不同氨化处理黄曲霉毒素B1脱毒效果及其对奶牛瘤胃体外发酵的影响

摘要

This experiment was conducted to study the detoxification effect of amination on aflatoxin B1 (AFB1) by different ammonia treatments and its effect on the in vitro fermentation of dairy cows.This experiment was divided into two sections.Trial 1:The corn and rice mixture (1∶3) artificially infected with 2 550μg/kg AFB1 were ammoniated, and they were randomly divided into control group (groupⅠ, untreated) and test groupsⅡ (0.1Mpa, 1h) , Ⅲ (0.1Mpa, 2h) , Ⅳ (0.1Mpa, 3h) , Ⅴ (0.2Mpa, 1h) , Ⅵ (0.2Mpa, 2h) , Ⅶ (0.2Mpa, 3h) , Ⅷ (0.3Mpa, 1h) , Ⅸ (0.3Mpa, 2h) , Ⅹ (0.3Mpa, 3h) with 3duplicates per group according to the difference in ammonia pressure and period.The detoxification effect of different ammonia treatments on AFB1 and nutrient composition of the mixture were determined.Trial 2:The trail was divided intofour treatments:Control group (group Ⅰ, untreated) and test groups Ⅱ (0.3 Mpa, 1h) , Ⅲ (0.3Mpa, 2h) andⅣ (0.3Mpa, 3h) with 3duplicates per group to explore the effect of ammoniated AFB1 on the in vitro fermentation of dairy cows.The gas production, pH, in vivo dry matter degradation rate (IVDMD) , ammonia nitrogen (NH3-N) and volatile fatty acid (VFA) of the fermentation broth were measured after 2, 4, 8, 12, 24 and 48hfermentation.The results showed that, in trail 1, the CP content of the test groups were significantly higher than that of control group (P<0.05) ;The AFB1 content of the group Ⅹ (0.3 Mpa, 3h) was significantly lower than that in the other groups (except groupⅦ) (P<0.05) .In trail 2, the pH of fermentation broth of group Ⅳ (0.3Mpa, 3h) was significantly lower than that of control group (P<0.05) , and the gas production, VFA, NH3-N content and IVDMD (except 48h) were significantly higher than that of control group (P<0.05) , while the effects of groupsⅡandⅢ were not obvious.In summary, ammonia treatment could significantly reduce the content of AFB1, increase the CP content, and then improve the efficiency of ruminal fermentation, in which the treatment of0.3Mpa, 3hhad the best effect.%试验旨在研究不同氨化处理对黄曲霉毒素B1 (AFB1) 的脱毒效果及其对奶牛瘤胃体外发酵的影响.本研究分为两个试验.试验一:对人工感染2 550μg/kg AFB1的玉米和大米混合物 (1∶3) 进行氨化处理, 分为对照组 (Ⅰ组, 未处理) 和试验组Ⅱ (0.1Mpa, 1h) 、Ⅲ (0.1 Mpa, 2h) 、Ⅳ (0.1 Mpa, 3h) 、Ⅴ (0.2 Mpa, 1h) 、Ⅵ (0.2 Mpa, 2h) 、Ⅶ (0.2Mpa, 3h) 、Ⅷ (0.3Mpa, 1h) 、Ⅸ (0.3Mpa, 2h) 、Ⅹ (0.3Mpa, 3h) 组, 每组3个重复, 测定不同氨化处理的AFB1的脱毒效果及混合物的营养成分.试验二:研究氨化处理AFB1对奶牛体外发酵指标的影响.试验设对照组 (Ⅰ组, 未处理) 和试验组Ⅱ (0.3Mpa, 1h) 、Ⅲ (0.3Mpa, 2h) 、Ⅳ (0.3Mpa, 3h) 组, 每组3个重复, 测定体外发酵2、4、8、12、24和48h的产气量、发酵液pH、体外干物质降解率 (IVDMD) 、氨态氮 (NH3-N) 和挥发性脂肪酸 (VFA) .结果显示:在试验一中, 试验组粗蛋白质 (CP) 含量均显著高于对照组 (P＜0.05);Ⅹ组 (0.3 Mpa, 3h) AFB1含量显著低于其他组 (除Ⅶ组外) (P＜0.05) .在试验二中, Ⅳ组 (0.3 Mpa, 3h) 发酵液pH显著低于对照组 (P＜0.05), 体外发酵产气量、挥发性脂肪酸、氨态氮含量和体外干物质降解率 (除48h外) 均显著高于对照组 (P＜0.05), 而Ⅱ (0.3Mpa, 1h) 和Ⅲ组 (0.3Mpa, 2h) 组效果不明显.综上所述, 氨化处理能够显著降低样品中AFB1含量, 提高CP含量, 改善瘤胃发酵, 其中0.3Mpa、3h处理效果最佳.