The experiment was carried out to evaluate the increasing levels of anatto extract (AE) oil in sorghum-based diets as the main energy source. A total of 280 laying hens in the second production cycle, 140 Lohmann Selected Leghorn (LSL) and 140 Isa Brown (IB), was allotted to a density two birds/pen and full fed seven diets. The treatments consisted of a positive control corn based diet, as principal energy source, and a basal sorghum diet, as principal energy source, supplemented with 0.0, 0.10, 0.15, 0.30, 0.45, and 0.60% of AE. A completely randomized design in a 7 x 2 factorial arrangement (treatment and line), with five replicates of four birds, was used. The egg yolk colour was linearly improved by addition of AE to the sorghum-based diets. The brown-egg layers presented better egg yolk colour than the white-egg layers. The addition of 0.1% AE to the sorghum-based diets produced similar egg yolk colour as the corn based diets.
anatto oil extract; egg yolk colour; natural colorant
