柠檬酸添加剂对圆叶决明青贮饲料营养品质与发酵特性的影响

Effects of citric acid addition on nutritional quality and fermentation characteristics of Chamaecrista rotundifolia silage

以圆叶决明(Chamaecrista rotundifolia)作为原料,分别添加0(CK)、0.1%(Ⅰ组)、0.3%(Ⅱ组)、0.5%(Ⅲ组)、1.0%(Ⅳ组)柠檬酸(citric acid,CA)进行青贮调制,青贮时间分别为30、45和60 d,对圆叶决明青贮营养成分和发酵品质进行测定分析,旨在探究CA和发酵时间对圆叶决明青贮品质的影响。结果表明:1)CA对圆叶决明青贮料干物质(dry matter,DM)和水溶性碳水化合物(water soluble carbohydrates,WSC)含量影响较小;2)试验组粗蛋白(crude protein,CP)和乳酸(lactic acid,LA)含量显著高于CK组(P<0.05),中性洗涤纤维(neutral detergent fiber,NDF)、酸性洗涤纤维(acid detergent fiber,ADF)和丙酸(propionic acid,PA)含量、pH、氨态氮/总氮(NH3-N/TN)显著低于CK组(P<0.05),Ⅲ组和Ⅳ组效果更佳,但Ⅲ组的乙酸(acetic acid,AA)含量显著低于其他组(P<0.05);3)CA和发酵时间的交互作用对NDF和ADF含量、NH3-N/TN及PA含量影响显著(P<0.05),对其他营养指标和发酵指标无显著影响(P>0.05)。综上所述,不同CA水平及发酵时间对圆叶决明青贮营养品质和发酵特性均有改善作用。其中,青贮时间为30 d、CA添加量为0.5%(FM)时改善效果最佳。

The objective of this study was to investigate the effect of citric acid(CA)and fermentation time on the fermentation quality of Chamaecrista rotundifolia silage.Chamaecrista rotundifolia was used as the raw material and the treatments were the addition of 0(CK),0.1%(groupⅠ),0.3%(groupⅡ),0.5%(groupⅢ),and 1.0%(groupⅣ)CA to silage for 30,45,and 60 days.After the silage process,samples were taken to measure and analyze the nutrient composition and fermentation quality of Chamaecrista rotundifolia silage.The results showed that 1)CA had little influence on the dry matter(DM)and water soluble carbohydrate(WSC)contents of Chamaecrista rotundifolia silage.2)The crude protein(CP)and lactic acid(LA)contents of the experimental groups were significantly higher than those in CK(P<0.05).The detergent fiber(NDF),acid detergent fiber(ADF),and propionic acid(PA)contents,pH,and the NH3-N/TN ratio of the experimental groups were significantly lower than those for CK(P<0.05),and the effects of groupsⅢandⅣwere better than the other experimental groups.However,the acetic acid(AA)content in groupⅢwas significantly lower than that in the other treatment groups(P<0.05).3)The interaction effect between the CA additive and fermentation time had significant effects on the NDF,ADF,NH3-N/TN,and PA contents(P<0.05),but had no significant effects on other nutrient and fermentation indexes(P>0.05).In conclusion,different CA levels and different fermentation times can improve the nutrient quality and fermentation characteristics of Chamaecrista rotundifolia silage and the best improvement effect was observed when the CA supplemental level was 0.5%(FM)for silage at 30 days.