【作者】 于玲玲；

【导师】 杨在宾；

【作者基本信息】 山东农业大学 ， 动物营养与饲料科学， 2004， 硕士

【摘要】 本研究选用安装有永久性瘤胃瘘管、十二指肠近端瘘管和回肠末端瘘管的利木赞×鲁西黄牛杂交一代公牛3头,研究了不同非蛋白氮、硫和铜日粮水平下肉牛营养物质代谢规律及铜最适添加量。试验分3个非蛋白氮和硫水平,每个非蛋白氮和硫水平下设3个铜水平(10mg/kg,25mg/kg,50mg/kg),采用三个3×3拉丁方设计。粗蛋白、能量及其它营养成分均按NRC(1996)标准供给。肉牛营养物质代谢规律研究结果表明:在非蛋白氮和硫水平一定时,随铜添加量的增加,瘤胃液pH变化不显著(P>0.05),氨氮浓度显著提高(P<0.05)。0%尿素和0.150%无机硫,添加1%尿素和0.225%硫的日粮条件下,随铜添加量增加,肉牛微生物蛋白产量显著降低(P<0.05),ADF和NDF胃区降解率,铜添加水平50mg/kg组显著低于10mg/kg和25mg/kg组(P<0.05),说明在这两个非蛋白氮和硫水平下,10mg/kg铜水平,显著提高微生物蛋白的合成和ADF及NDF胃区降解率;日粮中添加2%尿素和0.300%硫时,日粮铜为25mg/kg水平组的微生物蛋白产量最大,并且ADF和NDF胃区降解率显著高于10mg/kg和50mg/kg水平组(P<0.05),说明此非蛋白氮和硫水平下,铜添加水平25mg/kg显著提高微生物蛋白的合成和ADF及NDF胃区降解率。在三个非蛋白氮和硫水平下,小肠ADF和NDF的降解率,各组间差异不显著(P>0.05)。以上结果表明,随着非蛋白氮和硫添加水平的增加,提高日粮铜水平可在一定程度上提高纤维性物质降解率,但是添加50mg/kg的日粮铜无意义。肉牛铜生物学利用率研究结果表明:0%尿素和0.150%无机硫及添加1%尿素和0.225%无机硫的日粮条件下,随着铜水平的增加,血铜浓度、血清铜蓝蛋白和过氧化物歧化酶活力无显著性变化(P>0.05),说明10mg/kg日粮铜即能满足肉牛需要。日粮中添加2%尿素和0.300%无机硫时,添加25mg/kg和50mg/kg日粮铜可显著提高血铜浓度、铜蓝蛋白和过氧化物歧化酶的活力,说明25mg/kg日粮铜能显著提高血铜浓度和铜蓝蛋白及过氧化物歧化酶的活力,50mg/kg日粮铜无意义。 <WP=7>本研究通过对不同非蛋白氮、硫和铜水平下,肉牛瘤胃ADF和NDF降解率、血清铜蓝蛋白和血清过氧化物歧化酶活力、血铜浓度等指标的系统研究,确定不同非蛋白氮和硫水平下,铜的适宜添加量为:0 %尿素和0.150%无机硫时,铜的添加水平为10mg/kg;1%尿素和0.225%无机硫时,铜的添加水平为10mg/kg;2%尿素和0.300%无机硫时,铜的添加水平为25mg/kg。更多还原

【Abstract】 The objective of this experiment was to study the nutrient metabolsm in different diet of NPN and copper levels ,and to determine the requirement of copper in certain NPN and sulfur level.3 health cross-breed(Limousin×Luxi) beef cattle were selected in the study, which were surgically fitted with permanent cannulate in the rumen, the beginning of duodenum and the end of ileum. In this experiment, The concentration of protein, energy and other nutrient ingredients of the diets were given according to NRC(1996) criterion and the diets included 3 NPN and sulfur levels, each NPN and sulfur level has three copper levels(10mg/kg,25mg/kg,50mg/kg). 3×3 Ladin square was adopted in this experiment. The result of the nutrient metabolism showed: In the three NPN and sulfur levels, the pH of the rumen has no remarkable difference in 3 copper levels(P > .05),the concentration of NH3-N enhanced according to the increasing of copper levels;In the diets of 0% urea and 0.150% sulfur,1% urea and 0.225% sulfur,the production of MCP decreased according to the copper gain(P < .05),the degradation rate of ADF and NDF in 50mg/kg copper levels is lower remarkably than 10mg/kg and 25mg/kg copper levels;In the diet of 2% urea and 0.300% sulfur and copper level is 25mg/kg, the maximum MCP production occurred and the degradation rate of ADF and NDF is higher significantly than 10mg/kg and 50mg/kg copper levels(P < .05). This tells us that 25mg/kg copper level can increase the production of MCP and degradation rate of fiber. In every NPN and sulfur diet, the degradation rate of <WP=9>ADF and NDF in intestine has no remarkable difference (P > .05). From the analysis above, we can conclude that copper level 50mg/kg is nonsense.The result of copper bioavailability showed: In the diet of 0% urea and 0.150% sulfur,1% urea and 0.225% sulfur, the content of blood copper, the activity of serum Cp and SOD had no notable difference between the three copper levels(P > .05),this indicates 10mg/kg copper level can meet the need of beef. In the diet of 2% urea and 0.300% sulfur, 25mg/kg copper level can increase the content of blood copper, activity of Cp and SOD significantly, and it is suitable.By the result of degradation rate of ADF and NDF in beef rumen, activity of serum Cp and SOD, content of blood copper in this experiment, we can make a conclusion that the most suitable copper level in different NPN and sulfur level is:The copper level is 10mg/kg in 0% urea and 0.150% sulfur level;The copper level is 10mg/kg in 1% urea and0.225% sulfur level;The copper level is 10mg/kg in 2% urea and 0.300% sulfur level.更多还原