González J, Rodríguez C A, Centeno C, Lamnari F
Departamento de Producción Animal, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Politécnica de Madrid, Spain.
Reprod Nutr Dev. 2000 Nov-Dec;40(6):579-86. doi: 10.1051/rnd:2000101.
Rumen degradation kinetics and effective degradability of individual amino acids, total analysed amino acids (TAA) and crude protein (CP) of soybean meal were measured on four rumen-cannulated wethers using the nylon bag technique. Microbial contamination of the incubated residues was corrected using a continuous 15N intraruminal infusion and isolated solid associated bacteria as a reference sample. TAA showed a lower soluble fraction (14.9 vs. 20.8%; P < 0.01), a similar insoluble-degradable fraction (79.0 vs. 79.2%) and a higher degradation rate (11.5 vs. 8.4% x h(-1); P < 0.05) than CP. As a consequence, effective degradability was similar for TAA and CP (74.7 vs. 75.7%). Degradability values of individual amino acids varied moderately (range: +/-6% of TAA degradability). Valine, isoleucine, leucine, alanine, aspartic acid and tyrosine showed significantly lower degradability than TAA, while the opposite effect was observed for histidine, threonine and glutamic acid. Degradability of individual amino acids was related to their soluble fraction (r = 0.877; P<0.001).
采用尼龙袋技术，对4头安装瘤胃瘘管的阉羊测定了豆粕中单个氨基酸、总分析氨基酸（TAA）和粗蛋白（CP）的瘤胃降解动力学及有效降解率。使用连续瘤胃内注入15N和分离的固体相关细菌作为参考样品，对培养残渣的微生物污染进行校正。与CP相比，TAA的可溶性部分较低（14.9%对20.8%；P<0.01），不可溶性可降解部分相似（79.0%对79.2%），降解率较高（11.5%对8.4%×h-1；P<0.05）。因此，TAA和CP的有效降解率相似（74.7%对75.7%）。单个氨基酸的降解率变化适中（范围：TAA降解率的±6%）。缬氨酸、异亮氨酸、亮氨酸、丙氨酸、天冬氨酸和酪氨酸的降解率显著低于TAA，而组氨酸、苏氨酸和谷氨酸则相反。单个氨基酸的降解率与其可溶性部分相关（r = 0.877；P<0.001）。
