Abstract
Pork-based dog foods are increasing in popularity, but there has been a lack of research conducted on these diets, including information about their digestibility. Therefore, the objective of this experiment was to determine the true nutrient and amino acid (AA) digestibilities of commercial pork-based extruded dog foods using the precision-fed cecectomized rooster assay. Four commercial extruded diets were tested in this study, including three pork formulas (PF1; PF2; PF3) with varying levels of legume content, and a multi-protein formula (MPF), all provided by Champion Petfoods (Alberta, Canada). A precision-fed rooster assay utilizing cecectomized roosters was conducted to determine the true nutrient digestibility and standardized AA digestibilities of the diets tested. All animal procedures were approved by the University of Illinois Institutional Animal Care and Use Committee prior to experimentation. 16 cecectomized roosters (4 roosters/substrate) were randomly assigned to test substrates. After 24h of feed withdrawal, roosters were tube-fed 30g of test substrates. Following crop intubation, excreta (urine and feces) were collected for 48h. Endogenous corrections for AA were made using 5 additional cecectomized roosters. All data were analyzed using the Mixed Models procedure of SAS 9.4. There were no significant differences in true macronutrient digestibilities among diets tested. For most of the indispensable AA, digestibilities were greater than 80%, with some being greater than 90%. For the majority of indispensable and dispensable AA, MPF had higher (P < 0.05) AA digestibilities than the other diets tested. For the majority of indispensable AA, PF1 had the lowest AA digestibilities. In general, the diet containing a mixed protein source had the greatest AA digestibilities, but all diets including those based on pork protein performed well.