2016 ACVIM Forum Research Abstract Program

WHEN FED FOODS WITH SIMILAR PALATABILITY, CATS CHOOSE 30%, DOGS 23% OF CALORIES AS PROTEIN. Dennis Jewell 1 , Jodi Vondran 1 , Melissa Vanchina 1 , Jean Hall 2 . 1 Hill's Pet Nutrition, Inc., Topeka, KS, USA, 2 Oregon State University, Corvallis, OR, USA Dogs and cats have specific taste preferences that are influenced by macronutrient composition and physical characteristics of food, as well as presence or absence of specific taste imparting compounds (palatability enhancers). This study investigated the relationship of food choice on macronutrient composition and that choice on subsequent plasma amino acid concentrations. Experimental foods for dogs and cats were individually prepared to have similar palatability through manipulations of factors independent of macronutrients. Foods with similar palatability preference for their respective populations as a whole were then investigated for intake choice using 20 dogs with varying body fat composition (mean, 3.9 kg; SD, 0.9 kg; range, 2.4-6.2 kg;) and 27 cats (mean body fat composition, 1.4 kg; SD, 0.9 kg; range 0.3-2.2 kg). Subsequent effects of food choice on serum amino acids were also determined. Four completely balanced foods were available to dogs and cats at all times. The four varied in macronutrient content: Food 1: high protein (33% of calories from protein for dogs; 42% for cats); Food 2: high fat (54% of calories from fat for dogs; 44% for cats); Food 3: high carbohydrates (56% of calories from carbohydrate for dogs; 52% for cats); and Food 4: blended macronutrients. Dogs on average chose to consume 23.0% calories from protein (SD, 1.5%; range 20-26%) whereas cats chose 30.3% of calories from protein (SD, 4%; range 24-38%). Body composition influenced their choice of calories from protein. In dogs, there was a positive relationship between body fat and percent calories consumed as protein (r = 0.56; P = 0.02). There was no relationship between lean body mass and percent calories consumed as protein (r = 0.06; P = 0.82). Overall, dogs with high body fat showed the highest preference for dietary calories from protein. In cats, both body fat and lean body mass were negatively associated with calories consumed as protein (P = 0.04; P = 0.02, respectively), with a positive association for the interaction (P = 0.02). Overall, cats with high body fat and high lean body mass showed the highest preference for dietary calories from protein. Dogs had higher circulating amino acid concentrations of threonine, methionine, isoleucine, and valine (P < 0.05) compared with cats, the later which had higher circulating amino acid concentrations of isoleucine, valine, tyrosine, phenylalanine, and histidine (P < 0.05). In both dogs and cats there was no effect of protein intake on circulating essential amino acid concentrations. Increased intake of calories as protein was associated with increasing plasma ornithine (dogs only) and citrulline (dogs and cats) concentrations (P < 0.05). In summary, given the opportunity to choose between foods with similar palatability, cats chose to consume 30.3% and dogs 23.0% of their calories as protein. Although there were species differences between circulating amino acid concentrations indicating metabolic shifts associated with protein intake, there were no changes in circulating essential amino acid concentrations. The purpose of this double masked, controlled multicenter clinical trial was to determine the impact of a food with ingredients designed to have