| 摘要: |
| 【目的】研究3种不同氮源日粮中添加烟酸对绵羊瘤胃发酵的影响，为生产实践提供理论依据。【方法】将9只装有永久性瘤胃瘘管的绵羊随机分为3组，每组3只，分别饲喂豆粕、麻饼和尿素 麻饼型基础日粮。通过体外培养法研究添加一定量烟酸后，3种不同氮源日粮在培养0,0.5,1,2,4,8,12,16,20,22 h后，培养液中NH3-N和细菌N质量浓度、原虫数、总挥发性脂肪酸(VFA)及乙酸、丙酸浓度和乙酸/丙酸的变化情况。【结果】添加烟酸后，尿素 麻饼型日粮培养液中NH3-N和细菌N质量浓度和原虫数均高于豆粕型日粮，而豆粕型日粮又高于麻饼型日粮，差异显著性随培养时间而变化；尿素 麻饼型日粮NH3-N质量浓度在培养2 h达最高，之后下降，在4 h后趋于平稳，而细菌N质量浓度在培养0～12 h有升高趋势，12～22 h又降低，但差异均不显著（P＞0.05）。豆粕型日粮在培养2 h内NH3-N质量浓度升高，之后下降，在培养4 h达最低，4 h后又缓慢升高；而细菌N质量浓度在0～8 h升高，8～22 h下降。麻饼型日粮在培养过程中，NH3-N和细菌N质量浓度差异均不显著（P＞0.05）。3种日粮培养液中原虫数均在培养后4 h达最高值，之后有所下降。不同氮源日粮对总挥发性脂肪酸、乙酸、丙酸浓度及乙酸/丙酸的影响差异均不显著（P＞0.05）。【结论】添加烟酸后，尿素 麻饼型日粮NH3-N利用率较高，产生较多的细菌和原虫，饲喂效果优于其他2种日粮；麻饼型日粮饲喂效果最差。 |
| 关键词: 体外培养法 绵羊 烟酸 瘤胃 日粮氮源 |
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| 基金项目:安徽省自然科学基金项目（090411019） |
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| Study on ruminal fermentation of the sheep in three nitrogen diets supplied niacin in vitro |
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| Abstract: |
| 【Objective】The research was done to study rumen fermentation in three different nitrogen source diets added niacin in vitro to provide a theoretical basis for the practice.【Method】The rumen fluid derived from 9 sheep installed permanent rumen fistula in the experiment were randomly divided into 3 groups,3 sheep/group,and were fed soybean meal,linseed meal and urea linseed meal type basic diet,respectively.Then the concentration of NH3-N,bacterial N concentration,protozoa,total volatile fatty acids (VFA) and acetic acid, propionic acid and acetic acid/propionic acid value were studied in the culture medium of the three nitrogen sources after culturing 0,0.5,1,2,4,8,12,16,20,22 h in vitro when these diets were added niacin.【Result】After adding nicotinic acid,concentration of NH3-N,bacteria N concentration and protozoan numbers in the culture medium of urea linseed meal diet were higher than those in soybean meal diet,while the soybean meal diet was higher than linseed meal based diets,significant difference changed with culture time.The NH3-N concentration increased to a maximum at 2 h after the culture then decreased,stabiled after 4 h in the medium urea linseed meal diet;The bacterial N concentration increased 0-12 h after culturing,12-22 h decreased,but no significant difference existed(P>0.05).The NH3-N concentration increased 2 h after culturing,decreased to a minimum at 4 h after culturing,then slowly increased;The bacterial N concentration increased in 0-8 h,decreased in 8-22 h in the medium of soybean meal diet.The concentration of NH3-N,bacterial N concentration were not significantly different in the whole culturing process of linseed meal based diet (P>0.05).The protozoa numbers in the three kinds of diets reached the maximum in 4 h,respectively,then decreased.The total volatile fatty acids (VFA),acetic acid,propionic acid and acetate/propionate didn’t show significant difference in different cultures (P>0.05).【Conclusion】After adding nicotinic acid,the utilization of NH3-N was the highest in the medium of urea linseed meal diet,produced more bacteria and protozoa,hence the urea linseed meal diet was better than the soybean meal diet,and linseed meal based diet was the worst. |
| Key words: in vitro sheep niacin rumen nitrogen diet |
