【作者】 丁健；

【导师】 赵国琦； 王志跃；

【作者基本信息】 扬州大学 ， 动物营养与饲料科学， 2003， 硕士

【摘要】 本试验以安装永久性瘤胃瘘管的徐淮白山羊为试验动物，研究了10：0、8：2、6：4和4：6四种粗精比日粮条件下瘤胃内环境参数的昼夜动态变化规律及瘤胃混合细菌、纤毛虫体组成成分；利用体外发酵试验研究了4种粗精比日粮对瘤胃细菌产量及(¹⁵NH4)₂SO₄利用效率的影响；从山羊瘤胃中分离培养出6株无机氮利用细菌，对其部分生理特性进行了研究，并对细菌进行了生化鉴定。研究结果表明： 1．瘤胃pH值随日粮粗精比的降低而降低。pH平均值由10：0组的6.37降至4：6组的5.86，其中10：0组极显著高于8：2、6：4和4：6组（P＜0.01），8：2、6：4和4：6组组间差异不显著（P＞0.05）。 2．瘤胃氨态氮平均浓度随日粮粗精比的降低而升高。氨氮浓度的平均值分别由10：0组的8.37mg·100ml^-1，升至4：6组的13.71mg·100ml^-1，其中10：0组极显著低于8：2、6：4和4：6组（P＜0.01），8：2、6：4和4：6组组间差异不显著（P＞0.05）。 3．发酵参数昼夜波动趋势显示：瘤胃pH值均在采食后下降，1～3小时下降至最低后又开始上升；氨态氮浓度在采食后升高，1～2小时至最高点，后开始下降。 4．瘤胃乙酸浓度以8：2组最高，为46.23mmolL^-1，极显著高于10：0、6：4和4：6组（P＜0.01），10：0、6：4、4：6三组则依次降低，但组间差异不显著（P＞0.05）；丙酸浓度以8：2、4：6两组较高，分别为15.09、15.75mmolL^-1，极显著高于10：0和6：4组（P＜0.01），8：2与4：6以及10：0与6：4组组间差异不显著（P＞0.05）；丁酸浓度随粗精比降低而升高，4：6组最高，为9.02mmolL^-1，极显著高于6：4和8：2组（P＜0.01），6：4和8：2组间差异不显著（P＞0.05），极显著高于10：0组（P＜0.01）。总VFA浓度则以8：2组最高，为68.48mmolL^-1，极显著高于4：6组（P＜0.01），4：6组又显著高于10：0、6：4组（P＜0.05），10：0与6：4组间差异不显著；乙酸/丙酸比值随着粗精比的降低而减小，10：0组最大，为3.85，极显著大于8：2、6：4和4：6组（P＜0.01），8：2、6：4和4：6各组间差异不显著（P＞0.05）。 5旧粮粗精比对细菌总氮含量产生影响。6:4组显著高于8:2组，极显著高于4:6 组，与10:O差异不显著;粗精比对细菌脂肪含量影响差异不显著，对纤毛虫总 氮及脂肪含量也均无显著影响（P>O.05）。 6.细菌体17种氨基酸中有4种氨基酸的相对百分组成受日粮粗精比的影响，它们 分别为:赖氨酸、胧氨酸、谷氨酸和组氨酸;纤毛虫体中氨基酸的相对百分组 成较稳定，仅撷氨酸受日粮粗精比的影响。 7.体外培养体系中，pH值与氨氮浓度均在培养前8小内急剧下降，之后下降趋势 趋于平缓。24小时培养的细菌产量在8:2、6:4和4:6组中差异不显著，但极显，著高于10:0组，10:0组与空白组差异不显著;菌体’SN原子丰度以8:2及4:6组 较高，显著高于10:0组（P<0.05），极显著高于空白组（P<0.01）:菌体‘’N富集 量以8:2组最高，底物中547.43 09，SN中，有120.44 09被细菌富集，显著高于 10:0组（P<0.05），6:4、4:6与10:0组间差异均不显著（p>0.05）。 8.分离培养瘤胃细菌共得到6株对尿素、N场CI、困H4)250;和困H4)ZCo3有不同利 用能力的无机氮素利用菌。其中2株为G十球菌、其余为G一杆菌;6株细菌中有 5株为需氧兼性厌氧菌:分离出的细菌pH耐受范围较宽，为4.5一10.0;对高温 较敏感，能耐受温度为45℃，50℃不生长;小白鼠毒性试验表明，大剂量口服 菌液小鼠均无不良反应;细菌初步鉴定结果:一株为纤维单胞菌属、一株为放 线杆菌属、一株为拟杆菌属，其余三个菌株的种属还有待进一步研究确定。更多还原

