【作者】 高红建；

【导师】 张力；

【作者基本信息】 中国农业科学院 ， 动物营养与饲料科学， 2002， 硕士

【摘要】 选用3只装有瘤胃瘘管和T型十二指肠瘘管的生长滩羊，采用3×3拉丁方试验设计，测定瘤胃添加氮-羟甲基蛋氨酸钙（N-HMM-Ca）对瘤胃内环境，饲料养分的消化代谢，微生物蛋白的合成及血浆参数的影响。进行了三个处理，基础饲粮（40％精料，60％粗料）作为对照组，Met组和N-HMM-Ca组在基础饲粮的基础上，3g DL-Met和4.67g N-HMM-Ca（相当于3g DL-Met）分别添加到瘤胃中。试验结果表明，瘤胃添加N-HMM-Ca和Met显著降低了瘤胃液NH_3-N浓度（p＜0.05），其平均值，N-HMM-Ca组显著低于对照组和Met组（p＜0.05）；瘤胃液总的VFA无明显差异，但乙酸和丁酸有增加趋势（p＜0.1），瘤胃液pH值不受影响。瘤胃添加N-HMM-Ca和Met后，显著提高了DM、OM、CP、NDF和ADF在全消化道中的消化率（p＜0.05），N-HMM-Ca和Met二处理间差异不显著（p＞0.05）。在瘤胃中添加N-HMM-Ca后，影响进入十二指肠食糜中N流量及组成，N-HMM-Ca组的非氨态氮流量比Met组和对照组显著提高（p＜0.05），而氨态氮恰好相反，微生物氮的流量比对照组高28.56％（p＜0.05），比Met组高11.01％（p＞0.05）。N-HMM-Ca的添加减少了尿N的排出，提高了N的沉积（p＜0.05），与Met添加组和对照组相比，分别提高37.95％和76.57％。瘤胃添加N-HMM-Ca后，血浆中游离Met浓度比对照组显著升高（p＜0.01），也有高于Met组的趋势（p＜0.10）。血浆中含硫AA（Met+Cys）与Met组和对照组相比，有增高趋势（p＜0.1），同样N－HMM-Ca的添加有降低血浆尿素N的趋势（p＜0.1），增加血浆白蛋白和总蛋白浓度的趋势（p＜0.1），血浆中NEFA三个处理组之间无显著变化，由此得出结论：一方面N-HMM-Ca的一部分能避免瘤胃微生物的降解，以保护性Met的形式提供给瘤胃后Met，另一方面，N-HMM-Ca的降解部分改善瘤胃的发酵，促进微生物蛋白的合成。更多还原

【Abstract】 In a 3X3 Latin square design trial, 3 Tan-yang Sheep equipped with ruminal and T-typeduodenal cannulas were given a basal diet (40% concentrate, 60% roughage) without (control)or with rumen addition of 3g DL-methionine or 4.67g N-HMM-Ca(equivalent to 3gDL-methionine) to study the effect of N-hydroxymethyl-DL-methionine-C (N-HMM-Ca )onrumen enviroment,digestion metabolism of diet nutrients,microbia1 protein synthesis and b1oodplasma parameters .The results showed that ammonia N concentrarion in the rumen fluid wasdecreased when N-HMM-Ca or Met were added directly into rumen,moreover,average ruminalammonia N concentration was lower with addition of N-HMM-Ca than that with Met andcontrol.A1though pH va1ue and total VFA concentration in the rumen fluid were not affected byN-HMM-Ca addition and Met addition,Ruminal acetic acid and butyric acid concentrations tendedto eIevate,compared with controI.Adding N-HMM-Ca or Met increased total digestibilites of DM.OM. CP. ADF and NDF in sheep,with no significant difference betWeen N-HMM-Ca addition andMet addition. Duodenal NAN flow was highef, and Duodenal ammonia N flow was lower,Withaddition of N-HMM-Ca than Met and Control. When N- HMM-Ca was added into the rumen, flowof microbial N into duodenum was increased by 28.56%(p<0.05) and ll.0l%(p>0.05)respectively,compared with control and Met addition.N retention in sheep for N- HMM-Catreatment was 37.95% and 76.57% greater than that for Met treatment and controlrespectively,,mainly due to decreased urinary N. blood plasma methionine concentration washigher with addition of N-HMM-Ca was higher than that with control (p<0.01)and that with Metaddition(p<0.l0).Compared with Met treatment and control,blood plasma SAA(Met+Cys),.a1bumin and total protein tended to increase,and PUN tended to decrease by N-HMM-Caaddition.No significant change was fOund in plasma NEFA concentration.It can be concluded that a -’fraction N-HMM-Ca survives rumen microbial degradation to provide a rumen-protected form ofmethionine,at the same time that it enchanced ruminal fermentation and improved microbialprotein synthesis.更多还原