摘要
试验旨在探究发酵时间对苜蓿青贮常规营养物质、发酵指标、瘤胃体外发酵产气量及菌群结构的影响。苜蓿干草分别发酵0、60、90及120 d,测定其各项常规营养物质、挥发性脂肪酸(VFA)含量、发酵底物累积产气量及瘤胃菌群结构。结果显示,粗脂肪含量随发酵时间显著上升(P<0.05),中性洗涤纤维和粗灰分含量均随发酵时间显著下降(P<0.05)。90 d和120 d时的体外发酵48 h累积产气量显著低于60 d(P<0.05)。发酵底物在该产气速率下的理论最大产气量随发酵时间增加而下降,且90 d和120 d显著低于60 d(P<0.05),120 d的底物发酵产气过程中的曲线拐点参数显著高于60 d(P<0.05)。发酵120 d苜蓿青贮达到最大产气速率所需的时间和达到底物最大降解率所需的时间显著高于60 d(P<0.05)。发酵60 d的最大产气速率和底物最大降解率显著高于其他时间(P<0.05)。除乙酸外,各VFA及总VFA的产量均在发酵60~90 d时显著降低(P<0.05),在90~120 d时显著回升(P<0.05)。在门水平上,发酵90 d的苜蓿青贮经体外发酵后,瘤胃液中放线菌门相对丰度显著高于60 d和120 d(P<0.05)。在属水平上,随着发酵时间的增加,解琥珀酸菌属的相对丰度逐渐降低。研究表明,发酵120 d的苜蓿青贮常规营养物质含量及饲用品质最佳。
The experiment aims to explore the effects of fermentation time on the conventional nutrients,fermentation index,rumen in vitro fermentation gas production,and microbial community structure of alfalfa silage.Alfalfa hay was fermented for 0,60,90 and 120 days respectively,and the contents of conventional nutrients,volatile fatty acids(VFA),cumulative gas production of fermentation substrates,and rumen flora structure were determined.The results showed that crude fat significantly increased with fermentation time(P<0.05).Both neutral detergent fiber and crude ash content showed a significant decreasing trend with fermentation time(P<0.05).The cumulative gas production after 48 hours of in vitro fermentation at 90 and 120 days was significantly lower than that at 60 days(P<0.05).The theoretical maximum gas production of the fermentation substrate at this gas production rate decreased with the increase of fermentation time,and was significantly lower at 90 and 120 days than at 60 days(P<0.05).The curve inflection point parameter of the substrate fermentation gas production process at 120 days was significantly higher than that at 60 days(P<0.05).The time required to reach the maximum gas production rate and substrate degradation rate of alfalfa silage after 120 days of fermentation were significantly higher than those after 60 days(P<0.05).The maximum gas production rate and substrate degradation rate at 60 days of fermentation were significantly higher than those at other times(P<0.05).Except for acetic acid,the production of various VFA and total VFA significantly decreased at 60~90 days of fermentation(P<0.05),and significantly increased at 90~120 days(P<0.05).At the phylum level,the relative abundance of Actinobacteria in rumen fluid of alfalfa silage fermented for 90 days after in vitro fermentation was significantly higher than that at 60 and 120 days(P<0.05).At the genus level,the relative abundance of Actinobacillus succinogenes gradually decreases with increasing fermentation time.The research shows that alfalfa silage fermented for 120 days has the best conventional nutrient content and feeding quality.
作者
胡羽飏
雒诚龙
王中汉
王倩倩
赵丽伟
伍振越
庄巧越
王蔚
HU Yuyang;LUO Chenglong;WANG Zhonghan;WANG Qianqian;ZHAO Liwei;WU Zhenyue;ZHUANG Qiaoyue;WANG Wei
出处
《饲料研究》
北大核心
2025年第11期112-117,共6页
Feed Research
基金
国家重点研发计划青年科学家项目(项目编号:2022YFD130001400)。
关键词
苜蓿青贮
发酵时间
营养品质
发酵品质
体外产气法
alfalfa silage
fermentation time
nutritional quality
fermentation quality
in vitro gas production method