【Abstract】 Three xuhuai white goats fitted with permanently ruminal cannlas were used in a 4x3 latin square design to evaluate the effects of roughage to concentrate ratio(R:C ratio) diet on dynamic changing rules of ruminal internal environment parameters and bacteria and protozoa composition. 4 different diets varied in R:C ratios among 10:0, 8:2, 6:4 and 4:6; The study also determined the effect of 4 diets on l5N-ammonium sulfate utilization by mixed ruminal bacteria in vitro; 6 kinds of bacteria were isolated and pure cultured from rumen contents of goats, the ability of inorganic nitrogen utilization and physiological characteristics were also identified. The results showed that: 1.Decreased R:C ratio decreased ruminal pH. pH decreased from 6.37 to 5.86 if R:C ratio varied from 10:0 to 4:6. pH in 10:0 group was much higher than that in 8:2, 6:4 and 4:6 groups (p<0.01), no clear differences were detected among 8:2, 6:4 and 4:6 groups (P>005).2.Lower R:C ratio increased ammonia-N(NH3-N) concentration. NH3-N concentration increased from 8.37 to 13.71 mg·l00ml-1 if R:C ratio decreased from 10:0 to 4:6. 8:2, 6:4 and 4:6 groups increased NHs3N concentration to a large extent compared with 10:0 group (P<0.01).3.Ruminal pH decreased to the lowest point after eating 1~3 hours, then increased until the next time’ s eating. Similarly, NH3-N concentration increased to the highest point after eating 1 ~2 hours, then decreased until the next time’ s eating. 4.The highest acetic acid concentration was observed in 8:2 group, much higher than in 10:0, 6:4 and 4:6 groups (P<0.01). Acetic acid concentration decreased orderly in 10:0, 6:4 and 4:6 groups; On the other hand, butyric acid concentration increased orderly in 10:0, 8:2, 6:4 and 4:6 groups; Propionic acid concentration were 15.09,15.75mmolL-1 respectively in 8:2 and 4:6 groups, much higher than that in 10:0 and 6:4 groups (P<0.01). The highest level of total volatile fatty acids(TVFA) was observed in 8:2 group (68.48mmol/L), much higher than that in other three groups. Acetate/propionate(C2/C3) ratio decreased orderly when R:C ratio decreased from 10:0 to 4:6. Except 10:0 group, there were no clear differences among 8:2, 6:4 and 4:6 groups.6.Various R:C ratio diets showed different influences on total nitrogen(TN) content of bacteria, while diets had negligible effects on TN content of protozoa and fat content of bacteria and protozoa.7.Comparison of bacteria amino acid(AA) from different groups indicated differences for 4 out of 17 AA measured, they were lysine(Lys), cystine(Cys), glutamic acid(Glu) and histidine(His) respectively. Protozoa were found to be different for 1 out of 17 AA measured, it was valine(Val).8.In vitro, pH and NH3-N concentration rapidly decreased in first 8 hours’ incubation, then the speed of decrease became slow in later incubation times. At the end-point of the incubation (24 hours), bacteria isolated from 8:2, 6:4 and 4:6 groups had much higher biomass compared with 10:0 and blank groups, and the same trend was observed in the 15N-enrichment of bacteria. There was 547.43 μ g 15N in medium solution, and the amount of l5N-incorporation into bacteria at the incubation end-point was 120.44 μ g.9. 6 kinds of bacteria from rumen contents of goats were obtained. In physiological-biochemical characteristics test, the tested bacteria had different abilities of inorganic nitrogen utilization; 2 out of 6 kinds of bacteria were G+ coccus, others were G- bacillus; 5 out of 6 kinds of bacteria were facultative anaerobic bacteria; All of bacteria were tolerant to pH4.5-10.0 and the highest temperature 45 ; The behavior and reaction of mice were normal, had no toxicity symptom after mice were given bacteria liquids of high dose by oral administration; The preliminary identify result of 6 kinds bacteria was that: one for Cellulomonas flavogensis, one for Actinobacillussuis, one for bacteroides, three other kinds of bacteria species were not confirmed yet.更多还原