赖氨酸添加水平对高精料日粮体外瘤胃发酵特性的影响

Effect of Lysine Supplementation Level on In Vitro Rumen Fermentation Characteristics in High-concentrate Diet

试验旨在探究不同赖氨酸(lysine,Lys)添加水平对高精料日粮体外瘤胃发酵特性的影响。试验设置5个组,分别添加0、0.05%、0.10%、0.20%和0.40%的Lys,每个组5个重复,其中0添加作为对照组,体外发酵48 h后收集发酵液用以检测瘤胃发酵参数,并采用多项指标综合指数(MFAEI)对添加效果进行综合评估。结果发现:①添加Lys对12、24、36、48 h产气量以及有机物消化率均无显著影响(P>0.05),0.05%、0.10%、0.20%添加组的甲烷产量显著高于0.40%添加组(P<0.05);②添加Lys显著提高了发酵液的pH(P<0.05),0.05%、0.10%、0.20%添加组的乙酸、丙酸、丁酸、戊酸和总挥发性脂肪酸的含量显著高于0.40%添加组(P<0.05),0.10%、0.20%添加组的异戊酸含量显著高于0、0.40%添加组(P<0.05);③MFAEI分析发现,添加0.20%的Lys对体外瘤胃发酵参数的改善效果最好。本试验结果表明,高精料日粮中添加0.20%的Lys可以改善瘤胃发酵。

This experiment was conducted to investigate the effect of different lysine(Lys)supplementa⁃tion levels on in vitro rumen fermentation characteristics of high-concentrate diet.Five groups were set up with Lys 0,0.05%,0.10%,0.20%,and 0.40%,with five replicates in each group,and 0 of Lys was designated as the control group.After 48 h in vitro fermentation,fermented rumen fluid was col⁃lected to determine rumen fermentation character⁃istics,and the multiple-factors associative effects index(MFAEI)was taken to evaluate the benefits of Lys supplementation on rumen fermentation characteristics.The results showed that:①Lys supplementation had no significant effects on gas production at 12,24,36 h and 48 h,and organic matter digestibility compared with control group(P>0.05),whilst methane production in groups 0.05%,0.10%,and 0.20%were significantly higher than that in group 0.40%(P<0.05).②Lys supplementation significantly increased the pH value of fermented ru⁃men fluid(P<0.05),and the concentrations of acetate,propionate,butyrate,valerate,and total volatile fat⁃ty acids in groups 0.05%,0.10%,and 0.20%were significantly higher than those in group 0.40%(P<0.05).Moreover,the isovalerate concentration in 0.10%and 0.20%groups were significantly higher than that in 0 and 0.40%groups(P<0.05);③MFAEI analysis showed that supplementing with 0.20%of Lys had the best benefits to improving in vitro rumen fermentation characteristics.These results indicate that supplementing with 0.20%of Lys could benefit rumen fermentation in high-concentrate diet.