Metabolisable energy value and digestibility of fat and fatty acids in linseed determined with growing broiler chickens.

1. In the first experiment, the AMEN of linseed was evaluated at rates of 40, 80, 160 and 240 g/kg in a basal diet with broiler chickens aged 28 d using the total collection method. 2. Increasing the concentration of linseed decreased the AMEN of diet, from 11.78 to 8.75 MJ/kg DM, and AMEN of linseed, from 16.64 to -2.96 MJ/kg DM. The negative values clearly indicated that linseed interacted with the other dietary ingredients and impaired their energy utilisation. 3. In the second experiment, a semipurified diet with graded addition of linseed (80, 120, 160 and 240 g/kg DM) was evaluated for crude fat and fatty acid apparent digestibilities. The coefficients decreased from 0.602 to 0.359 for crude fat and from 0.661 to 0.352 for individual fatty acids as the level of linseed increased. 4. In both experiments, a quadratic regression model explained the relationship between data better than the linear model. 5. The presence of mucilage and other antinutritional factors in linseed might explain the results obtained in this study.