饲粮精粗比对南江黄羊瘤胃体外发酵的影响

Forage to Concentrate Ratio: Effects on Rumen Fermentation in Nanjiang Brown Goats in Vitro

本试验旨在研究饲粮不同精粗比对南江黄羊瘤胃体外发酵的影响。试验以3只装有永久性瘤胃瘘管的健康南江黄羊[平均体重为(25.48±1.48)kg]作为瘤胃液供体动物,采用单因素试验设计,试验饲粮精粗比分别为10∶90(10C组)、30∶70(30C组)、50∶50(50C组)、70∶30(70C组)、90∶10(90C组)。结果表明:随着饲粮精粗比的提高,培养液中pH逐渐下降,发酵后70C、90C组均显著低于10C、30C组(P<0.05);精粗比对氨态氮浓度和总挥发性脂肪酸浓度影响不显著(P>0.05);微生物蛋白浓度随着精粗比的提高逐渐升高,其中90C组显著高于其他4组(P<0.05);有机物发酵率随着精粗比的提高显著提高(P<0.05);乙酸与丙酸的比值随着精粗比的提高逐渐下降。由此可知,本试验条件下,高精料饲粮对南江黄羊体外发酵有显著的影响,随着精料比例的升高,微生物蛋白合成量增加,瘤胃发酵的能量利用效率提高。

This experiment was conducted to study the effects of different forage to concentrate ratios on rumen fermentation in Nanjiang brown goats in vitro. The rumen fluid was collected from three healthy Nanjiang brown goats [average body weight was （25.48？1.48） kg] fitted with permanent rumen fistulas. A single factor experiment design was adopted, and fermentation substrates with different forage to concentrate ratios were allocated to group 10C （90： 10）, group 30C （70： 30）, group 50C （50： 50）, group 70C （30： 70） and group 90C （10： 90）. The results showed that pH was decreased in the culture medium with the increase of dietary forage to concentrate ratio, and group 10C and group 30C were significantly higher than group 70C and group 90C （P〈0.05）. The concentrations of ammonia nitrogen （NH3-N） and total volatile fatty acids （TVFA） were not affected by dietary forage to concentrate ratio. Microbial protein concentration was gradually increased with the increase of dietary forage to concentrate ratio, and group 90C was significantly higher than the other groups （P〈0.05）. Fermentation rate of organic matter （OM） was significantly increased with the increase of dietary forage to concentrate ratio （P〈0.05）. The acetate/propionate was gradually dropped with the increase of dietary forage to concentrate ratio. In conclusion, under the experimental conditions, high concentrate diet has a positive effect on rumen fermentation in Nanjiang brown goats in vitro. With the increase of the concentrate level, microbial protein content and energy efficiency are increased.