PSIII-35 Effects of dietary macronutrient profile on apparent total tract macronutrient digestibility and fecal metabolites of female dogs after spay surgery

Abstract

Abstract Obesity reduces the quality and length of life of companion animals. Spaying increases risk, but dietary modification may attenuate obesity and related co-morbidities. The objective of this study was to determine the effects of specially formulated diets on apparent total tract macronutrient digestibility (ATTD) and fecal metabolites of female dogs after spay surgery. All procedures were approved by the University of Illinois Institutional Animal Care and Use Committee prior to experimentation. Twenty-four dogs were spayed and randomly allotted to three experimental diets: 1) moderate-protein, moderate-fiber diet (control; COSP), 2) high-protein, high-fiber diet (HP-HF), or 3) high-protein, high-fiber diet plus omega-3 fats (HP-HF-O). Four dogs were sham-operated and fed the control diet (COSH). Dogs were fed to maintain BW for 12 weeks after spay, then allowed to consume twice that amount for another 12 weeks. Change from baseline data were analyzed statistically, with P < 0.05 being significantly different. Food intake in dogs fed HP-HF or HP-HF-O was greater than COSH dogs, but COSP dogs were intermediate. Fat and organic matter digestibilities were lower in dogs fed HP-HF or HP-HF-O compared with COSH and COSP dogs. Fecal dry matter percentage and volume increases were greater in HP-HF and HP-HF-O dogs than COSH and COSP dogs. HP-HF and HP-HF-O dogs had higher fecal acetate than COSH or COSP dogs. Fecal butyrate tended to be greater (P = 0.08) in HP-HF dogs than COSH dogs. COSH and HP-HF-O dogs had lower fecal valerate than COSP dogs, while fecal ammonia tended to be higher (P = 0.05) in HP-HF-O than COSP and HP-HF dogs. Fecal total short-chain fatty acid (SCFA) increases in HP-HF-O dogs were higher than COSH dogs. Our results indicate that a high-protein, high-fiber diet can reduce energy content by reducing fat digestibility without affecting protein digestibility, modulate fecal SCFA concentrations, and decrease fecal branched-chain fatty acid.