白酒糟饲料化利用菌种的筛选及工艺优化

Screening and process optimization of bacteria for fodder utilization of distiller’s grains

试验旨在探索改善酱香型白酒糟营养价值的发酵菌种组合和固态发酵工艺及白酒糟在羔羊中的应用效果。以酱香型白酒糟为单一发酵基质,使用6种微生物菌种的8个组合进行固态发酵,利用正交试验设计对发酵底物水分、发酵温度和发酵时间等条件进一步优化,在生产车间进行固态发酵放大测试,对相关营养指标和霉菌毒素进行检测。将27头体重和日龄相近的断奶母羔羊随机分为3组,每组3个重复,每个重复3只羊。对照组为基础日粮;试验Ⅰ组为基础日粮+50 g/d酱香型发酵酒糟(MFFDG);试验Ⅱ组为基础日粮+150 g/d MFFDG。试验期13 w。结果显示:8个菌种组合均能够显著提升白酒糟中的真蛋白含量(P<0.05),提升效果较好的是E组(0.10%酿酒酵母+0.20%产朊假丝酵母+0.05%枯草芽孢杆菌+0.05%黑曲霉+0.05%米曲霉)、G组(0.10%酿酒酵母+0.05%黑曲霉+0.05%米曲霉)和F组(0.10%酿酒酵母+0.25%产朊假丝酵母+0.05%枯草芽孢杆菌+0.05%地衣芽孢杆菌+0.05%黑曲霉+0.05%米曲霉)。最佳发酵工艺为38℃、55%含水量发酵5 d。标准化车间生产后酱香型白酒糟中的真蛋白、粗蛋白、钙含量较发酵前显著提升(P<0.05);粗纤维和有机物含量较发酵前显著降低(P<0.05);呕吐毒素较发酵前显著提升(P<0.05),但含量远低于饲料生产的限定水平。将发酵酒糟用于饲喂断奶羔羊可以显著提升平均日增重(P<0.05),降低料重比(P<0.05),而对平均日采食量无显著影响(P>0.05)。研究表明,酿酒酵母、黑曲霉、米曲霉组合及优化条件,可以显著提升白酒糟的营养价值。基础日粮中添加MFFDG可以有效提升断奶羔羊的生产性能。

The study was to explore the combination of fermentation strains and solid-state fermentation technology to improve the nutritional value of Maotai-flavor liquor grains and the application effect of distiller’s grains on lambs.Using Maotai-flavor liquor lees as a single fermentation substrate,using eight combinations of six microbial strains for solidstate fermentation,using orthogonal experiment design to further optimize the conditions of the fermentation substrate moisture,fermentation temperature and fermentation time,to carry out solid-state fermentation scale-up test in production workshop,and the relevant nutritional indicators and mycotoxins were detected.27 weaned female lambs with similar body weight and age were randomly divided into three groups,with three replicates in each group and three lambs in each replicate.The lambs in control group were fed with a basal diet,the lambs in groupⅠwere fed with a basal diet+50 g/d MFFDG,and the lambs in groupⅡwere fed with a basal diet+150 g/d MFFDG.The experiment lasted for 13 w.The results showed that the eight strains combinations could significantly increase the true protein content in distiller’s grains(P<0.05).Group E(0.10%S.cerevisiae+0.20%C.utilis+0.05%B.subtilis+0.05%A.niger+0.05%A.oryzae),group G(0.10%S.cerevisiae+0.05%A.niger+0.05%A.oryzae)and group F(0.10%S.cerevisiae+0.25%C.utilis+0.05%B.subtilis+0.05%B.licheniformis+0.05%A.niger+0.05%A.oryzae)had the better improvement effect.The optimum fermentation process was 38℃with 55%water content for 5 d.The content of true protein,crude protein and calcium in Maotai-flavor distiller’s grains were significantly increased(P<0.05),and the contents of crude fibre and organic matter were significantly decreased(P<0.05)compared with those before fermentation,and emetic toxin was significantly increased compared with before fermentation(P<0.05),but the content was far lower than the limit level of feed production.Feeding fermented lees to weaned lambs could significantly increase average daily gain(P<0.05)and decrease feed to gain ratio(P<0.05),but it had no significant effect on average daily feed intake(P>0.05).The experiment indicates that the combination of S.cerevisiae,A.niger and A.oryzae and the optimized conditions can significantly improve the nutritional value of white distiller’s grains.Adding MFFDG in basal diet can effectively improve the performance of weaned lambs.