【作者】 卢寿锋；

【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， 硕士

【摘要】 本论文结合体内法、半体内法和体外法，就不同加工处理的玉米对泌乳奶牛瘤胃能氮同步代谢及小肠消化的影响进行了研究。论文包括以下5个试验：试验一 对玉米进行物理加工处理（膨化、制粒、压扁、烘炒和对照），并测定各饲料原料（玉米、麸皮、豆粕、胡麻饼、青干草和玉米青贮）的常规营养成分。结果表明，在进行不同的加工处理后玉米，DM、OM、CP、淀粉、NDF、Ca和P等常规成分的含量无显著变化（P﹥0.05）。试验二 选择3头健康的、年龄、胎次、体重和泌乳期相近，且安装有永久性瘤胃瘘管中国荷斯坦泌乳奶牛为试验动物。采用半体内法研究不同加工处理的玉米和其它饲料原料的瘤胃尼龙袋降解规律。结果表明，玉米经不同加工处理后其瘤胃降解模型参数a、b、c和P值发生了显著的变化。与对照玉米的DM、OM、CP和淀粉的各有效降解率P值相比，膨化玉米、颗粒玉米P值显著或极显著增加，压扁玉米的P值差异不显著（P﹥0.05）（淀粉的P值除外）、烘炒玉米的P值都显著降低（P<0.05）。其它饲料原料的降解参数也不尽相同。豆粕的各指标介于膨化玉米和颗粒玉米之间，胡麻饼与烘炒玉米的各P值十分接近。试验三 用试验二的3头奶牛提供瘤胃液，利用DFCCS-Ⅱ型双外流连续培养系统（即人工瘤胃）进行体外培养，研究日粮配合对能氮同步释放的影响。结果表明，以BCP的合成量为指标时，最佳底物量为45克/罐/天，最佳培养时间为12h；最佳底物组合形式为膨化玉米+豆粕+胡麻饼+麸皮+青干草+玉米青贮；在本试验条件下，泌乳前期的最佳能氮比为37gRDN/kgFOM，泌乳中后期的最佳能氮比为31gRDN/kgFOM。试验四 利用奶牛小肠液冻干粉BIF进行体外研究，测定培养12h时的瘤胃非降解残渣在小肠中的消化情况。结果表明，膨化玉米的DM和淀粉消化率均显著高于其它组（P<0.05），其它各组之间差异不显著（P﹥0.05）。试验五 选择16头年龄、胎次、体重和泌乳期相近的中国荷斯坦泌乳奶牛进行50天的饲养试验。按照相同的能氮比（37gRDN/kgFOM）配制4种日粮（膨化玉米组、颗粒玉米组、烘炒玉米组和对照玉米组），以检测能氮同步日粮的实际应用价值。结果表明，饲喂各组日粮后，产奶量没有显著变化（P﹥0.05），烘炒玉米有降低产奶量的趋势，但差异不显著（P﹥0.05）。与对照日粮相比，各组的乳脂率、乳蛋白、乳糖和总干物质差异不显著（P>0.05），但是烘炒玉米组的乳脂率显著高于颗粒玉米组（P<0.05）。更多还原

【Abstract】 This paper discusses the effects of processed corns on the synchronization of nitrogen and energy release in rumen and on small intestine digestibility in lactating cows. Based on In Vivo, In Sacco and In Vitro, 5 experiments were conducted as follows:In Exp1, corns were processed by physical methods (expanding, pelleting, dry rolling and roasting) and were analyzed with other feedstuffs (including wheat bran, soybean meal, flaxseed meal, hay and corn silage) to determine whether the nutrient contents in processed corns had any changes. The result shows that DM, OM, CP, starch, NDF, Ca and P contents in processed corns have no significant changes compared with that of control corn (P﹥0.05).In Exp 2, three Chinese Holstein lactating cows with permanent ruminal cannulas were used as experimental animals to investigate the regularity of ruminal degradability of processed corns and above-mentioned feedstuffs by nylon bag technique. The result shows that the effective ruminal degradability P values of DM, OM, CP and starch are significantly different among processed corns. Compared with control corn, the effective ruminal degradability P values of expanded and pelleted corns increase significantly (P<0.05 or P<0.01); the P values of roasted corn decrease apparently (P<0.05); while that of dry rolled corn have no significant changes (P﹥0.05). The P values of DM, OM and CP in soybean meal are between expanded and pelleted corns (P﹥0.05); the P values of flaxseed are much alike that of roasted corn (P﹥0.05).In Exp 3, DFCCS-Ⅱdual-flow continuous culture system was used to study the ration formulation on the synchronization of nitrogen and energy release. The result shows that based on BCP synthesis, the suitable substrate amounts is 45g/d in each fermenter, the best cultural time is 12h; the ideal substrate combination is expanded corn+soybean meal+flaxseed meal +hay+corn silage among various combinations; the best nitrogen and energy ratios are 37gRDN/kgFOM in early lactation period, and 31gRDN/kgFOM in mid and late lactation period. In addition, pH values, NH3-N and VFA concentrations are changed in different combinations.In Exp 4, BIF was used to investigate the digestibility of non-degradable ruminal residues of processed corns (after 12h culture in rumen) in small intestine. The result shows <WP=4>that DM and starch digestibilities are different among all processed corns residues. DM and starch digestibilities of expanded corn are significantly higher than that of other groups in small intestine (P<0.05), while no apparently differences are found among other groups (P﹥0.05).In the last experiment, 16 cows in early and midlaction period were selected to conduct a 50 d feeding experiment with four diets (expanded corn, pelleted corn, roasted corn and control corn). The result shows that the average milk yielding per cow has no significant changes when fed the four diets (P﹥0.05). The higher synchronized diets (expanded corn, pelleted corn) do not significantly increase milk production, which is out of expectation; the lower synchronized diet (roasted corn) has the tendency to decrease milk production, but is insignificant (P﹥0.05). Compared with control group, the milk fat, protein, lactose percentages and total solids in other groups have no apparent differences (P﹥0.05), but the fat percentage in the lower synchronized diet is higher than that of the higher synchronized diet (P<0.05), which is consistent with expectation.更多还原