本试验旨在研究啤酒糟不同比例替代豆粕对水牛体外瘤胃发酵特性和甲烷生成的影响。采用压力读取式体外产气系统进行体外瘤胃发酵,啤酒糟分别以0、25%、50%、75%和100%(风干基础)替代发酵底物中的豆粕。测定培养72 h内产气量变化、培养24 h后可消化有机物含量、代谢能、氨态氮浓度、微生物蛋白质浓度和总挥发性脂肪酸浓度以及24 h甲烷产量变化。结果表明:1)72 h累积产气量、可消化有机物含量和代谢能均随啤酒糟替代比例的增加而呈降低趋势;72 h累积产气量0组、25%组、50%组显著高于75%组(P<0.05),极显著高于100%组(P<0.01)。2)氨态氮浓度25%组最高,极显著高于50%组和75%组(P<0.01);微生物蛋白质浓度0组最高,极显著高于75%组(P<0.01),显著高于100%组(P<0.05)。3)25%组总挥发性脂肪酸浓度最高,显著高于75%组和100%组(P<0.05)。4)6 h 0组、25%组和50%组甲烷产量显著低于75%组(P<0.05);12 h 75%组和100%组显著高于其他3组(P<0.05);24 h 75%组和100%组显著高于50%组(P<0.05),极显著高于0组和25%组(P<0.01)。综合而言,啤酒糟作为水牛蛋白质饲料以0~50%替代豆粕对体外瘤胃发酵特性和甲烷生成无不良影响。

The experiment was conducted to investigate the effects of substitution of soybean meal with distiller's grains at different ratios on rumen fermentation characteristics and methanogenesis of buffalo in vitro. A reading pressure system was used in the in vitro rumen fermentation, and soybean meal in the fermentation substrate was substituted with distiller's grains at ratios of 0, 25%, 50%, 75% and 100% (air-dry basis), respectively. Variation of gas production in 72 h, digestible organic matter content, metabolisable energy, concentrations of ammonia nitrogen, microbial protein and total volatile fatty acid after 24 h cultivation, as well as variation of methane production in 24 h were analyzed. The results showed as follows: 1) accumulation of gas production in 72 h, digestible organic matter content and metabolisable energy reduced with the increasing of substitution ratio of distiller's grains; accumulation of gas production in 72 h of groups 0, 25% and 50% was significantly higher than that of groups 75% (P<0.05) and 100% (P<0.01). 2) Concentration of ammonia nitrogen of group 25% was the highest and significantly higher than that of groups 50% and 75% (P<0.01); concentration of microbial protein of group 0 was the highest and significantly higher than that of groups 75% (P<0.01) and 100% (P<0.05). 3) Concentration of total volatile fatty acids of group 25% was the highest and was significantly higher than that of groups 75% and 100% (P<0.05). 4) Methane production of groups 0%, 25% and 50% at 6 h was significantly higher than that of group 75% (P<0.05); the methane production of groups 75% and 100% at 12 h was significantly higher than that of the other three groups; the methane production of groups 75% and 100% at 24 h was significantly higher than that of groups 50% (P<0.05), 0% (P<0.01) and 25% (P<0.01). In conclusion, distiller's grains can be used as a protein feed for buffalo, and substitution of soybean meal with distiller's grains at ratios of 0 to 50% has no negative effect on rumen fermentation characteristic and methanogenesis.