益生菌发酵饲料条件优化及营养价值评定

Optimization of Fermented Feed Conditions and Nutritional Value Evaluation of Probiotics

为探究不同发酵条件对益生菌发酵饲料品质的影响,本试验选用毕赤酵母菌JZ10发酵精补料,采用3因素(接种量、水料比、温度)3水平正交设计对发酵条件进行优化,随机分为9个组,测定每组饲料中的氨态氮(NH_(3)-N)、可溶性糖(SS)、淀粉(ST)、pH,使用极差分析法找到综合指标最优的组合,测定饲料常规营养成分、霉菌毒素含量,从而确定最佳发酵时间。结果表明:(1)pH最优组为F3(接种量5%、发酵温度30℃、水料比1∶1),ST最优组为F_(1)(接种量5%、发酵温度30℃、水料比0.4∶1),NH_(3)-N最优组为F5(接种量10%、发酵温度25℃、水料比1∶1),SS最优组为F4(接种量10%、发酵温度20℃、水料比0.6∶1)。(2)发酵第5天,粗蛋白(CP)、ST、SS含量显著升高(P<0.05),pH、黄曲霉毒素B_(1)(AFB_(1))、呕吐毒素(DON)含量显著降低(P<0.05)。发酵第7天,中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)、玉米赤霉烯酮(ZEN)含量显著降低(P<0.05),NH 3-N含量显著升高(P<0.05)。精补料的最佳发酵条件为接种量10%,温度25℃,水料比1∶1,发酵时间5~7 d,可提高饲料的营养成分,降低霉菌毒素的含量。

To explore the effects of different fermentation conditions on the quality of probiotics fermented feed,Pichia pastoris JZ10 fermentation concentrate was used as a supplement,and the fermentation conditions were optimized by a 3-level orthogonal design with 3 factors(inoculation amount,water-to-feed ratio,and temperature)in this experiment.9 groups were assigned and the ammonia nitrogen(NH 3-N),soluble sugar(SS),starch(ST),pH were determined,the range analysis method was adopted to find the best combination of comprehensive indicators and determine the conventional nutrient composition and mycotoxin content of the feed,so as to determine the best fermentation time.The results showed that:(1)The optimal pH group was F_(3)(inoculation amount 5%,fermentation temperature 30℃,water-to-material ratio 1∶1),the optimal ST group was F1(inoculation amount 5%,fermentation temperature 30℃,water-to-material ratio 0.4∶1),the optimal NH_(3)-N group was F5(inoculation amount 10%,fermentation temperature 25℃,water-to-material ratio 1∶1),and the optimal SS group was F4(inoculation amount 10%,fermentation temperature 20℃,water-to-material ratio 0.6∶1).(2)On the 5th day of fermentation,the content of crude protein(CP),ST,and SS increased significantly(P<0.05),and the content of pH,aflatoxin B_(1)(AFB_(1))and vomiting toxin(DON)decreased significantly(P<0.05).On the 7th day of fermentation:the content of neutral detergent fiber(NDF),acid detergent fiber(ADF),and zearalenone(ZEN)decreased significantly(P<0.05),and the content of NH_(3)-N increased significantly(P<0.05).It is concluded that the optimal fermentation conditions for refined feed are:inoculum amount 10%,temperature 25℃,water-to-feed ratio 1∶1,fermentation time 5~7 days.It can improve the nutritional content of feed and reduce the content of mycotoxins.