中文摘要：高产牛奶和牛肉要求牛饮食中富含淀粉，而这种做法可能诱发牛瘤胃酸中毒，以及增加真菌毒素暴露，这是因为饮食中的淀粉是霉菌毒素污染的主要载体。本研究旨在调查低瘤胃pH值对四种主要霉菌毒素（黄曲霉毒素B1（AFB1），赭曲霉毒素A（OTA），脱氧雪腐镰刀菌烯醇（DON）和伏马菌素B1（FB1））的生物利用率的影响情况。研究结果表明，高淀粉饮食增加了OTA和AFB1的生物利用度，会潜在增加对这些真菌毒素的毒性作用。
外文摘要：High-production dairy and beef systems require diets rich in starch. This practice may induce ruminal acidosis and also increase exposure to mycotoxins because starches in starch-rich diets are the main vehicles of mycotoxin contamination. The aim of this study was to investigate the effects of low ruminal pH on the bioavailability of 4 major mycotoxins [i.e., aflatoxin B1 (AFB1), ochratoxin A (OTA), deoxynivalenol (DON), and fumonisin B1 (FB1)]. Eight nonlactating dairy cows fitted with rumen cannulas were used in a double crossover experiment. The trial was divided into 4 periods with 2 periods per crossover. Cows were divided into 2 groups receiving a low (15% dry matter basis) and high-starch diet (30.8%) with and without live yeast supplementation (1×1010 cfu per cow) in the first and second crossover, respectively. At the end of each period, cows received a single dose of mycotoxin-contaminated feed containing 0.05, 0.2, 0.24, and 0.56mg of AFB1, OTA, DON, and FB1 per kg of feed, respectively. The fecal and urinary excretion of mycotoxins and their metabolites was monitored for up to 48h postdosing. As expected, ruminal pH decreased in cows fed the high-starch diet. The high-starch diet increased the bioavailability of OTA and AFB1. Urinary excretion of OTA 24h after mycotoxin administration increased 3-fold in the high-starch diet, correlated with lower fecal excretion. Similarly, a decrease in fecal excretion of AFB1 was accompanied by an increase in urinary excretion of its major metabolite, aflatoxin M1, 48h after mycotoxin administration. In contrast to AFB1 and OTA, the bioavailability of DON and FB1 remained unchanged. Yeast supplementation had no effect on the excretion balance of these 2 mycotoxins. In conclusion, these results show that high-starch diets increased the bioavailability of OTA and AFB1, most probably through the lowering effect on ruminal pH. This greater bioavailability potentially increases the toxic effects of these mycotoxins.
外文关键词：mycotoxin；low ruminal pH；dairy cow；live yeast supplementation
作者：Pantaya, D.; Morgavi, D. P.; Silberberg, M.; Chaucheyras-Durand, F.; Martin, C.; Suryahadi; Wiryawan, K. G.; Boudra, H.
作者单位：INRA,France.
期刊名称：JOURNAL OF DAIRY SCIENCE
期刊影响因子：2.408
出版年份：2016
出版刊次：12
点击下载：淀粉诱导的非哺乳期奶牛低瘤胃pH值条件下，黄曲霉毒素B2和赭曲霉毒素A的生物利用率增加，而伏马菌素B1或脱氧雪腐镰刀菌烯醇的生物利用率未增加。