体外法研究丝兰皂苷对瘤胃发酵参数的影响

Effects of Yucca Schidigera on Rumen Fermentation Parameters in Vitro

试验旨在探讨添加不同剂量的丝兰皂苷(YS)对瘤胃体外发酵参数的影响。试验采用完全随机试验设计,以0.5g全混合日粮(TMR)作为发酵底物,添加0、1、5、25和125g/kg TMR的YS,每个处理6个平行,分别通过AGRS-III微生物发酵微量产气自动记录仪和恒温箱在39℃条件下进行30h体外发酵。结果表明:(1)与对照组相比,25和125g/kg剂量组显著提高了总产气量(P<0.05),25g/kg剂量组显著提高了理论最大产气量(P<0.05);(2)25和125g/kg剂量组的体外干物质降解率,中性洗涤纤维降解率和酸性洗涤纤维降解率均显著高于其他处理组(P<0.05),氨氮浓度显著低于其他处理组(P<0.05);(3)25和125g/kg剂量组显著提高了体外连续培养30h发酵液中的乙酸、丙酸和总挥发性脂肪酸浓度(P<0.05)。由此可见,体外试验TMR中添加25和125g/kg的YS能够促进瘤胃发酵。

In order to investigate the effects of Yucca Schidigera(YS)on fermentation parameters in vitro,five treatments consisted of supplemental YS at 0,1,5,25 and 125g/kg(six replicates per treatment)were assigned randomly to 6of 30 incubation bottles together with 0.5g TMR,50 mL basal media and 25 mL rumen fluid obtained from three rumen-cannulated lactating Holstein dairy cows.Three culture flasks of each treatment were incubated in automated trace gas recording system(AGRS-III,Beijing)at 39℃for 30 h.And others were cultured at 39℃shaking incubator for 30 hin vitro.Results showed that YS at 25 and 125g/kg improved total gas production(GP,P<0.05),in vitro dry matter degradability(IVDMD,P<0.05),neutral detergent fiber degradation rate(DNDF,P<0.05)and acid detergent fiber degradation rate(DADF,P<0.05);YS decreased the concentration of NH3-N(P<0.05),with the increasing dose of YS.Compared with other treatments,after 30 hincubation,the acetate,propionate,and total volatile fatty acids(TVFA)increased significantly(P<0.05).Therefore,YS was beneficial to manipulate rumen fermentation in vitro.