【作者】 齐智利；

【导师】 嘎尔迪；

【作者基本信息】 内蒙古农业大学 ， 动物营养与饲料科学， 2004， 博士

【摘要】 以体外（in vitro）、半体内（in situ）和体内（in vivo）方法相结合的技术手段研究了不同加工处理的玉米对奶牛瘤胃发酵、小肠消化、以及能氮同步代谢和生产性能的影响，旨在为瘤胃发酵调控和反刍动物营养物质的有效利用以及日粮的合理配制提供科学的理论依据。第一部分 In sacco法评定加工处理玉米和常用饲料原料在泌乳奶牛瘤胃内营养物质动态降解规律的研究以3头年龄、体重、日平均产奶量相近，体况良好，安装有永久性瘤胃瘘管的泌乳前期奶牛为试验动物，在日粮精粗比为55：45的前提条件下，应用in sacco法（瘤胃尼龙袋法）研究了几种不同加工处理的玉米（膨化、烘烤、制粒、压扁、焙炒处理玉米）和奶牛常用饲料（玉米、麸皮、豆粕、胡麻饼、棉粕、青干草以及玉米青贮）的淀粉、有机物和蛋白质的瘤胃降解规律，结果表明：不同加工处理方式均不同程度的影响玉米瘤胃淀粉、有机物和蛋白质的降解规律。挤压膨化和制粒以及压扁加工处理能显著的提高玉米在瘤胃中的淀粉降解率（P<0.05），而烘烤与焙炒加工处理能显著的降低玉米在瘤胃中的淀粉降解率（P<0.05）。淀粉瘤胃降解率由高到低顺序依次为膨化玉米>帕Ｓ衩?贡庥衩?未处理玉米>焙炒玉米 >1400C 35min烘烤玉米。其中膨化处理中，随着挤压膨化温度的升高，淀粉瘤胃降解率呈线性下降，降解率由高到低顺序依次为1300C膨化玉米，1400C膨化玉米和1500C膨化玉米。膨化温度与淀粉瘤胃降解率呈高度线性相关，其回归方程为Y=-0.211X+106.26（R2=0.9876，N=3）；烘烤处理中，玉米经过不同温度和时间的烘烤处理，淀粉的瘤胃降解率都有不同程度的降低，随着温度逐渐升高和作用时间的逐渐延长，淀粉的瘤胃降解率也逐渐降低，1400C 35min烘烤玉米的瘤胃淀粉降解率最低。淀粉在瘤胃中降解的影响因素最主要的是淀粉的快速可溶部分S和慢速降解部分D的降解速率Kd。泌乳奶牛常用饲料中淀粉、有机物和蛋白质的瘤胃降解规律有所不同，能量饲料中，麸皮的淀粉和蛋白质瘤胃降解率都高于未处理玉米，有机物的降解率二者没有明显区别；蛋白质饲料中，豆粕的淀粉、有机物和蛋白质的降解率均高于胡麻饼和棉粕，胡麻饼的淀粉和有机物的降解率高于棉粕，但是蛋白质的降解率低于棉粕；常用粗料中，青贮的淀粉和有机物以及蛋白质的降解率均高于干草。第二部分 牛小肠液冻干粉（BIF）法评定不同加工处理的玉米对小肠消化率的影响以牛小肠液冻干粉（BIF）法来研究不同加工处理玉米瘤胃12h非降解残渣在小<WP=3>肠中的消化率，首先筛选出用BIF法评定淀粉在奶牛小肠消化率的适宜培养条件，然后利用筛选出的最佳培养条件测定了各种处理玉米12h瘤胃非降解残渣的小肠消化率，结果表明：牛小肠液冻干粉（BIF）法研究12h过瘤胃玉米淀粉的小肠消化率的最适宜培养条件为：0.5gBIF/0.5g饲料，McDougall缓冲液，pH值为7.0，Ca2+为680uM，温度为39℃，最佳培养时间为8h。加工处理对玉米小肠淀粉消化率的影响不同，膨化加工可以明显提高过瘤胃淀粉的小肠消化率，烘烤、制粒、压扁以及焙炒加工处理对过瘤胃淀粉的小肠消化率没有明显影响。结合第一部分试验结果得出，在本试验条件下，不同温度膨化处理组中，130℃膨化处理的效果较好。不同温度和时间的烘烤处理组中，1300C 35min烘烤加工是较好的处理方式。第三部分 不同过瘤胃淀粉日粮对泌乳奶牛瘤胃发酵、营养物质利用和产奶性能以及血液指标的影响以3头年龄、体重、日平均产奶量相近、体况良好，安装有永久性瘤胃瘘管的泌乳前期奶牛为试验动物，在日粮精粗比为55：45的前提条件下，采用3×3完全拉丁方试验设计，研究了仅在玉米加工处理方法上不同的三种日粮，即膨化处理组日粮（低过瘤胃淀粉日粮）、焙炒处理组日粮（高过瘤胃淀粉日粮）和对照组日粮（含未处理玉米的日粮）对泌乳奶牛瘤胃发酵、营养物质利用、产奶性能和相关血液指标的影响。研究结果表明：膨化组和焙炒组与对照组相比，对瘤胃内环境发酵指标没有明显影响（P>0.05），但膨化处理有使瘤胃总VFA浓度增加、pH值降低、氨氮浓度下降、瘤胃原虫数量增加、细菌蛋白浓度下降、液相菌体蛋白库容量有所减少的趋势；而焙炒处理使瘤胃总VFA浓度降低、氨氮浓度下降、瘤胃原虫数量下降、细菌蛋白浓度升高、瘤胃液相流通速率略有降低、液相菌体蛋白库容量有一定程度的增加的趋势。与膨化组比，焙炒组的总VFA浓度明显降低（P<0.05）。三组不同日粮对营养物质的采食、排泄以及消化利用有着一定的规律性。与其它两组相比，膨化处理组（低过瘤胃淀粉含量组）的DM、OM、NDF和ADF的采食量均有所增加，CP采食量却低于其它两组。粪中营养物质的排出量略高于其它两组，其中粪NDF排出量明显高于其它两组。对DM、OM、NDF和ADF的消化率略低于对照组，略高于焙炒组，而CP的消化率均低于其它两组。与对照组比，焙炒组（高过瘤胃淀粉含量组）DM、OM、NDF和ADF的采食量有所减少，但CP采食量和粪中营养物质的排出量却高于对照组。DM、OM、CP、NDF和ADF的消化率略有降低。膨化处理使N采食量相对减少，粪N排出量相对增加，尿N排出量、尿中尿素N和尿素N/尿N均相对减少，沉积N与对照组相当?更多还原

