Fischer J E, Canolty N L
J Nutr. 1983 Jun;113(6):1095-103. doi: 10.1093/jn/113.6.1095.
Male, Sprague-Dawley rats at 15 and 25 months of age were fed for 21 days diets containing 2, 3, or 4% casein supplemented with 0.078 g methionine/g casein at three levels of intake. Metabolizable energy intakes (MEI) required to maintain energy of total carcass and carcass protein were predicted from regression equations relating change in energy of total carcass and carcass protein to MEI. Mean MEI required to maintain energy of total carcass for 15- and 25-month-old rats, respectively, were 112 versus 88, 99 versus 76 and 94 versus 74 kcal/(kg0.75 X day) for 2, 3 and 4% casein, respectively. Mean MEI required to maintain energy of carcass protein for 2, 3 and 4% casein were 103, 98 and 85 kcal/(kg0.75 X day) for the 15-month-old animals and 93, 90 and 62 kcal/(kg0.75 X day) for the 25-month-old animals. Confidence intervals for mean maintenance energy intakes were wide and overlapped as age and casein concentration were varied. However, trends were evident. For both ages, as casein concentration increased, mean requirements decreased, and at each casein concentration, the 25-month-old animals had lower mean requirements than the 15-month-old animals.
雄性斯普拉格-道利大鼠，15月龄和25月龄，分别喂食含2%、3%或4%酪蛋白的日粮21天，日粮中添加0.078 g蛋氨酸/g酪蛋白，设三个摄入量水平。根据全胴体能量和胴体蛋白质能量变化与代谢能摄入量（MEI）的回归方程，预测维持全胴体能量和胴体蛋白质所需的代谢能摄入量。15月龄和25月龄大鼠维持全胴体能量所需的平均MEI，对于2%、3%和4%酪蛋白日粮，分别为112与88、99与76以及94与74 kcal/(kg0.75×天)。对于2%、3%和4%酪蛋白日粮，15月龄动物维持胴体蛋白质能量所需的平均MEI分别为103、98和85 kcal/(kg0.75×天)，25月龄动物分别为93、90和62 kcal/(kg0.75×天)。随着年龄和酪蛋白浓度的变化，平均维持能量摄入量的置信区间较宽且有重叠。然而，趋势是明显的。对于两个年龄组，随着酪蛋白浓度增加，平均需求量降低，并且在每个酪蛋白浓度下，25月龄动物的平均需求量低于15月龄动物。
