RESUMO
This study evaluated the effects of inclusion of Yucca schidigera extract (YSE) in two diets with different levels of crude protein (CP) for dogs on facal odour, nutrient digestibility, ammonia concentration in feces and hematological and serum biochemical profiles. Twenty adults Beagles were used, distributed in a randomized block design in a 2 × 4 factorial design (two diets, 25% and 34% CP, and four YSE levels: 0, 250, 500 and 750 mg/kg) with five replicates, obtained during two experimental periods. The fecal odour reduced (P < 0.05) when 500 mg/kg of YSE was used in diets with higher CP. The inclusion of YSE reduced (P < 0.05) fecal ammonia, and the inclusion of 250 and 500 mg/kg YSE reduced intestinal gas. The inclusion of 750 mg/kg YSE increased the mean corpuscular hemoglobin (MCH), alanine aminotransferase (ALT) activity and tended to increase the serum cholesterol concentration, regardless of the protein level of the diets. There was no effect on the digestibility of nutrients, fecal consistency, nitrogen balance and thickness of the intestinal wall. The inclusion of 500 mg/kg YSE is effective in reducing fecal odour in dogs receiving diets with 34% of CP. Regardless of the protein content, YSE reduces fecal ammonia, but may cause adverse effects if included at higher doses.