The study of the effect of natural contamination of feed with mycotoxins on the occurrence of diseases in farm animals.

(1)2000-2004年，对泰国饲料及其原料中黄曲霉毒素B1（AFB 1）、玉米赤霉烯酮（ZEA）和脱氧雪腐镰刀菌烯醇的污染情况进行了调查。其中，木薯受霉菌毒素污染最严重。(2)污染霉菌的分析显示，黄曲霉，黑曲霉，。成品饲料中的青霉、玉米中的黄曲霉和黑曲霉、木薯中的青霉和拟青霉、米糠中的根霉为优势霉菌。(3)收集木薯样品并分析霉菌毒素和霉菌污染。部分样品检出黄曲霉和镰刀菌等曲霉属，但大部分样品检出真菌毒素，AFB 1、AFB 2、AFG 1、AFG 2和ZEA的最高浓度分别为31.3ppb、18.2ppb、53.4ppb、48.5ppb和189.4ppb。(4)对猪体内黄曲霉毒素代谢的研究表明，猪的高敏感性反映了其肝脏谷胱甘肽S-转移酶活性较低，而还原酶活性与黄曲霉毒素毒性的种属差异无关。(5)给猪喂饲含香豆素或茶叶提取物的饲料一个月，然后研究了单次口服黄曲霉毒素B_1对猪的毒性作用。在香豆素中观察到处理对AFB 1毒性和组织残留的抑制作用，但在茶提取物中没有。

(1) In 2000-2004, aflatoxin B1 (AFB1), zearalenon (ZEA) and deoxynivalenol contamination in feed and its materials were surveyed in Thailand. Among them, cassava was most heavily contaminated with mycotoxins. (2) Analysis of contaminated molds revealed Aspergillus flavus、 A.nigar、. and Penicillium in completed feeds, Aspergillus flavus and A.nigar in corn, Penicillium and Paecilomyces in cassava and Rhizopu in rice bran, as dominant molds. (3) Cassava samples were collected and analyzed for mycotoxin and mold contamination. Aspergillus sp including A.flavus and Fusarium sp were found in a part of the samples, but mycotoxins were detected in most of them, the maximum concentrations of AFB1,AFB2,AFG1,AFG2 and ZEA being 31.3ppb、 18.2ppb、 53.4ppb、 48.5ppb and 189.4ppb, respectively. (4) The study of aflatoxin metabolism in pigs demonstrated that high susceptibility of pigs reflects lower hepatic glutathion S-transferase activity compared with the other animal species, and that the reductase activity is not involved in the species difference of aflatoxin toxicity. (5) Pigs were given the feed containing coumarin- or tea extract for one month, and then toxic effects of a single oral administration of AFB1 in them were studied. Inhibitory effects of the treatment on toxicity and tissue residue of AFB1 were noted slightly in coumarin, but not in tea extract.