Effect of oat hulls on performance, gut capacity and feed passage time in broiler chickens

1. Two experiments were conducted to study effects of oat hulls and their i nteraction with soluble fibre in broiler chickens. 2. In experiment 1, wheat or naked oats based diets with or without NSP-deg rading enzymes were mixed with 0, 40 or 100 g/kg oat hulls which replaced a maize starch/soy isolate mixture, and the diets were fed to broiler chicke ns from 7-21 d of age. 3. Production results, AME(II) determined between 14 and 16 d of age, and i leal digestibility indicated no negative effect of oat hulls on nutrient di gestibility or weight gain. 4. Feed consumption increased significantly when oat hulls were included in the diet and relative gut weight increased correspondingly (P<0.05). 5. No interaction effects were found between soluble and insoluble fibres, except for a possible effect on starch digestibility in wheat diets. 6. In experiment 2, mash diets were fed unsupplemented, or were supplemente d with coarsely or finely ground oat hulls which replaced a maize starch/so y isolate mixture. 7. Faecal titanium dioxide excreted between 1 and 48 h after feeding of a g elatin capsule containing titanium dioxide, was used to calculate feed pass age time. 8. There was a tendency (P=0.08) for faster feed passage with inclusion of coarsely ground oat hulls, but no effect of finely ground oat hulls was fou nd.