Nutritional value and fatty acid profile of niger (Guizotia abyssinica) plant during its growth cycle.

The nutritional value and fatty acid profile of the Guizotia abyssinica plant harvested for forage at seven growth stages were determined. Generally, growth stage resulted in an increase in neutral detergent fibre (NDF), acid detergent fibre, lignin, and indigestible NDF and a decrease in protein content, in vitro true digestibility and NDF digestibility. Among the main fatty acids (FA) in the plant during growth, ?-linolenic acid (C18:3 n-3) and linoleic acid (C18:2 n-6) were the most abundant (from 440 to 548 and from 154 to 195 g/kg of total FA, respectively). Some minor FAs showed no differences in their content during growth. The whole plant was characterised by a high proportion of polyunsaturated fatty acids, which made up between 696 and 764 g/kg of total FA, and a low proportion of saturated fatty acids. Niger is a forage plant with a good nutritional value and an interesting FA profile and should be harvested no later than the shooting stage of growth to ensure that the forage has high nutritive value and maintains a moderately high nutrient digestibility.