尿素添加对青贮品质影响的Meta分析研究

Meta-Analysis Study of the Effects of Adding Urea on Silage Quality

本研究通过对尿素添加青贮的中外文文献进行Meta分析,旨在为尿素添加青贮饲料标准化制作和青贮品质提升提供理论依据。通过检索中国知网和Web of Science等文献数据库,依据纳入排除标准,纳入104篇文献,最终得到共349组尿素青贮数据,研究发现尿素添加对青贮饲料的粗蛋白(Crude protein,CP)含量影响显著(P<0.05),CP含量提高了38.542%;同时显著提高了体外干物质(Dry matter,DM)、有机质(Organic matter,OM)及中性洗涤纤维(Neutral detergent fiber,NDF)消化率(P<0.05),显著降低了青贮饲料的纤维含量和体外甲烷产量(P<0.05)。尿素添加一定程度上降低了青贮饲料的发酵品质,但可促进乳酸菌的积累、抑制青贮过程中酵母菌、霉菌等腐败微生物的生长,并且使青贮饲料有氧稳定性时间显著提升46.521%(P<0.05)。尿素添加青贮的影响因子亚组分析综合评价确定尿素单独添加适宜的青贮原料种类是水果副产品,适宜的尿素添加量范围为0.9%~1.2%,适宜尿素添加青贮时间是45~60 d或≥60 d。

This study conducted a meta-analysis on the domestic and foreign literatures regarding the addition of urea to silage,to provides insights for standardizing production processes and enhancing the quality of urea-added silage.By searching databases such as China National Knowledge Infrastructure and Web of Science,104 articles were incorporated based on inclusion and exclusion criteria,yielding a total of 349 sets of urea-silage data.The results indicated that urea addition had a significant effect on the crude protein(CP)content of silage(P<0.05),which increased by 38.542%.It also significantly increased in vitro dry matter(DM),organic matter(OM)and neutral detergent fiber(NDF)digestibility(P<0.05),and significantly decreased the fiber content and in vitro methane production(P<0.05).The addition of urea marginally reduced the fermentation quality of silage,but promoted the accumulation of lactic acid bacteria,inhibited the growth of spoilage microorganisms such as yeasts and molds during ensiling,and significantly extended the aerobic stability time of silage by 46.521%(P<0.05).Subgroup analysis and comprehensive evaluation of influencing factors determine appropriate silage raw material for urea addition as fruit by-products,with suitable urea amounts of 0.9%~1.2%and silage times of 45~60 or≥60 days.