【作者】 郭玉琴；

【导师】 王加启；

【作者基本信息】 中国农业科学院 ， 动物营养与饲料科学， 2006， 博士

【摘要】 采用不同材料配比保护得到RPMet和RPLys的基础上，对蛋氨酸和赖氨酸的保护和利用效果进行了评价。通过RPMet和RPLys的稳定性研究，选定6种RPMet和4种RPLys。蛋氨酸分别以丙烯酸树脂Ⅳ号(M1)；丙烯酸树脂Ⅳ号和乙基纤维素(M2)；丙烯酸树脂Ⅳ号和乙基纤维素及羟丙基甲基纤维素(M3)；乙基纤维素(M4)；丙烯酸树脂Ⅳ号和氢化植物油(M5)；氢化植物油(M6)包被；赖氨酸分别以丙烯酸树脂Ⅳ号和乙基纤维素(L1)；丙烯酸树脂Ⅳ号和羟丙基甲基纤维素(L2)；丙烯酸树脂Ⅳ号和氢化植物油(L3)；乙基纤维素和氢化植物油(L4)包被；10种产品进行了体外法和尼龙袋法稳定性检验。结果表明，用尼龙袋在4头荷斯坦奶牛瘤胃中培养4、8、24、48h，丙烯酸树脂Ⅳ号和氢化植物油保护的蛋氨酸(M5)及保护的赖氨酸(L3)释放率最低，分别为11.70％～50.70％，35.70％～72.10％，其在pH6.6缓冲溶液中培养相应时间的释放率分别为24.67～38.44％，42.05～75.02％，2种产品体外法与尼龙法测定结果相关性显著，相关系数(R~2)分别为0.8675和0.9630；在真胃和小肠及在pH2.4缓冲溶液中的释放率均为100％。通过计算M5和L3在瘤胃的有效降解率分别为30.49％和51.04％，相应通过瘤胃进入小肠释放的比率为69.51％和48.96％。通过瘤胃补充RPMet和十二指肠灌注蛋氨酸研究了蛋氨酸的保护和利用效果。选用4头瘘管奶牛，采用4×4拉丁方设计。结果表明，瘤胃补充用丙烯酸树脂Ⅳ号和氢化植物油保护的蛋氨酸15g(10g蛋氨酸)，可显著提高奶牛血浆游离蛋氨酸浓度(6.55ug／ml)，是十二指肠灌注10g蛋氨酸(9.24ug／ml)的70.88％，基础日粮和瘤胃补充10g蛋氨酸血浆游离蛋氨酸浓度分别为2.71ug／ml，3.20ug／ml。补充RPMet和灌注蛋氨酸，乳腺对动脉血浆中游离蛋氨酸的摄取率分别为0.85％和0.43％。补充RPMet能显著增加血浆尿素氮、奶中尿素氮(P＜0.05)，但对泌乳中后期奶牛产奶量、乳成分和瘤胃液pH值、氨氮、VFA浓度及氮的消化利用没有显著影响(P＞0.05)。通过瘤胃补充RPLys及十二指肠灌注赖氨酸研究了赖氨酸的保护和利用效果。选用4头瘘管肉牛，采用4×4拉丁方设计，结果表明，瘤胃补充用丙烯酸树脂Ⅳ号和氢化植物油保护的赖氨酸26g(15g赖氨酸)，可显著提高肉牛血浆游离赖氨酸浓度(11.18ug／ml)，为十二指肠灌注15g赖氨酸(16.97ug／ml)的66.61％，基础日粮和瘤胃补充15g赖氨酸血浆游离赖氨酸浓度分别为7.31ug／ml，8.00ug／ml。瘤胃补充RPLys能显著增加血浆尿素氮浓度(P＜0.05)，对瘤胃液pH值、氨氮和VFA浓度及氮的消化利用无显著影响(P＞0.05)。更多还原

【Abstract】 Experiments were conducted to study the producing techniques and the effectiveness of protection and application of Rumen bypass methionine(RPMet),lysine(RPLys).Six RPMet and four RPLys products were obtained and their stability were evaluated by in vitro and in situ methods. Six RPMet were protected by polyoxylateⅣ(M1); polyoxylateⅣand ethyl-cellulose (M2); polyoxylateⅣand ethy1-cellulose and hydroxyprpoyl methylcellulose (M3); ethyl-cellulose (M4) dividely; polyoxylateⅣand hydrogenated vegetable tallow (M5); hydrogenated vegetable tallow (M6). Four RPLys were protected by polyoxylateⅣand ethyl-cellulose (L1); polyoxylateⅣand hydroxyprpoyl methylcellulose(L2); polyoxylateⅣand hydrogenated vegetable tallow (L3); ethyl-cellulose and hydrogenated vegetable tallow (L4) dividely. The results showed that nitrogen release rate were 11.7%～50.7% and 42.05%～75.02% respectively for M5 and L3 when incubated for 4, 8, 24 and 48 h in the rumen of four Holstein Friesian cows. Whereas the nitrogen release rate were 24.67～38.44% and 42.05～75.02% respectively when incubated for 4, 8, 24 and 48 h in the pH 6.6 buffer solution, There was a significant positive linear relationship between the degradability of RPMet and RPLys in rumen and that in pH 6.6 buffer solutions. The correlation coefficients were 0.8675 and 0.9630 for M5 and L3, respectively. Nitrogen release rate in abomasum, small intestine and pH2.4 buffer solution were all 100%. The effective degradability of M5 and L3 in the rumen were 30.49% and 51.04%, and 69.51% methionine and 48.96% lysine could enter small intestine accordingly.The effectiveness of the protection and application of RPMet were further evaluated by using 4 cannulated cows with a 4×4 Latin square experiment design. The results indicated that supplementing methionine coated with the polyoxylateⅣand hydrogenated vegetable tallow through rumen cannular could significantly improve the concentration of plasma free methionine in the jugular vein (6.55ug/ml) (P＜0.05), which is about 70.88% of that with duodenal infusions of methionine(9.24ug/ml). The concentrations of plasma free methionine were 2.71ug/ml and 3.20ug/ml of cows fed either with the basal diets or supplying Met in the rumen. The results also showed that supplying RPMet in the rumen could significantly increase the concentrations of free methionine in artery plasma and vena plasma of mammary gland (P＜0.05), whereas the concentrations were lower than that of infusing methionine into duodenum (P＜0.05).The extraction efficiency of methionine in artery plasma within mammary gland were 0.85% and 0.43% respectively. Supplementing RPMet in the rumen could significantly increase the concentrations of plasma urea nitrogen and milk urea nitrogen (P＜0.05). However milk yield, milk component, digestion and utilization of nitrogen, ruminal pH,the concentration of NH3-N and VFA were not significantly affected (P＞0.05).By comparing the supplementing Protected-Lysine to rumen and infusing Lysine into duodenum, the effectiveness of the protection and application of RPLys were further evaluated. Four beef catties with rumen, duodenum and ileum cannulars were used in a 4×4 Latin square experiment design. The results showed that supplying lysine coated with the polyoxylateⅣand hydrogenated vegetable tallow in the rumen could significantly improve the concentration of plasma free lysine in the jugular vein (11.18ug/ml) (P＜0.05), which is about 66.61% of that with duodenal infusions of lysine(16.97ug/ml). The concentrations of free lysine were 7.31ug/ml and 8.00ug/ml with the basal diets and supplementing of Lys in the rumen respectively. Supplementing RPLys in the rumen could significantly increase plasma urea concentration (P＜0.05), whereas had no effects on the ruminal pH, NH3-N, VFA, digestion and utilization of nitrogen (P＞0.05).更多还原