Dietary bioactive peptides (BP) may have positive health effects, but are poorly tested in cats. Our primary objective was to determine the apparent total tract digestibility of BP-containing kibble diets and assess how fecal characteristics, metabolites, and microbiota were affected in adult cats. Our secondary objective was to test whether BP could impact blood oxidative stress markers and cytokines following transport stress. Adult cats were used in a replicated 4 × 4 Latin square design to test four extruded kibble diets containing different BP concentrations. After diet adaptation, fecal and blood samples were collected and transport stress testing was done in each experimental period. All cats remained healthy and serum metabolites remained within reference ranges. Cats fed one of the BP diets had higher dry matter and organic matter digestibilities and tended to have higher protein and energy digestibilities. Fecal characteristics, metabolites, and microbiota diversity measures were not different, but the relative abundances of eight bacterial genera differed or tended to differ across treatments. Treatments did not alter oxidative stress markers after transport stress. Our data suggest that BP inclusion may increase nutrient digestibility and modify fecal microbiota. Further testing is required to determine whether BP provides additional benefits to cats.

Read the full article in the Journal of Animal Science.