蛋氨酸羟基类似物异丙酯对瘤胃体外发酵参数的影响

本试验利用体外产气法研究蛋氨酸羟基类似物异丙酯(HMBi)对瘤胃发酵参数的影响.试验分为3个组,分别为对照组、试验1组和试验2组.其中,2个试验组的培养管中分别加入干物质量1％和2％的HMBi.分别在培养至3、6、9、12、24 h时测定产气量,培养12、24 h后测定发酵液pH以及挥发性脂肪酸和乳酸浓度.结果表明:12 h时2个试验组的乙酸、丁酸、异戊酸和总挥发性脂肪酸浓度均显著高于对照组(P＜0.05),但2个试验组间差异不显著(P＞0.05);24 h时各挥发性脂肪酸以及总挥发性脂肪酸浓度试验各组间均无显著差异(P＞0.05).试验各组的pH在12、24 h时均处于正常范围,12 h时pH试验1组高于对照组(P＞0.05)和试验2组(P＜0.05);而24 h时pH试验各组间均无显著差异(P＞0.05).24 h时2个试验组的乳酸浓度均高于对照组,且差异显著(P＜0.05),但2个试验组间差异不显著(P＞0.05).3、6、12 h时2个试验组的产气量均高于对照组,且差异显著(P＜0.05),但2个试验组间差异不显著(P＞0.05).由此得出,在发酵底物中添加HMBi可改善瘤胃体外发酵.

Influence of 2-Hydroxy-4-(Methylthio) Butanoic Acid Isopropyl Ester on Rumen Fermentation Parameters in Vitro

This study was conducted to investigate the influence of 2-hydroxy-4-(methylthio) butanoic acid isopropyl ester(HMBi) on rumen fermentation parameters in vitro.There were 3 groups(control group,trial groups 1 and 2) in the trial,and culture tubes in trial groups 1 and 2 were added with 1% and 2% HMBi(DM basis),respectively.The gas production of fermentation broth was measured after cultured for 3,6,9,12 and 24 h.The concentrations of volatile fatty acid(VFA) and lactic acid,and pH of fermentation broth were measured after cultured for 12 and 24 h.The results showed that the concentrations of acetate,butyrate,isovalerate and total VFA at 12 h in trial groups were significantly higher than those in the control group(P<0.05),but there were no significant differences between the trial groups(P>0.05).No significant differences were observed in concentrations of proportions of VFA and total VFA at 24 h among all groups(P>0.05).The pH at 12 and 24 h in all groups were in normal range,and pH at 12 h in trial group 1 was higher than that in control group(P>0.05) and trial group 2(P<0.05),while the pH at 24 h was no significant difference among all groups(P>0.05).The lactic acid concentration at 24 h in trial groups was significantly higher than that in the control group(P<0.05),but there was no significant difference between the trial groups(P>0.05).The gas production at 3,6 and 12 h in trial groups was higher than that in the control group(P<0.05),but there was no significant difference between the trial groups(P>0.05).In conclusion,the rumen fermentation can be improved by supplementation of HMBi.