Characterisation of spray dried hydrolysed chicken liver powder : effects on palatability and digestibility when included as single source of animal protein in dog diets

Abstract

This study aimed to evaluate a commercial hydrolysed chicken liver powder (HCLP) as a single source of animal protein in diets for adult dogs. A characterisation of the HCLP was followed by assessment of diets palatability and in vivo and in vitro digestibility. Two extruded isonitroge- nous diets were produced: control (poultry byproduct þ bovine meat and bone meal) and HCLP. Twenty-two dogs of different breeds were used to test palatability, and twelve Beagle dogs were used to evaluate digestibility. HCLP had high concentrations of lysine, linoleic and arachi- donic acids, and most of peptides with molecular weight <10 kDa. HCLP diet had the highest inclusion of the experimental ingredient based on its chemical composition. Dogs did not show preference among diets (p > .05). Ash and fat intake were higher in dogs fed the control diet, (p < .0001) and (p 1⁄4 .0135), respectively. Crude fibre intake was higher in dogs fed the HCLP diet (p 1⁄4 .0001). Dogs fed the HCLP diet had similar faecal score (p > .05) compared to control diet, although faecal dry matter was reduced (p 1⁄4 .0321) and the daily faecal production was increased (p 1⁄4 .0361). The diets in vitro digestibility did not differ (p > .05). Based on our results, HCLP included up to 26% in diets for adult dogs presented satisfactory results in palatability, digestibility of nutrients and energy, faecal and urinary characteristics. Although dogs fed the HCLP diet produced slightly moist stools, it had no negative impact on faecal score.