Elizabeth L. Geary and colleagues (2023), writing in the Journal of Animal Science, examined how different processing methods affect nutrient digestibility and fecal outcomes in dogs. The study compared five chicken-based diets: extruded kibble (EXT), fresh (FRSH), frozen raw (FRZN), hybrid freeze-dried raw (HFD), and raw freeze-dried (FD).
The trial included ten healthy adult spayed female dogs in a replicated 5×5 Latin square design, with each diet tested for 35 days. Fecal samples were collected to assess apparent total tract digestibility (ATTD), pH, bile acids, and fermentation metabolites.
Key findings included:
• Protein digestibility was highest in frozen raw (FRZN) and freeze-dried raw (FD).
• Fat digestibility was highest in hybrid freeze-dried (HFD) and lowest in extruded (EXT).
• Fecal output was greater in dogs fed extruded and fresh diets compared to raw-based diets.
• Fecal quality was firmer in raw diets (FRZN, FD) than in fresh or extruded diets, which produced looser stools.
• Gut metabolites such as short-chain fatty acids were highest in extruded diets, whereas freeze-dried and frozen raw diets produced fewer.
The study demonstrates that processing type significantly alters digestion and gut outcomes. While raw diets showed superior protein digestibility and firmer stools, extruded diets generated more fermentative activity in the gut. These findings underline the importance of diet format, not just ingredients, in canine nutrition.
Source: Geary, E. L., Swanson, K. S., & Templeman, J. R. (2023). Apparent Total Tract Nutrient Digestibility of Frozen Raw, Freeze-Dried Raw, Fresh, and Extruded Dog Foods and Their Effects on Fecal Characteristics and Metabolites of Adult Dogs. Journal: Journal of Animal Science. Publication Date: 2023-11-06. Authors: Elizabeth L. Geary, Kelly S. Swanson, Joseph R. Templeman.
