PDF(Pubmed)
Abstract：
This study investigated the effects of the dietary protein level and rumen-protected methionine and lysine (RPML) on the growth performance, rumen fermentation, and serum indexes of yaks. Thirty-six male yaks were randomly assigned to a two by three factorial experiment with two protein levels, 15.05% and 16.51%, and three RPML levels: 0% RPML; 0.05% RPMet and 0.15% RPLys; and 0.1% RPMet and 0.3% RPLys. The trial lasted for sixty days. The results showed that the low-protein diet increased the DMI and feed conversion ratio of yaks. The diet supplemented with RPML increased the activities of IGF1 and INS and nutrient digestibility. The high-protein diet decreased the rumen butyrate concentration and increased the rumen isovalerate concentration. The low-protein diet supplemented with RPML increased the rumen pH and the concentrations of total volatile fatty acids, butyrate and NH3-N; the high-protein diet supplemented with a high level of RPML decreased the rumen pH and the concentrations of isobutyrate, isovalerate, propionate and NH3-N. The low-protein diet supplemented with RPML increased the total antioxidant capacity and glutathione peroxidase activity, along with the concentrations of malondialdehyde and amino acids such as aspartic acid, lysine, cysteine, etc. In conclusion, a low-protein diet supplemented with RPML is beneficial for rumen and body health, physiological response, and metabolic status in yaks.
摘要：
本研究研究了饲粮蛋白质水平和过瘤胃蛋氨酸和赖氨酸（RPML）对生长性能的影响。瘤胃发酵，牦牛血清指标。36只雄性牦牛被随机分配到两个蛋白质水平的2乘3阶乘实验中，15.05%和16.51%，和三个RPML水平:0%RPML;0.05%RPMet和0.15%RPLys;以及0.1%RPMet和0.3%RPLys。审判持续了六十天。结果表明，低蛋白日粮提高了牦牛的DMI和饲料转化率。添加RPML的日粮增加了IGF1和INS的活性和养分消化率。高蛋白饮食降低了瘤胃丁酸浓度，增加了瘤胃异戊酸浓度。补充RPML的低蛋白饮食增加了瘤胃pH和总挥发性脂肪酸的浓度，丁酸和NH3-N;补充高水平RPML的高蛋白饮食降低了瘤胃pH和异丁酸的浓度，异戊酸,丙酸盐和NH3-N。补充RPML的低蛋白饮食增加了总抗氧化能力和谷胱甘肽过氧化物酶活性，随着丙二醛和氨基酸如天冬氨酸的浓度，赖氨酸，半胱氨酸,等。总之,补充RPML的低蛋白饮食对瘤胃和身体健康有益，生理反应，牦牛的代谢状况.
