PSI-2 - Evaluation of sorghum pericarp varieties on blood parameters and antioxidant capacity in healthy adult dogs

Abstract: Ingredients that provide health benefits are popular in the pet food industry. Sorghum contains polyphenols which are found in the pericarp. These polyphenols may provide health benefits due to their antioxidant properties, which increase the benefit of sorghum in pet food. Few pet food studies have evaluated the antioxidant capacity of sorghum differing in pericarp color. The objective of this study was to evaluate the effect of sorghum varieties on blood parameters and antioxidant capacity in dogs. Nutritionally complete experimental diets were extruded with a 50% inclusion of either rice, white sorghum A, burgundy sorghum, or white sorghum B. Twelve dogs were fed dietary treatments in a replicated 4 x 4 Latin square design consisting of 14-day periods. Three milliliters of blood were taken from each dog prior to starting the trial for baseline antioxidant capacity. At the end of each period, three milliliters of blood were taken from each dog and stored at -80°C until further analysis. Blood samples were analyzed for complete blood count (CBC), chemistry profiles (Kansas State University Veterinary Diagnostics Lab, Manhattan, KS), and oxygen radical absorbance capacity (ORAC) was measured by kit in blood plasma. Data was analyzed using a mixed model with statistical analysis software (SAS version 9.4, SAS Institute, Inc., Cary, NC) with treatment and period as fixed effects and dog as a random effect. Red blood cell distribution width was highest in dogs fed white sorghum A at 12.9% and lowest in dogs fed white sorghum B at 12.7% (P < 0.05). The anion gap was highest for dogs fed the rice treatment at 24.6 mmol/L and lowest for dogs fed white sorghum A at 22.8 mmol/L (P < 0.05). Cholesterol was higher (P < 0.05) in dogs fed the rice treatment at 246.0 mg/dL compared to the three sorghum varieties (average, 225 mg/dL). Despite the few differences in blood parameters, all were within normal ranges for healthy dogs. There was no difference in plasma ORAC between treatments (P > 0.05). In conclusion, sorghum resulted in normal blood profiles and did not alter plasma antioxidant capacity compared to the rice control when fed to dogs. If antioxidant potential is desired, a concentrated pericarp (bran) extract may be necessary.