蒸汽爆破和蒸汽爆破+发酵处理对甘蔗渣营养成分、体外瘤胃发酵特征和甲烷产量的影响

Effects of Steam Explosion and Steam Explosion+Fermentation on Nutritional Components,in Vitro Rumen Fermentation Characteristics and Methane Production of Bagasse

本试验旨在研究蒸汽爆破和蒸汽爆破+发酵处理对甘蔗渣营养成分、体外瘤胃发酵特征和甲烷(CH_(4))产量的影响。将甘蔗渣分别进行蒸汽爆破和蒸汽爆破+发酵处理,设置对照组(CK组,未处理的甘蔗渣)、蒸汽爆破组(SE组,蒸汽爆破处理的甘蔗渣)、蒸汽爆破+发酵组(SE+F组,蒸汽爆破+发酵处理的甘蔗渣),每组3个重复。3组甘蔗渣分别进行常规营养成分和碳水化合物组分的测定分析,并选用湘东黑山羊作为瘤胃液供体动物进行体外瘤胃发酵试验(72 h)。结果表明:与CK组相比,SE组甘蔗渣的中性洗涤可溶物、可溶性碳水化合物和总糖含量显著提高(P<0.05);体外瘤胃发酵干物质降解率、中性洗涤纤维(NDF)降解率、总挥发性脂肪酸浓度和乙酸/丙酸显著提高(P<0.05),8~72 h产气量和CH_(4)产量明显提高。与SE组相比,SE+F组甘蔗渣的粗蛋白质、真蛋白质和中性洗涤可溶物含量显著提高(P<0.05),半纤维素、NDF和酸性洗涤纤维含量显著降低(P<0.05);体外瘤胃发酵总挥发性脂肪酸浓度、乙酸/丙酸显著降低(P<0.05),8~72 h产气量和CH_(4)产量明显降低,氨态氮含量显著提高(P<0.05)。综上所述,蒸汽爆破处理能够提高甘蔗渣可溶性碳水化合物含量,生成更多单糖,促进甘蔗渣在体外瘤胃发酵过程中的降解,增加总挥发性脂肪酸浓度;蒸汽爆破后再对甘蔗渣进行微生物发酵,可促进瘤胃微生物蛋白合成,减少CH_(4)产量。

This study was conducted to investigate the effects of steam explosion and steam explosion+fermentation on nutritional components,in vitro rumen fermentation characteristics and methane(CH_(4))production of bagasse.Bagasse was treated with steam explosion and steam explosion+fermentation,and 3 groups were designed:control group(CK group,untreated bagasse),steam explosion group(SE group,steam explosion treated bagasse)and steam explosion+fermentation group(SE+F group,steam explosion+fermentation treated bagasse),each group contained 3 replicates.The conventional nutritional components and carbohydrate composition of bagasse in the 3 groups were analyzed,and the Xiangdong black goat was selected as rumen fluid donor animal for 72 h in vitro rumen fermentation trial.The results show that compared with CK group,the contents of neutral detergent soluble,water soluble carbohydrate and total sugar in bagasse of SE group were significantly increased(P<0.05);the in vitro rumen fermentation dry matter degradation rate,neutral detergent fiber(NDF)degradation rate,total volatile fatty acid concentration and acetate to propionate ratio were significantly increased(P<0.05),and the gas production and CH_(4)production during 8 to 72 h were obvious improved.Compared with SE group,the contents of crude protein,true protein and neutral detergent soluble in bagasse of SE+F group were significantly increased(P<0.05),and the contents of hemicellulose,NDF and acid detergent fiber were significantly decreased(P<0.05);the in vitro rumen fermentation total volatile fatty acid concentration and acetate to propionate ratio were significantly decreased(P<0.05),the gas production and CH_(4)production during 8 to 72 h were obvious decreased,and the ammonia nitrogen content was significantly increased(P<0.05).In summary,the steam explosion treatment can increase water soluble carbohydrate content of bagasse,and release more monosaccharide,promote the degradation of bagasse and improve the total volatile fatty acids concentration during in vitro rumen fermentation.Microbial fermentation of bagasse after steam explosion can promote the rumen microbial protein synthesis and reduce the CH_(4)production.