[The effect of the protein level of feed on the energy maintenance requirement of rats during the course of growth and after the conclusion of the intensive growth phase using different feeding regimens].

In two experiments with male Wistar rats energy metabolism was measured on the feeding level of maintenance in the course of growth and in various adult periods after the application of feed mixtures with various protein-carbohydrate quotas (10, 40 and 70% crude protein) according to two different feeding regimes. While there was a change of protein levels between the animal groups in periods 1 to 3 and 8 to 10 from one period to the other, the protein levels in periods 4 to 7 and 11 to 13 remained the same for each animal group. Irrespective of the feeding regime, a dependence of the energy maintenance requirement on the nutrients according to the expected values was measured, which result from the different efficiency of ATP synthesis in the oxidative degradation of the nutrients. On an average of the periods maintenance requirement amounted to 357 +/- 21, 399 +/- 16 and 443 +/- 28 kJ/kg LW0.75.d (experiment 1) and 350 +/- 29, 383 +/- 34 and 442 +/- 30 kJ/kg LW0.75.d (experiment 2) for 10, 40 and 70% crude protein in the feed. The relation between the maintenance requirement values was 100:112:124 and 100:109:126. This contrasts with the relative expected values of 100:108:115 and 100:109:116.