乙酰氧肟酸的合成及其对奶牛瘤胃尿素氮代谢和微生物的影响

发布时间：2018-01-10 21:37

本文关键词：乙酰氧肟酸的合成及其对奶牛瘤胃尿素氮代谢和微生物的影响　出处：《中国农业科学院》2017年博士后论文　论文类型：学位论文

【摘要】：脲酶抑制剂可以抑制奶牛瘤胃脲酶活性,减缓尿素在瘤胃内的分解速度,提高尿素氮利用效率。本实验旨在优化脲酶抑制剂乙酰氧肟酸的合成工艺,并借助奶牛饲养实验,验证产品乙酰氧肟酸对奶牛瘤胃尿素氮代谢的影响;借助体外发酵实验,验证产品乙酰氧肟酸对奶牛瘤胃微生物的影响。结果表明,乙酰氧肟酸的合成工艺得到优化,产品产出率为84.6%,纯度为97%。产品乙酰氧肟酸显著抑制奶牛瘤胃氨氮和尿素氮浓度(P0.01),显著提高奶牛尿液中嘌呤衍生物的浓度(P = 0.01),对奶牛血氨浓度和瘤胃pH值均无显著影响,对奶牛瘤胃液挥发性脂肪酸、血液常规指标、产奶量和乳脂肪、乳蛋白均无显著影响。添加产品乙酰氧肟酸和尿素显著提高了微生物群落的香浓-威纳指数(P0.05),尿素显著降低了瘤胃内Ruminococcus albus,Ruminococcus flavefaciens,Fibrobacter succinogenes 和 Butyrivibrio fibrosolvens 菌的丰度(P0.01),而产品乙酰氧肟酸在发酵前期缓和了由添加尿素引起的上述纤维分解菌丰度的降低(P0.05)。此外,添加尿素显著提高了(P0.01)Pseudomonas,Streptococcus,Haemophilus,Neisseria 和 Actinomyces 菌属的丰度,而补充产品乙酰氧肟酸后显著降低了上述菌属的丰度。综上,脲酶抑制剂乙酰氧肟酸的合成得到优化;产品乙酰氧肟酸有利于奶牛瘤胃尿素氮代谢;产品乙酰氧肟酸引起了短期内瘤胃细菌多样性水平的升高,缓解了由于氨的瞬时累积引起的瘤胃纤维分解菌生长受阻的现象,且奶牛瘤胃内丰度较高的尿素分解菌主要分布于Pseudomonas,Streptococcus,Haemophilus,Neisseria 和 Actinomyces菌属中。
[Abstract]:Urease inhibitor can inhibit the activity of rumen urease, slow down the rate of urea decomposition in rumen, and improve the utilization efficiency of urea nitrogen. The purpose of this experiment was to optimize the synthesis process of urease inhibitor acetyl hydroxamic acid. The effect of acetyl hydroxamic acid on urea nitrogen metabolism in the rumen of dairy cattle was verified by dairy cattle feeding experiment. The effect of acetyl hydroxamic acid on rumen microorganism of dairy cattle was verified by in vitro fermentation. The results showed that the synthetic process of acetyl hydroxamic acid was optimized and the yield of the product was 84.6%. The purity of the product was 97%. Acetyl hydroxamic acid significantly inhibited the concentration of ammonia nitrogen and urea nitrogen in the rumen of dairy cows (P 0.01), and significantly increased the concentration of purine derivatives in the urine of cows (P = 0.01). There was no significant effect on blood ammonia concentration and rumen pH, but on volatile fatty acids in rumen fluid, blood routine indexes, milk yield and milk fat. The addition of acetyl hydroxamic acid and urea significantly increased the aroma-Weiner index (P0.05) of microbial community. Urea significantly decreased Ruminococcus albusococcus flavefaciens in rumen. The abundance of Fibrobacter succinogenes and Butyrivibrio fibrosolvens was P0.01). The product acetyl hydroxamic acid alleviated the decrease of the cellulolytic bacteria abundance caused by the addition of urea in the early stage of fermentation. The addition of urea significantly increased P0. 01 Pseudomonas sp. Streptococcus sp. Haemophilus. The abundance of the genus Neisseria and Actinomyces decreased significantly after the addition of acetyl hydroxamic acid. The synthesis of urease inhibitor acetyl hydroxamic acid was optimized. Acetyl hydroxamic acid was beneficial to urea nitrogen metabolism in the rumen of dairy cattle. Acetohydroxamic acid caused the increase of rumen bacterial diversity in a short period of time and alleviated the phenomenon that the growth of rumen fibrinolytic bacteria was blocked due to the instantaneous accumulation of ammonia. The Urea decomposing bacteria with high rumen abundance were mainly distributed in Pseudomonas sp. Streptococcus sp. Haemophilus. In the genus Neisseria and Actinomyces.
【学位授予单位】：中国农业科学院
【学位级别】：博士后
【学位授予年份】：2017
【分类号】：S823.5

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