Effect of protein consumption on body weight maintenance, body composition, protein synthesis and catabolism of adult cats

Abstract

The cat diet is characterized by high requirement for protein compared with omnivores and herbivores, and consumption of animal preys in the natural diet, with high levels of protein and fats and low levels of carbohydrates. There are studies about the starch digestion of these animals, but little has been researched about the effects of protein to starch ratios in the metabolism. The study aims to evaluate the effect of protein consumption on body weight maintenance, body composition, protein synthesis and catabolism of adult cats and is organized into two 4x4 Latin square designs, each with four extruded diets with different proportions of protein (CP) and starch (CHO): 20% of CP and 48.5% of CHO; 34% of CP and 33.5% of CHO; 48% of CP and 18.5% of CHO and 62% of CP and 3.5% of CHO, all within the recommended nutritional tables (NCR, 2006), in four seven-week periods and four cats, totaling eight replicates for each diet. The following parameters will be evaluated: consumption of metabolizable energy for body weight maintenance, body composition (lean body mass and fat mass) of the animals at the beginning and at the end of the study using deuterium oxide; nutrient and energy digestibility of the diets; protein metabolism through nitrogen balance, 24h urinary excretion of urea, muscle catabolism (measuring urinary 3-methyl-histidine), retinol binding protein and lean body mass. Data will be evaluated by polynomial contrasts and Paried T-test (P<0.05). (AU)