2.2. Experimental diets

The experimental diets were formulated to meet the nutritional requirements of adult horses at maintenance according to the NRC (2007) recommendations. Free access to Tifton 85 hay (Cynodon spp.) and a commercial pelleted concentrate, in the quantities recommended for adult horses at maintenance (NutriEqui PMSE^®15.6), were offered daily, and water and mineral mix were offered ad libitum (Guabiphos Centauro 80^®, Guabi Animal Nutrition) (Tables 1, 2).

Chemical composition of diet components (based on dry matter, DM)

1 NutriEqui PMSE 15.6, Guabi^® Nutrição Animal. 2 NDF denotes neutral detergent fiber. 3 ADF denotes acid detergent fiber. 4 Digestible energy (Mcal/kg) was calculated using the equation proposed by NRC (2007): DEconcentrate (Mcal/kg) = 4.07 – 0.055 × (ADF %), and DEroughage (Mcal/kg) = 4.22-0.11 × (ADF %) + 0.0332 × (CP %) + 0.0012 × (ADF %2). 5 Nonstructural carbohydrate (%) was calculated using the equation proposed by Hoffman (2001).

Chemical composition of the total diets composed of commercial concentrate1, forage palm bran and Tifton 85 hay (Cynodon spp.).

1 NutriEqui PMSE 15.6, Guabi^® Nutrição Animal. 2 NDF denotes neutral detergent fiber. 3 ADF denotes acid detergent fiber. 4 Digestible energy (Mcal/kg) was calculated using the equation proposed by NRC (2007): = 4.07 - 0.055 × (ADF %), calculated values (NRC, 2007). 5 Nonstructural carbohydrate (%) was calculated using the equation proposed by Hoffman (2001).

For the preference test and digestibility test, four treatments were applied:

Treatment 1 (control) – no FPB;

Treatment 2 – inclusion of 5 % (50 g/kg) FPB as a substitute for commercial concentrate;

Treatment 3 – inclusion of 10 % (100 g/kg) FPB as a substitute for commercial concentrate;

Treatment 4 – inclusion of 15 % (150 g/kg) FPB as a substitute for commercial concentrate.