松针对体外瘤胃发酵特性的影响

Effect of pine needles on rumen fermentation characteristics in vitro

试验采用体外产气法探讨松针对体外瘤胃发酵的影响。以松针和玉米青贮作为瘤胃体外发酵底物,按干物质基础计,松针在发酵底物中所占比例分别为0(对照组)、5%(试验Ⅰ组)、10%(试验Ⅱ组)、15%(试验Ⅲ组),培养48 h后,测定瘤胃发酵参数。结果显示,各处理组间发酵液pH值差异不显著(P>0.05);试验Ⅲ组氨态氮、微生物蛋白浓度显著低于其他组(P<0.05)。试验Ⅲ组的总挥发性脂肪酸、乙酸和丙酸浓度均显著低于其他组(P<0.05);各组乙酸/丙酸在2.38~2.49。试验Ⅲ组产气量显著低于对照组(P<0.05);干物质降解率显著低于其他组(P<0.05)。研究表明,松针占发酵底物15%时,发酵液中氨态氮浓度、挥发性脂肪酸浓度、产气量和干物质降解率显著降低。

The experiment was conducted to evaluate the effect of pine needles on rumen fermentation parameters in vitro by gas production technique in vitro.Pine needles and corn silage were employed as fermentation substrates,the proportions of pine needles in the fermentation substrates(dry matter basis)were 0(control group),5%(groupⅠ),10%(groupⅡ)and 15%(groupⅢ).Rumen fermentation parameters were determined after being fermented for 48 h.The results showed that the pH value of the fermentation fluid showed no significant differences among all groups(P>0.05).The concentration of ammonia nitrogen and microbial protein in the groupⅢwas significantly lower than that in other groups(P<0.05).The concentration of total volatile fatty acids,acetic acid and propionic acid in the groupⅢwas significantly lower than that in other groups(P<0.05).The ratio of acetic acid to propionic acid ranged from 2.38~2.49.Gas production in the groupⅢwas significantly lower than that in the control group(P<0.05).The dry matter degradation rate of the groupⅢwas significantly lower than that of other groups(P<0.05).The study indicates that the concentration of ammonia nitrogen,volatile fatty acids,gas production and dry matter degradation rate in the fermentation fluid are significantly reduced when pine needles is 15%of the fermentation substrate.