体外产气法研究不同饲粮中性洗涤纤维水平对瘤胃发酵参数的影响

Effect of different dietary neutral detergent fiber levels on rumen fermentation parameters by in vitro gas production

试验采用体外产气法研究不同日粮30 h中性洗涤纤维(dNDF30)水平对反刍动物瘤胃发酵的影响。在等能等氮(蛋白含量为16.5%)与中性洗涤纤维(NDF)水平为32%下分别配制dNDF30水平为16.4%、17.9%、19.4%、20.9%、22.4%、23.9%、25.4%和26.9%的日粮为发酵底物,分别为T_(1)组~T_(8)组,每组8个重复。结果显示,体外发酵24 h,T_(1)组的产气量(GP)显著低于其他各组(P<0.05)。体外发酵48 h,T_(5)组、T_(6)组、T_(7)组、T_(8)组GP显著高于其他处理组(P<0.05)。T_(8)组的体外干物质消失率(IVDMD)最高,显著高于T_(1)组、T_(2)组、T_(3)组、T_(4)组(P<0.05)。T_(8)组pH值显著低于其他各组(P<0.05)。T_(1)组氨态氮(NH_(3)-N)含量显著高于除T_(2)外的各组(P<0.05)。T_(1)组微生物蛋白(MCP)含量显著高于其他各组(P<0.05)。T_(8)组总挥发性脂肪酸含量最高,显著高于除T_(7)组、T_(6)组之外的各组(P<0.05)。T_(1)组乙酸含量显著高于除T_(2)组、T_(3)组、T_(4)组外各组(P<0.05)。T_(8)组丙酸含量显著高于T_(1)组、T_(2)组(P<0.05)。研究表明,较高日粮dNDF30水平有利于氨氮的利用和反刍动物瘤胃发酵。

The experiment was to study the effect of different dietary levels of dNDF30 on ruminant rumen fermentation by using method of gas production in vitro.Under the condition of equal energy nitrogen(16.5%protein content)and 32%NDF level,the diets with 16.4%,17.9%,19.4%,20.9%,22.4%,23.9%,25.4%and 26.9%levels of dNDF30 were prepared as fermentation substrates,respectively,they are groups T_(1) group to T_(8) group,each group was set with eight replicates.The results showed that after 24 h in vitro fermentation,the GP of T_(1) group was significantly lower than that of other groups(P<0.05).After 48 h in vitro fermentation,GP in T_(5) group,T_(6) group,T_(7) group and T_(8) group was significantly higher than that of other groups(P<0.05).The IVDMD of T_(8) group was the highest,which was significantly higher than that of T_(1) group,T_(2) group,T_(3) group and T_(4) group(P<0.05).The pH value of T_(8) group was significantly lower than that of other groups(P<0.05).The concentration of NH_(3)-N in T_(1) group was significantly higher than that in other groups except T_(2) group(P<0.05).The content of MCP in T_(1) group was significantly higher than that in other groups(P<0.05).The content of total volatile fatty acids in T_(8) group was significantly higher than that in other groups except T_(7) group and T_(6) group(P<0.05).The acetic acid content in T_(1) group was the highest,which was significantly higher than that in other groups except T_(2) group,T_(3) group and T_(4) group(P<0.05).The content of propionic acid in T_(8) group was significantly higher than that in T_(1) group and T_(2) group(P<0.05).The study indicates that higher dietary dNDF30 level is beneficial to utilization of ammonia nitrogen and ruminant rumen fermentation.