|Title:||Apparent total tract macronutrient digestibility, fecal characteristics, urinalysis, fecal metabolites, serum chemistry, and voluntary physical activity levels of healthy adult dogs fed extruded, mildly cooked and raw foods
|Abstract:||The pet food market continues to be strong, with much of the growth coming from super- premium foods and those with novel formats or processing methods. In addition to canned and extruded diets, lightly cooked and raw diets are available today. Despite the increase in their popularity, little research has been performed on such diets. The objective of this study was to determine the apparent total tract macronutrient digestibility (ATTD), fecal characteristics and metabolites, serum chemistry metabolic profile, urinalysis, and voluntary physical activity levels of adult dogs fed the following commercial dog diets: 1) Purina Dog Chow (DC), as the control diet; 2) Freshpet Vital Balanced Complete Nutrition (CN); 3) Freshpet Roasted Meals (RM); 4) Freshpet Vital Raw (VR). All procedures were approved by the University of Illinois Institutional Animal Care and Use Committee prior to the study. Eight dogs (mean age = 3.6 yr ± 0.29; mean body weight (BW) = 13.0 kg ± 0.84) were used in a replicated 4x4 Latin square design. Each period consisted of 28 d, with a 14-d adaptation phase followed by a 7-d phase for measuring voluntary physical activity, a 1-d adaptation phase to metabolic cages, a 5-d phase for fecal and urine collection, and 1-d for blood collection. Fresh fecal samples were collected for pH, moisture, and metabolite measurements. Food was fed twice daily and at a rate to maintain BW. All data were analyzed statistically by mixed models of SAS. Dry fecal output and ATTD of dry matter (DM) and organic matter (OM) were not affected by treatment; however, ATTD of crude protein (CP) was greater (P<0.05) for dogs fed CN than dogs fed VR, with dogs fed RM being intermediate. Dogs fed CN or RM had greater (P<0.05) ATTD of CP than dogs fed DC. ATTD of fat was greater (P<0.05) by dogs fed VR than dogs fed RM, with dogs fed CN being intermediate. Dogs fed CN, VR, or RM had a greater (P<0.05) ATTD of fat than dogs fed DC. Dogs fed CN had higher (P<0.05) fecal pH than dogs fed VR, with dogs fed RM and DC being intermediate. Dogs fed DC, CN or RM had higher (P<0.05) fecal DM% than dogs fed VR. Dogs fed VR had a higher (P<0.05) fecal acetate concentration than dogs fed RM, with dogs fed CN and DC being intermediate. Dogs fed RM had higher (P<0.05) fecal indole and total phenol and indole concentrations than dogs fed CN, VR and DC. Dogs fed VR had a higher (P<0.05) fecal ammonia concentration than dogs fed RM, CN and DC while dogs fed RM had a higher (P<0.05) ammonia concentration than dogs fed DC, with dogs fed CN being intermediate. All other fecal metabolites were not affected by treatment. Most serum metabolites and urinary measures were within reference ranges for dogs fed all dietary treatments and were not affected by diet (P>0.05). Serum triglycerides were within reference ranges, but greater (P<0.05) for dogs fed DC than dogs fed CN or VR, with those fed RM being intermediate. All diets were well tolerated and dogs remained healthy throughout the study. In conclusion, the lightly cooked and raw diets tested were highly palatable, highly digestible, reduced blood triglycerides, and maintained fecal quality and serum chemistry.