体外产气法研究椰子油对瘤胃发酵、菌群数量及酶活性的影响

试验旨在研究椰子油(CCO)对瘤胃发酵、菌群数量及酶活性的影响,各组CCO添加量为日粮干物质的0%(对照组)、1%、3%、5%、7%和9%,体外发酵48 h。结果表明:5%、7%和9%添加组pH高于其余各组(P<0.05),总挥发性脂肪酸(TVFA)浓度低于其余各组(P<0.05);与对照组、1%和3%添加组相比,7%和9%添加组乙酸摩尔百分比和乙酸/丙酸降低(P<0.05),丙酸摩尔百分比增加(P<0.05);添加CCO降低了甲烷产量和原虫数量(P<0.05);7%和9%添加组羧甲基纤维素酶活性低于其余各组(P<0.05);5%、7%和9%添加组纤维二糖酶、木聚糖酶和蛋白酶活性低于对照组和1%添加组(P<0.05),细菌总数、白色瘤胃球菌、黄色瘤胃球菌、产琥珀酸丝状杆菌、嗜淀粉瘤胃杆菌和栖瘤胃普雷沃氏菌数量低于其余各组(P<0.05)。综上可知,TVFA浓度、微生物数量及酶活力随CCO的添加量增加而降低;CCO的最大添加量不宜超过日粮干物质的3%。

Effects of Coconut Oil Supplementation on Rumen Fermentation,Bacteria Abundance and Enzyme Activity in vitro

The objective of the study was to evaluate the effects of coconut oil(CCO) supplementation on ruminal fermentation, bacteria abundance and enzyme activity in vitro. Coconut oil was supplemented at the rate of 0%, 1%, 3%, 5%,7% and 9% of dietary dry matter and fermented for 48 h. Ruminal pH was higher(P<0.05) and total volatile fatty acids(VFA)was lower(P<0.05) in 5%, 7% and 9% groups than in control, 1% and 3% groups. Molar proportion of acetate and acetate to propionate ratio were lower(P<0.05), and propionate molar proportion was higher(P<0.05) in 7% and 9% groups than in control, 1% and 3% groups. Methane production and protozoa abundance decreased(P<0.05) by CCO supplementation.Activity of carboxymethyl cellulose was lower(P<0.05) in 7% and 9% groups compared with other groups. Activities of cellobiase, xylanase and protease were lower(P<0.05) in 5%, 7% and 9% groups than in control and 1% groups. Abundance of total bacteria, R. albus, R. flavefaciens, F. succinogenes, B. fibrisolvens and P. ruminicola were lower(P<0.05) in 5%, 7% and 9% groups than in other groups. The data indicated that ruminal total VFA concentration, bacteria abundance and enzyme activity decreased with increasing CCO supplementation, and the largest supplementary dose of CCO was not more than 3%of dietary dry matter.