Metcalf J A, Sutton J D, Cockburn J E, Napper D J, Beever D E
Agriculture and Food Research Council Institute of Grassland, Maidenhead, England.
J Dairy Sci. 1991 Oct;74(10):3412-20. doi: 10.3168/jds.S0022-0302(91)78531-7.
Four lactating dairy cows received arterial infusions of insulin (1.41 U/h), an AA mixture (threonine, methionine, leucine, phenylalanine, and lysine at 5.87, 1.90, 3.55, 2.17, and 4.21 mmol/h, respectively), and a combination of the two in a 4 x 4 Latin square. The infusions were performed over a 3-d period directly into the extra pudic artery on both sides of the mammary gland, and samples were taken simultaneously of the downstream extra pudic arterial blood and also of subcutaneous abdominal venous blood. Blood flow was measured by dye dilution using p-amino-hippuric acid and was increased by 37% by infusion of insulin plus AA (P less than .05). Infusions of AA tended to increase the arteriovenous difference and uptake of the infused AA (P less than .05 for phenylalanine) and had varying effects on the uninfused AA. Inclusion of insulin in the AA infusion tended to increase uptake of infused AA, whereas infusions of insulin alone tended to decrease uptake. There were no significant effects of infusion on milk yield or composition.
四头泌乳奶牛按4×4拉丁方设计接受动脉输注胰岛素（1.41单位/小时）、氨基酸混合物（苏氨酸、蛋氨酸、亮氨酸、苯丙氨酸和赖氨酸，分别为5.87、1.90、3.55、2.17和4.21毫摩尔/小时）以及两者的组合。输注在3天内直接注入乳腺两侧的阴部外动脉，同时采集下游阴部外动脉血和皮下腹部静脉血样本。使用对氨基马尿酸通过染料稀释法测量血流量，胰岛素加氨基酸输注使血流量增加了37%（P<0.05）。氨基酸输注倾向于增加动静脉差异和输注氨基酸的摄取量（苯丙氨酸P<0.05），对未输注的氨基酸有不同影响。在氨基酸输注中加入胰岛素倾向于增加输注氨基酸的摄取量，而单独输注胰岛素则倾向于减少摄取量。输注对产奶量或成分没有显著影响。
