Use of distillers dried grains with solubles (DDGS), with and without xylanase, in dog food

•The inclusion of 180 g/kg (as fed) of DDGS reduces digestibility of nutrients and energy of diets.•The inclusion of 180 g/kg of DDGS reduces faecal dry matter and pH of dogs.•Xylanase supplementation increases the digestibility of protein of diets containing DDGS.•The inclusion of 180 g/kg of DDGS increases the palatability of the diets.

The effects of different levels of inclusion of distillers dried grains with solubles (DDGS) with and without the addition of xylanase in extruded diets for dogs on total tract apparent macronutrient digestibility, faecal characteristics and palatability were evaluated in two experiments. In the first experiment, the coefficients of total tract apparent digestibility (CTTAD) and faecal characteristics were measured in eight adult Beagle dogs according to a 8 × 8 Latin square design. The following diets were evaluated: 0, 60, 120 and 180 g/kg of DDGS (as fed) with and without added xylanase. In the second experiment, the palatability of the diets was evaluated in separate tests to make three pair-wise comparisons: 0 vs 60 g/kg of DDGS, 0 vs 180 g/kg of DDGS and 180 g/kg of DDGS without enzyme vs 180 g/kg of DDGS with enzyme. Increasing the level of DDGS linearly reduced the CTTAD ether extract after acid hydrolysis (EEAH), gross energy (GE) and estimated metabolizable energy (ME). However, the CTTAD dry matter (DM), crude protein (CP) and organic matter (OM) indicated an increase in diet digestibility after xylanase supplementation (P < 0.05). The DDGS CTTAD CP, EE, and DM, which were estimated from regression analyses, were 0.76, 0.63, and 0.59, respectively. Regarding faecal characteristics, no differences were observed for ammonia and faecal score. However, pH decreased as the dietary inclusion of DDGS increased (P < 0.05). The dietary inclusion of 180 g/kg (as fed) of DDGS improves palatability. Results indicated that the addition of DDGS reduces diet digestibility, however this effect can be attenuated by dietary xylanase supplementation.