保护性蛋氨酸对中国荷斯坦奶牛血浆代谢产物及生产性能的影响

选择25头中国荷斯坦奶牛,分成对照组,试验一组(添加30 g DL-蛋氨酸),试验二组(添加45 g保护性蛋氨酸),试验三组(添加30 g DL-蛋氨酸+50 g L-赖氨酸)和试验四组(添加45 g保护性蛋氨酸+50 g L-赖氨酸)进行饲养试验。试验表明:试验四组和试验二组产奶量显著(P<0.05)高于对照组,分别提高6.31 %和6.73 %,其他组差异不显著(P>0.05);试验四组和试验二组乳脂率显著(P<0.05)高于对照组,分别提高6.25 %和6.55 %;并且试验四组和试验二组乳脂率也显著(P<0.05)高于试验一组。乳蛋白、体细胞数、全脂固形物和非脂固形物各组间差异不显著(P>0.05)。试验四组和试验二组血浆白蛋白和总蛋白显著高于对照组(P<0.05),其它各组差异不显著(P>0.05)。试验二组血浆尿素氮(PUN)显著低于对照组和试验一组(P<0.05),其他各组差异不显著(P>0.05)。血浆游离脂肪酸和总氨基酸浓度各组差异不显著(P>0.05)。由此得出结论:一方面,保护性蛋氨酸(RPMet)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,保护性蛋氨酸的降解部分改善了瘤胃的发酵,促进瘤胃微生物的合成,这两方面的作用提高了奶牛的产奶量和乳成分。

Effects of ruminally protected methtionine on plasma metabolites and production performance in Chinese Holstein cows

Twenty-five individuals of Chinese-Holstein cows with high-producing were arranged randomly into five groups, i.e. control, treatment 1 (added 30 gDL-Met), treatment 2 (added 45 g RPMet), treatment 3 (added 30 g DL-Met+50 g L-Lys) and treatment 4 (added 45 g RPMet +50 g L-Lys), aiming to reveal the effects of ruminally protected methtionine(RPMet) with different treatments on blood plasma metabolites, milk production and milk constituents. The results showed that the milk production in treatment 4 and treatment 2 (P<0.05) increased by 6.31 % and 6.73 % respectively. Milk fat percentages in treatment 4 and treatment 2 were 6.25 % and 6.55 % respectively greater than control (P<0.05) and significantly higher than treatment 1 (P<0.05). Whereas five groups had no differences (P>05) in milk protein percentages, somatic cell counts, solids and solids-not-fat in milk. Plasma albumin and total protein were higher (P<0.05) in treatment 4 and treatment 2 than other groups, and PUN of treatment 2 was the lowest (P<0.05) in five groups. TAA and NEFA were not affected by supplemental AA (P>0.05). It can be concluded that ruminally protected methtionine(RPMet) survived rumen microbial degradation to provide a rumen-protected form of methionine(Met) , and it enhanced ruminal fermentation and improved microbe synthesis, so milk production and composition of milk were improved.