不同发酵时间对益生菌发酵饲料营养成分和品质的影响

Effects of different fermentation time on nutrient composition and quality of probiotics fermented feed

为了研究不同发酵时间对益生菌发酵饲料营养成分、体外消化率及饲料品质的影响,试验按照27.5%豆粕、50%酒糟粉、15%菜籽粕和7.5%血粉将饲料原料混合均匀,接种5%益生菌发酵液和35%水分,30℃密封发酵,测定在不同发酵时间时发酵饲料的营养成分、体外消化率、干物质回收率、乳酸菌数量、乳酸含量和pH值。结果表明:随着发酵时间的延长,饲料中粗蛋白(CP)含量持续显著升高(P<0.05),发酵第10天与发酵第15天比较差异不显著(P>0.05);发酵第15天真蛋白率显著低于发酵第30分钟(P<0.05);铵态氮(NH_3-N)含量和CP体外消化率均随着发酵时间延长极显著增加(P<0.01);与发酵第30分钟相比,各时间点干物质回收率均显著降低(P<0.05);饲料中乳酸菌数量随着发酵时间的延长先上升后下降,发酵第10天乳酸菌数量最高;乳酸含量随着发酵时间延长持续极显著升高(P<0.01);pH值随着发酵时间延长持续极显著降低(P<0.01)。说明在此次发酵条件下,最佳发酵时间为6 d,饲料营养成分含量、体外消化率、乳酸含量和乳酸菌数量均处于较好水平,干物质回收率较高。

To study the effects of different fermentation time on the nutrient composition,digestibility in vitro and feed quality of probiotics fer mented feed,the feed materials were mixed evenly according to the proportions of 27.5%soybean meal,50%vinasse powder,15%rapeseed meal,and 7.5%blood meal.It was then inoculated with 5%probiotic broth and 35%water and fermented at 30℃in a sealed container.The nutrient composition,digestibility in vitro,recovery rate of dry matter,lactic acid bacteria number,lactic acid content,and pH value were de termined at different fermentation time.The results showed that the crude protein content in the feed increased significantly with the prolongation of fermentation time(P<0.05).There was no significant difference between the 10th day and 15th day(P>0.05).True protein rate on the 15th day was significantly lower than that on the 30th min(P<0.05).The content of ammonium nitrogen and in vitro digestibility of crude protein were significantly increased with the prolongation of fermentation time(P<0.01).Compared with the 30th min,the recovery rate of dry matter was significantly decreased in each group(P<0.05).The number of lactic acid bacteria increased first and then decreased with the prolongation of fermentation time,which was the highest on the 10th day.Lactic acid content was significantly increased with the fermentation time(P<0.01).The pH value was significantly decreased with the prolongation of fermentation time(P<0.01).Our data indicated that the best fermen tation time was 6 days;the nutrient composition,in vitro digestibility,lactic acid content,and lactic acid bacteria number were at a good level;and the recovery rate of dry matter was higher under this fermentation conditions.