectively at pH2.0,and it was the biggest.The maxium amount of AFB₁ adsorbed on 1:1 glucomanan-bentonite compoundⅣand 2:1 glucomanan-bentonite compoundⅢwas the biggest,217.39μg/g at pH8.0;The maxium amount of ZEA adsorbed on 1:1 glucomanan-bentonite compoundⅣwas also the biggest,1 324μg/g at pH8.0.The efficiency of 1:1 glucomanan-bentonite compoundⅣto detoxify AFB₁ and ZEA is very low.Furthermore,the isothermal adsorption of DON on all adsorbents were not fitted neither Langmuir equation nor Freundlich equation from the fitting degree,in addition,the adsorption effeciency on DON were very low.Therefore,1:1 glucomanan-bentonite compoundⅣ（to be called for short as detoxification compound） was carried out to be authenticated in broiler experiment.2.Chronic toxicity experiment with broiler240 1-week-old Avian broiler chickens were randomly allotted into 8 treament groups[5 replicates of 6 each]from days 1 to 42 for a two-phase trial（2-4 weeks,2-7 weeks）.The 8 dietary treatments consisted of:（1） control,basal diet;（2） contaminated group,mycotoxins contaminated diet;（3） group 1,0.05%detoxification compound added to basal diet;（4） group 2,0.05 detoxification compound plus mycotoxins contaminated diet;（5） group 3,0.1%detoxification compound plus mycotoxins contaminated diet;（6） group 4, 0.1%marketing adsorbent plus mycotoxins contaminated diet;（7） group 5,0.3% glucomananⅠof yeast cell wall plus mycotoxins contaminated diet;（8） group 6,0.3% glucomananⅡof yeast cell wall plus mycotoxins contaminated diet.Chickens were monitored daily and then body weight and feed consumption were recorded at 1,21,42 days of experiment.On the first day of trial and last day of every phase,2 broiler chickens from each replicate were taken out randomly,jugular bloodletting then slaughtered,blood samples were collected to determine physiological biochemical parameters and immune indexes.The experiment was conducted to evaluate the detoxification effect in broiler by studying effects on growth performance,the severity of lesions in the livers,immune function and mycotoxins residues in body tissues.The results showed as follows:The growth performance:There was different effects of all adsorbents on growth performance for broilers in the two phase.From the whole rearing period,with the addition of 0.1%detoxification compound,0.1%marketing adsorbent and 0.3%untreated glucomanan 1 of yeast cell wall to mycotoxins contaminated diet,average daily gain （ADG） increased all significantly（p＜0.05） compared to which in the mycotoxins contaminated diet,among the results,when 0.1%detoxification compound was added to mycotoxins contaminated diet,ADG increased by 10.22%compared to which in mycotoxins contaminated diet,However,ADG of all dietary treated groups were all lower than that with basal diet（p＞0.05）.Moreover,the feed/gain ratio all decreased with he addition of all adsorbents to mycotoxins contaminated diets and only which in the group of the addition of 0.1%detoxification compound and 0.1%marketing adsorbent to mycotoxins contaminated diet showed significantly difference in compasion to which in mycotoxins contaminated diets（p＜0.05）.The feed/gain ratio in the group of the addition of 0.1%detoxification compound to mycotoxins contaminated diet was the lowest.Liver damage:There were different effect on AST,ALT,AKP andγ-GT in serum of broiler chickens among all dietary treated groups.In the first phase,serum AKP with mycotoxins contaminated diet was significant higher than which in basal diet（P＜0.05）. Serum AST in the group of the addition of 0.1%detoxification compound to mycotoxins contaminated diet was lowest;In the second phase,serum AST,ALT andγ-GT with mycotoxins contaminated diet was significant higher than which in basal diet（p＜0.05）. With the addition of 0.1%detoxification compound,serum AST,ALT andγ-GT were all lower than those in mycotoxins contaminated diet（p＜0.05）.Through out the whole experiment,Compared with basal diet,mycotoxins contaminated diet decreased serum total protein,albumin remarkably（p＜0.05）.Serum albumin was significantly increased when 0.1%detoxification compound was added to mycotoxins contaminated diet（p＜0.05）. Serum total protein,albumi in other groups showed a trend of increase compared to which in mycotoxins contaminated diet,however,there was no significant differences（p＞0.05）.The immune function:In the first phase,spleen index in mycotoxins contaminated diet was significantly higher than that in basal diet.However,Bursa of Fabricius index in mycotoxins contaminated diet was significantly lower than that in basal diet.spleen index with the addition of 0.1%detoxification compound to mycotoxins contaminated diet was significantly lower than that in mycotoxins contaminated diet（p＜0.05）,however,it was not up to that of basal diet.In the second phase,Bursa of Fabricius index in mycotoxins contaminated diet was significantly lower than that in basal diet（p＜0.05）.Bursa of Fabricius index with the addition of 0.1%detoxification compound to mycotoxins contaminated diet was significantly lower than that in mycotoxins contaminated diet （p＜0.05）,however,it was not up to that of basal diet.Through out the whole experiment, New castle disease antibody titer in mycotoxins contaminated diet was significantly lower than that in basal diet（p＜0.05）,New castle disease antibody titer showed a trend of increase with the addition of all adsorbents to mycotoxins contaminated diet,that in group 3 was the highest,however,it was not up to significant level（p＞0.05）.The relative organ weights:In the first phase,the relative liver weight,the relative kidney weight and the relative stomachus muscularis weight in mycotoxins contaminated diet were all significantly higher than those in basal diet（p＜0.05）.the relative kidney weight with the addition of 0.1%detoxification compound tomycotoxins contaminated diet was significantly lower than that in mycotoxins contaminated diet（p＜0.05）,there was no significant difference compared to basal diet（p＞0.05）;In the second phase,the relative liver weight,the relative kidney weight,the relative ovaries weight and the relative testicle weight in mycotoxins contaminated diet was significantly lower than that in basal diet（p＜0.05）.With the addition of 0.1%detoxification compound to mycotoxins contaminated diet,the relative liver weight,the relative kidney weight,the relative ovaries weight and the relative testicle weight were all showed a trend of increase, however,there was no significant differences（p＞0.05）.Mycotoxins residues in body tissues:Mycotoxins residues in body tissues were all not detected in all groups.In conclusion,compared to mycotoxins contaminated diet,with the addition of 0.1% detoxification compound,0.1%marketing adsorbent and 0.3%glucomananⅠof yeast cell wall to mycotoxins contaminated diet,growth performance in broiler improved apparently. The effect with the addition of 0.1%detoxification compound is most siginificantly.There was significant protection from liver function when 0.1%detoxification compound was added to mycotoxins contaminated diet.更多还原