添加不同组合支链氨基酸对绵羊整体消化代谢及瘤胃微生物多样性的影响

发布时间：2018-01-30 03:59

本文关键词： 绵羊瘤胃支链氨基酸组合效应消化代谢微生物多样性　出处：《新疆农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：本论文通过3个试验研究了不同支链氨基酸组合对瘤胃发酵参数及微生物种群区系的影响。明确了在不同精粗饲料比条件下BCAA(Val、Leu和Ile)的最佳适宜添加比例与组合效应,阐明了BCAA对结构性碳水化合物在绵羊瘤胃消化代谢和整体消化的影响;揭示BCAA组合对瘤胃微生物多样性和纤维降解菌生长的影响。试验一:本试验利用体外发酵培养技术和正交试验设计,在饲料精粗比20:80、40:60和60:40的饲喂条件下,研究额外添加BCAA的16种组合对绵羊瘤胃微生物体外发酵的影响。结果表明:底物精粗饲料比20:80时,异丁酸和戊酸浓度随着Val水平的增加而呈显著升高(P0.05);异戊酸浓度随着Ile添加水平的增加而增大。底物精粗饲料比40:60时,异丁酸浓度随着Val添加水平的增加而升高,戊酸浓度随着Leu、Ile添加水平的升高而有不同程度的升高,当Val添加水平为0.67 mmol/L时,异戊酸浓度最低。底物精粗饲料比60:40时,异丁酸主要受Val的影响,随着Val水平的增加异丁酸浓度显著增加;异戊酸浓度受Leu和Ile的影响,戊酸浓度受Val和Ile的影响。3种不同发酵底物中添加BCAA组合对pH、NDF降解和乙酸/丙酸均无显著影响。试验二:在试验一的基础上,饲料精粗比20:80的饲喂水平条件下采用4*4拉丁方试验设计,研究Val、Leu、Ile添加水平0.67、0、0.67 mmol/L(组合1),0.67、1.33、2.00 mmol/L(组合2),0.67、2、1.33 mmol/L(组合3)对绵羊瘤胃发酵各参数及营养物质消化代谢的影响。结果表明:3种组合BCAA的添加对乙酸、丙酸、丁酸、TVFA、pH及其他营养物质差异均不显著(P0.05)。组合2的添加使异丁酸、异戊酸产量最大,显著高于对照组(P0.05),使P保留率、NH3-N浓度在各个采样时间均高于其他组。组合3的添加使NDF、TVFA日均浓度最大,显著高于对照组(P0.05)。试验三:在试验二的基础上,利用PCR-DGGE技术、高通量测序技术分析添加BCAA组合对瘤胃微生物区系的影响,结果表明:添加BCAA组合改变了瘤胃微生物的种类、数量及群落结构的构成,对细菌中Victivallis、Bacteroides、Butyrivibrio,真菌中unclassified Eurotiales sp.的丰度影响差异显著,3种不同组合BCAA的添加均有提高绵羊Succiniclasticum丰度的趋势。当Val、Leu、Ile添加水平为0.67、2.00、1.33 mmol/L时,丁酸弧菌属(Butyrivibrio)的丰度提高了34.88%(P0.05)。综上所述:在饲料精粗比20:80的饲喂水平下,额外添加Val、Leu、Ile的浓度为0.67、2、1.33 mmol/L时,在体外使DM、NDF降解率达到最大;在体内,通过提高丁酸弧菌属、降低食物谷菌属、拟杆菌属的相对丰度改变了瘤胃微生物的多样性。
[Abstract]:Three experiments were conducted to study the effects of different branched amino acid combinations on rumen fermentation parameters and microbial population floras. BCAA(Val was determined under different feed ratios. The optimum proportion and combination effect of Leu and Ile were used to elucidate the effects of BCAA on the metabolism of structural carbohydrates in rumen digestion and overall digestion of sheep. The effects of BCAA combination on rumen microbial diversity and cellulolytic bacteria growth were revealed. Experiment 1: in this experiment, the in vitro fermentation culture technique and orthogonal design were used to determine the feed concentrate / diameter ratio of 20: 80. Under the feeding conditions of 40: 60 and 60: 40, the effects of 16 additional combinations of BCAA on rumen microbial fermentation in vitro in sheep were studied. The results showed that the crude feed ratio of substrate concentrate was 20: 80. The concentrations of isobutyric acid and valeric acid increased significantly with the increase of Val level. The concentration of isovaleric acid increased with the increase of Ile addition level, and the concentration of isobutyric acid increased with the increase of Val addition level, while the concentration of valeric acid increased with Leu at the ratio of 40: 60. When the level of Val was 0.67 mmol/L, the concentration of isovaleric acid was the lowest, and the crude feed ratio of substrate concentrate was 60: 40. Isobutyric acid was mainly affected by Val, and the concentration of isobutyric acid increased significantly with the increase of Val level. The concentration of isovaleric acid was affected by Leu and Ile, and the concentration of valeric acid was affected by Val and Ile. 3 kinds of different fermentative substrates were mixed with BCAA on pH. NDF degradation and acetic acid / propionic acid were not significantly affected. Test 2: on the basis of experiment 1, the Val was studied under the feed level of 20: 80 feed concentrate and feed ratio of 20: 80. Leulein Ile added 0.67 mmol / L (0.67 mmol / L) (combination 1, 0.671.33, 2.00 mmol / L). The effects of 1.33 mmol / L (combination 3) on the parameters of rumen fermentation and nutrient digestion and metabolism in sheep were studied. The results showed that the addition of BCAA to the three combinations had effect on acetic acid, propionic acid and butyrate. The difference of pH and other nutrients was not significant (P 0.05). The yield of isobutyric acid and isovaleric acid was the highest in combination 2, which was significantly higher than that in control group (P 0.05), and the retention rate of P was increased. The concentration of NH3-N in each sampling time was higher than that in other groups, and the daily average concentration of NH3-N was the highest with the addition of combination 3. Test 3: on the basis of experiment 2, the effects of adding BCAA combination on rumen microbial flora were analyzed by PCR-DGGE technique and high throughput sequencing technique. The results showed that the addition of BCAA changed the species, quantity and community structure of rumen microorganisms. The abundance of unclassified Eurotiales sp. was significantly different from that of Butyrivibrio. The Succiniclasticum abundance of sheep was increased with the addition of three different combinations of BCAA, when the addition level of BCAA was 0.67g / 2.00. 1.33 mmol/L. The abundance of Vibrio butyricum (Butyrivibrio) increased 34.88% P0.050.In conclusion, Val was added to the feed at the feed level of 20: 80. When the concentration of Leufen Ile was 0.67 mmol/L, the degradation rate of DM-NDF reached the maximum in vitro. In vivo, the relative abundance of Bacteroides changed the diversity of rumen microorganisms by increasing the genus Vibrio butyrate and reducing the relative abundance of the genus Glutazia.
【学位授予单位】：新疆农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S826.5

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