【作者】 郭旭生；

【导师】 姚爱兴； 李爱华；

【作者基本信息】 宁夏大学 ， 草业科学， 2004， 硕士

【摘要】 本研究采用生化复合处理方法研究了其对农作物秸秆营养价值和瘤胃降解率的影响，并利用体外法（in vitro）研究了不同日粮结构和瘤胃调控剂对日粮中粗纤维体外降解及其体外发酵合成产物的影响，旨在通过秸秆的加工调制、饲料间的配合及瘤胃调控法提高秸秆的营养价值和利用率，并为秸秆类饲料和不同瘤胃调控剂在肉羊日粮中的合理应用及其日粮的配制提供理论依据。 1．生化复合处理提高作物秸秆营养价值方法的研究 运用正交优化混合位级L₁₈（6¹×3⁶）法，在7种因素的作用下对玉米秸、麦秸和稻草秸进行了生化复合处理，经过对秸秆中营养成分的检测，筛选本研究中提高秸秆中粗蛋白和降低NDF和ADF的最佳处理方法，并选4只安装永久性瘤胃瘘的滩寒杂交一代羯羊（体重25±2.0 Kg），用尼龙袋法测定了处理后及未处理秸秆瘤胃48h的DM、NDF和ADF的消失率。结果表明，提高秸秆的最佳措施使得玉米秸秆的粗蛋白由原来的3.65％提高到14.44％，增长率为295.48％，其瘤胃48h的DM、NDF及ADF的消失率显著高于未处理玉米秸（p＜0.05）；降低秸秆中NDF和ADF的最好处理方法使得处理麦秸中NDF和ADF分别比原秸秆降低25.91％和24.38％。 2．组合效应对粗纤维体外降解及日粮体外发酵合成产物影响的研究 选3只体重相近（25±2.0 Kg），体况良好，安装永久性瘤胃瘘的滩寒杂交一代羯羊供采集瘤胃液用。应用体外产气法，研究饲料组合效应对日粮体外发酵培养效果的影响，并以微生物蛋白合成量、产气、NH₃-N、粗纤维的降解率，VFA（乙酸、丙酸、丁酸）等作为评价因素，对15种不同日粮结构及营养结构的育肥羊全混合日粮体外发酵效果进行综合评判以筛选较优的日粮及其适宜的精粗比，结果表明：饲料组合效应对日粮体外发酵培养效果有显著影响（p＜0.05）。且当日粮的精粗比为55：45，其中复合处理玉米秸及苜蓿草粉的替换比例分别为25％和20％时，其体外发酵效果最好。 3．不同瘤胃调控剂对日粮粗纤维体外降解及体外发酵合成产物影响的研究 选3只体重相近（25+2.0 Kg），体况良好，安装永久性瘤胃瘘的滩寒杂交一代羯羊供采集瘤胃液用。应用体外产气法研究了不同瘤胃调控剂对肉羊秸秆型全混合日粮体外发酵的影响，结果表明：以全混合日粮为发酵底物时，细菌-N合成量及日粮中的粗纤维降解率开始随莫能菌素浓度的升高而增加，两者分别与瘤胃素的浓度呈二次幂函数关系，且当瘤胃素的浓度为0.0323mg／ml时，细菌-N的合成量最高；浓度为0.0287mg／ml时，粗纤维的降解率最高；同时，瘤胃素的添加显著提高了日粮体外发酵过程中细菌-N的合成量（p＜0.05）；瘤胃素对体外产气有抑制作用，其浓度与产气量呈负相关，并随其浓度增加乙丙酸比例降低;当发酵底物中添加YC后，培养液中细菌氮的合成量增加，但与对照组相比差异不显著（P>0.05）。YC对发酵底物中的粗纤维发酵24h后的降解率有显著影响（P<0 .05），且培养液中NH，一N的浓度显著高于对赚组（P<0 .05），但对乙丙酸比例影响不显著（P>O.05）。同时，本试验表明瘤胃素、Yc和稀土对日粮体外发酵效果有明显的互作效应（P<0.05）。更多还原

【Abstract】 The biochemical processing methods were applied in the first experiment to improve nutrient value of crop fodder and its degradation rate in situiand based on in viro, other experiments were conducted to study the effects of various concentration/roughage of mutton sheep total mixed ration and rumen manipulation doses on crude fiber degradation and fermenting synthesized production of the tested rations.1. Study on biochemical treatment methods to improve nutrient value of crop fodderThe Orthogonal Experiment Design [L18 (61X3) ] of seven factors was applied in this experiment and through biochemical treatment methods the maize stover, wheat straw and rice straw were processed, then by nutrient ingredients detection of the treated fodder to screen the optimum method of improving their nutrient value in this test. Meanwhile, the in situ degradation rate of the treated and untreated fodder were determined with 4 Tan-Han crossbreed castrated sheep fitted with permanent cannulas in the rumen. The results show that the crude protein percentage content of maize stover be improved from 3.65% to 14.44%, and its DM.NDF, ADF in situ degradation rate is higher than untreated maize stover(p<0.05) ;the NDF and ADF percentage content of treated wheat straw decreased by 25.91% and 24.38% respectively compared with untreated wheat straw by using optimum methods in this study.2. Associative effects of different feeds on in vitro crude fiber degradation and fermentation effects of various fattening lamb total mixed rationsThree Tan-Han crossbreed castrated lamb fitted with permanent cannulas were used as donated animals for collecting rumen fluid. Applying the method of in vitro gas production and comprehensive judgment of multiple factors, with the multiple factors of gas production, microorganism protein production, degradation rate of crude fiber, VFA production and concentration of NHa-N, to evaluate the fermentation effects of 15 kinds of various feed and nutrient compose of fattening lamb total mixed rations. The results show that the associative effects of ration on its in vitro fermentation results is significantly(p<0.05),and the comprehensive fermentation character of the ration, which roughage and concentration rate is 45:55and the biochemical treatment corn straw and alfalfa powder substitute rate in ration are 35% and 20% respectively, is the best. 3. Different rumen manipulation doses on in vitro crude fiber degradation and the fermentation effect of various fattening lamb total mixed rationsThree Tan-Han crossbreed castrated lamb fitted with permanent cannulas were used as donated animals for collecting rumen fluid. Based on in vitro, the experiment was conducted to study on the effects of different rumen manipulation doses on the fermentation effect of various fating lamb total mixed ration . The results showed that when the tested ration added monesin and fermented in vitro, the yield of bacterial-N and the crude fiber(CF) degradation were increased with the increase of monesin concentration at first and reached maximum value as the monesin concentration were 0.0287mg/ml and 0.0323mg/ml respectively;The effect of monesin concentration on the yield of bacterial-N was significantly(p<0.05);The gas production was restrained after monesin was added in the tested ration; The acetone yield was decreased with the increase of monesin concentration ; The yield of bacterial-N in fermenting solution was increased when YC was added in the ration but the difference was not significant compared with the control group(p>0.05);However, YC effect the crude fiber degradation significantly after fermenting 24h in vitro(p<0. 05), and the concentration of NHrN was higher than control group(p<0.05),but on the acetic acid/acetone , the YC effect was not significantly(p>0.05). Meanwhile, the experiment results showed that monesin, YC and rare earth have distinct interaction on the fermentation results of test ration.更多还原