饲粮中结构性碳水化合物与非结构性碳水化合物的不同比例对降解后白酒糟体外发酵特性的影响(英文)

Effects of Different Dietary SC/NSC Ratios on in vitro Fermentation Characteristics of Degraded Distilled Grain

本文旨在研究添加可溶性淀粉对降解后的白酒糟体外发酵特性的影响,并确定影响发酵的最佳结构性碳水化合物(SC)与非结构性碳水化合物(NSC)的比例。采用黄孢原毛平革菌发酵白酒糟20d,以降解其木质素含量。在体外发酵各组中添加可溶性淀粉使SC/NSC比分别为1.66、2.06、2.46、2.86、3.26和3.66。每组设5个重复。结果表明,通过黄孢原毛平革菌发酵,白酒糟中酸性洗涤木质素的含量降低了16.4%(P<0.01),而粗蛋白质含量提高了6.04%(P<0.01)。在体外发酵试验中,随着可溶性淀粉添加量的增加,累计产气量显著增加(P<0.01)。增加可溶性淀粉添加量改变SC/NSC比可显著影响微生物蛋白(MCP)、总挥发性脂肪酸(TVFA)和氨氮(NH3-N)浓度(P<0.01)。通过SC/NSC比(x)与MCP(y)的回归分析(y=-0.826x2+3.947x+1.189)得出,体外发酵最佳SC/NSC比为2.39。添加可溶性淀粉提高了丙酸在TVFA中的比例(P<0.05),而降低了乙酸与丙酸比例(P<0.05)。由结果可知,添加可溶性淀粉可提高降解后白酒糟的消化率,并得出体外发酵最佳SC/NSC比为2.39。

The aim of this study was to evaluate the effects of adding soluble starch on the in vitro fermentation characteristics of degraded distilled grain,and to determine the optimal ratio of structural carbohydrate（SC）to nonstructural carbohydrate（NSC）for in vitro fermentation of degraded distilled grain.The distilled grain was degraded by Phanerochaete chrysosporium for 20 days to reduce the content of lignin.The ratios of SC/NSC were designed as 1.66,2.06,2.46,2.86,3.26 and 3.66 by adding different amounts of soluble starch into each group of in vitro fermentation.Each group had 5 replicates.The results showed that after degrading by Phanerochaete chrysosporium,the acid detergent lignin（ADL）of distilled grain was reduced by 16.4%（P0.01）and the content of crude protein was increased by 6.04%（P0.01）.In the experiment of in vitro fermentation,the cumulative gas production（GP）was significantly increased（P0.01）with the levels of soluble starch increasing.Adding soluble starch to change the SC/NSC ratio could significantly affect the microbial protein（MCP）,total volatile fatty acid（TVFA）,and ammonia nitrogen concentrations（P0.01）.Through regression analysis of SC/NSC ratio（x）and MCP（y）（y=―0.826x2＋3.947x＋1.189）,the optimal SC/NSC ratio was 2.39.Adding soluble starch could significantly increase the propionate/TVFA ratio（P0.05）,but reduce the acetate/propionate ratio（P0.05）.These results indicated that adding soluble starch could improve the digestibility of degraded distilled grain,and the optimal SC/NSC ratio for in vitro fermentation was 2.39.