阴离子饲粮对活体外瘤胃发酵特性和营养物质消化的影响

应用双外流连续培养系统模拟瘤胃发酵,研究不同阴阳离子差(DCAD)水平的阴离子饲粮对活体外瘤胃发酵和营养物质消化率的影响。试验分2期进行,每期12个发酵罐,3个1组,分别投入4种不同DCAD水平的饲粮:+120-、9-、77-、145 mEq/kgDM,后3种饲粮通过添加阴离子添加剂降低DCAD。结果表明:①阴离子饲粮对瘤胃发酵pH值、氨态氮浓度、总挥发性脂肪酸浓度、主要挥发酸的摩尔比例均没有显著影响(P>0.2)。②对饲粮干物质、有机质、中性洗涤纤维、粗蛋白消化率没有显著影响(P>0.2)。③对瘤胃微生物合成效率没有显著影响(P>0.2)。试验结论为阴离子饲粮对活体外瘤胃发酵和饲粮营养物质消化率没有显著影响。

Influence of Anionic Close-up Diets on Rumen Fermentation and Ruminal Digestion Characteristics in Continuous Culture

This study was conducted to investigate the different levels of dietary cation-anion difference of anionic close-up diet on rumen fermentation and ruminal digestion characteristics in a dual-flow continuous culture system.Diets were formulated with four DCAD levels(+120,-9,-77,-145 mEq/kg DM) by adding different levels of anionic salts in diets of strongly negative DCAD.The results showed that ① ruminal fermentation parameters including rumen pH,concentrations of ammonia nitrogen and total VFA,and individual VFA molar percentages,except isovaleric,were unaffected(P > 0.2);② no differences were found in rumen digestion of OM,DM,CP and NDF by DCAD levels(P > 0.2);③no differences(P > 0.2) were observed in microbial yield and protein synthetic efficiency among treatments.In conclusion,adding different levels of anionic salts to reduce DCAD did not affect the rumen fermentation and ruminal digestions in vitro.