| 摘要: |
| 采用体外产气量法,研究了在高水平玉米秸(70%)底物日粮中添加烟酸(0、3和9μg/mL)对瘤胃发酵和纤维降解的影响。结果显示:日粮添加烟酸显著提高了72 h产气量、48 h总挥发酸的浓度、发酵液的羧甲基纤维素酶和木聚糖酶的活性以及72 h干物质、中性洗涤纤维的降解率(P<0.05),而对发酵液的潜在产气量、产气速度、pH、氨态氮浓度、各挥发酸摩尔比、原虫和细菌的数量以及微晶纤维素酶活、酸性洗涤纤维的降解率无显著影响(P>0.05)。随烟酸添加水平的增加,原虫的数量(P=0.082)、潜在产气量(P=0.056)、微晶纤维素酶活(P=0.078)和酸性洗涤纤维的降解率(P=0.093)均呈上升的趋势。添加烟酸3和9μg/mL组的乙酸生成量分别提高5.33%、7.57%,丙酸生成量分别提高5.61%、7.74%,干物质降解率分别提高3.34%、3.37%,中性洗涤纤维降解率分别提高2.69%、2.76%,酸性洗涤纤维降解率分别提高了2.33%、2.41%。体外试验表明:在高水平玉米秸(70%)底物日粮中添加烟酸促进了纤维降解。 |
| 关键词: 烟酸,瘤胃发酵,纤维降解 |
| DOI：10.11841/j.issn.1007-4333.2006.05.122 |
| 投稿时间：2006-04-24 |
| 基金项目:国家自然科学基金 |
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| Effects of niacin on rumen fermentation and fibre degradation in vitro |
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| Abstract: |
| An in vitro study was conducted to study the effects of niacin addition to the dietary substrates on rumen fermentation and fibre degradation.The addition of niacin significantly increased total gas production,TVFA concentration,the activity of CMCase and Xylanase,and the degradation of DM and NDF(P<0.05),while did not significantly effect on the total counts of protozoa and bacteria,the potential gas production,the rate of gas production,pH,the ammonia-N concentration,the molar percentage of VFA,the ratio of acetate to propionate,the activity of Avicelase,and the degradation of ADF(P>0.05).The total counts of protozoa(P=0.082),the potential gas production(P=0.056),the activity of Avicelase(P=0.078),and the degradation of ADF(P=0.093) had an increasing tendency with the increase of niacin level.The current study suggested that the addition of niacin had beneficial effects on fibre degradation when the diet(fermentation substrate) contained higher corn stalk(70%). |
| Key words: niacin,rumen fermentation,fibre degradation |
