酸中毒条件下添加阿卡波糖对瘤胃微生物发酵的影响

Effect of acarbose addition on acute and subacute rumen acidosis in an in vitro fermentation study

利用体外培养技术,评估了急性与亚急性酸中毒条件下添加阿卡波糖对瘤胃微生物发酵的影响。设3个实验,实验1和实验2体外摸拟了亚急性酸中毒(5.0<pH<5.6)、实验3模拟了急性酸中毒条件(pH<5.0),各实验中阿卡波糖添加量均为0,0.1,0.2和0.4mg/mL。实验1中底物组成为0.8g玉米和0.2g粉碎羊草,实验2以高粱、玉米、小麦和大麦为底物,实验3发酵底物为0.75g玉米、0.25g纤维二糖、0.25g甘露糖和0.25g木糖;各实验组均设4个重复,体外培养24h。结果表明,实验1中,较对照组相比,阿卡波糖处理组的pH值、乙丙比、异丁酸和戊酸浓度显著升高(P<0.001),乙酸、丙酸、丁酸、总挥发性脂肪酸(total volatile fatty acid,TVFA)、乳酸浓度和累积产气量皆显著降低(P<0.01),但异戊酸浓度变化不显著(P=0.794);实验2中,较对照组相比,添加阿卡波糖提高了4种底物下发酵液的pH值和氨氮浓度(P<0.01),降低了发酵体系中的乙酸、丙酸、异丁酸、丁酸、异戊酸、戊酸和TVFA浓度,提高了乙丙比(P<0.01),除乙酸和TVFA外,对上述其他指标,日粮与阿卡波糖间存在显著的互作效应(P<0.01)。实验3中,与对照相比,添加阿卡波糖显著提高了发酵液pH值、氨氮、丙酸、丁酸和戊酸浓度(P<0.01),降低了乳酸和乙丙比(P<0.05),但对乙酸、异丁酸、异戊酸和TVFA浓度无显著影响(P>0.05)。结果说明阿卡波糖可有效提高发酵体系中的pH值,降低乳酸浓度,预防瘤胃酸中毒。

The effect of acarbose addition on ruminant fermentation was investigated in three experiments.In the first and second experiments,the effects of acarbose addition on subacute rumen acidosis was studied.The final concentration of acarbose in the media was 0,0.1,0.2 or 0.4 mg/mL.In the first study,the substrate consisted of 0.8 g cracked corn and 0.2 g Chinese dry grass.As compared with the control,the acarbose addition increased the pH value and the ratio of acetate to propionate,and decreased acetate,propionate,butyrate,isobutyrate,total volatile fatty acid and lactic acid concentrations.In the second experiment,the substrates consisted of cracked sorghum,corn,barley and wheat.The acarbose supplement increased pH,NH3-N,lactate concentration and the ratio of the acetate to propionate,and decreased acetate,propionate,butyrate and TVFA concentration.In the third experiment,the effect of acarbose addition on acute rumen acidosis was investigated,the pH,acetate,propionate,acetate,propionate,valerate,isovalerate and TVFA concentrations were reduced by acarbose addition,while the pH value was improved.There were no significant changes in the isobutyrate,butyrate,and isovalerate concentrations.In general,these results indicated that acarbose addition increased the pH value and reduced lactic acid concentration,and it has the potential to prevent rumen acidosis.