【Abstract】 Combined with In Vitro, In Sacco, and In Vivo techniques, this paper studies the effects of processed corns on ruminal fermentation, intestinal digestion, the synchronous metabolism of energy and nitrogen, and production performance of lactating cows, in order to provide the theoretical base for ruminal fermentation manipulation, ration formulation and the effective utilization of nutrients by ruminants. 4 parts are included as follows:Part 1. Study on the dynamic degradation regularity of processed corns and common-used feedstuffs in the rumen3 health Chinese Holstein lactating cows with permanent ruminal cannulas were selected as experimental animals. Cows were fed at the ratio of concentration to roughage 55:45, to investigate the starch, OM and CP degradabilities of processed corns (expanding, toasting, pelleting, rolling and roasting) and common-used feedstuffs (corn, wheat bran, soybean meal, flaxseed meal, cottonseed meal, hay and corn silage). The result shows that the ruminal degradabilities of starch, OM and CP are affected by different processing methods. Expanding and pelleting methods significantly increase the starch degradability（P<0.05）, while that of toasting and roasting apparently decrease the starch degradability（P<0.05）. The sequence of starch degradability is expanded corn>elleted corn>rolled corn>control corn>roasted corn>toasted corn(140℃,35min). As for the expanded corn, the starch degradability decreases linearly as the temperature rises from 130℃ and 140℃ to 150℃; There’s a linear relationship between expanding temperature and starch degradability; the regression equation is Y=-0.211X+106.26 (r2=0.9876,N=3). Treated by different temperature and time, the ruminal starch degradability decreases to some degree by toasting processing. As the temperature rises and time prolongs, the starch degradability decreases gradually. The lowest degradability is found under the condition of 140℃,35min. The major factors affecting ruminal starch degradability may include the rapidly degraded fractions (S) and the degradation rate (Kd) of slowly degraded fractions (D). The result also shows that the ruminal degradation regularity of starch, DM and CP of common-used feedstuffs are different. As to energy feedstuffs, wheat bran has higher starch and CP degradabilities than that of control corn, while OM degradability is <WP=6>insignificant between them. As for protein feedstuffs, starch, OM and CP degradabilities of soybean meal are higher than that of flaxseed meal and cottonseed meal; starch and OM degradabilities of flaxseed meal are higher than that of cottonseed meal, but protein degradability is lower than that of cottonseed meal. As to the roughage, starch, OM, CP degradabilities are higher than that of hay.Part 2. Determination of the effects of processed corns on intestinal digestibility by BIF technique.The intestinal digestibility of ruminal non-degradable residues of processed corns (after 12h culture) was studied by BIF technique. The result shows that the best culture condition is as follows: 0.5g BIF/0.5g feed, McDougall buffer, pH 7.0, Ca2+ concentration 680um, 39℃and 8h. Processing methods affect the intestinal digestibility to some degree. Expanding significantly increases the intestinal digestibility（P<0.05）, but toasting, pelleting rolling and roasting have no significant effect compared with control corn（P>0.05）. Combined with the result in Part 1, 130℃ expanding and 140℃,35min toasting are relatively better processing methods in this experiment.Part 3. The effects of different bypass starch diets on ruminal fermentation, nutrients utilization, lactation performance and blood indices in lactating cows.3 above-mentioned lactating cows were selected as experimental animals with the ratio of concentrate to roughage 55:45. A 3×3 Latin Square design was used to study the effects of 3 diets (expanded, roasted and control corn diets) on ruminal fermentation, nutrients utilization, lactation performance and blood indices in lactating cows. Expanded and ro更多还原