Evaluation of dried apple pomace on digestibility and palatability of diets for cats

Abstract

The objective of this study was to evaluate increasing levels of dried apple pomace on cat diets and its effects on the apparent total tract digestibility (ATTD) of nutrients and diet metabolizable energy (ME) and palatability. Fecal characteristics of cats were also evaluated. Four experimental diets were produced to contain 0, 30, 60, and 90 g kg−1 of dried apple pomace. Two experiments were carried out. In experiment 1, the diets were offered to twelve adult cats distributed in a completely randomized block design (n = 6). Two evaluation periods (blocks) of 11 days were used to analyze diet digestibility and fecal characteristics. In experiment 2, the palatability of diets containing 0 (control) vs. 90 g kg−1 of dried apple pomace was compared using 20 adult cats on two consecutive days (n = 40). Increasing dietary dried apple pomace levels (0-90 g kg−1) linearly reduced the ATTD of crude protein (834.0-798.0 g kg−1 of dry matter) and ME (4290.1-4161.0 kcal). There was a quadratic effect of the increasing dried apple pomace levels on the ATTD of the other nutrients, as well as on fecal dry matter (fDM) content and output. The dietary inclusion of 90 g kg−1 of dried apple pomace promoted a greater intake ratio (0.61) in relation to the control diet. The inclusion of up to 90 g kg−1 of dried apple pomace reduces diet digestibility, ME, and fDM of cats. However, it improves diet palatability. These results indicate that the dried apple pomace is a palatable fibrous component and its inclusion can be used to reduce the energy content of cat foods