Abstract
1.âThe effects of various sources of natural carotenoids (Px alfalfa concentrate, tomato powder and marigold extract) as feed additives in quail diets on egg yolk pigmentation and carotenoid composition were investigated.
2.âAdult Japanese quail were fed one of 5 different diets for 23âd: three diets each contained Px alfalfa concentrate (PX) or tomato powder (TP) or marigold extract (MG), one diet contained marigold extract and tomato powder (MGâ+âTP) and a control diet (wheat/barley based) was low in carotenoid. All products were added at a rate of 2%, apart from marigold extract which was added at a rate of 0·2%.
3.âVisual assessment of yolk colour (Roche colour fan) showed a stabilised yolk colour of 1·6, 7·7, 8·5, 8·8 and 10·6 for the control, PX, TP, MG and MGâ+âTP treatments, respectively.
4.âThe total carotenoid concentration of the egg yolks were 2·2, 22·4, 4·1, 39·0 and 37·7âµg/g for the experimental groups fed the following diets: control, PX, TP, MG and MGâ+âTP, respectively. Deposition of retinol, α-tocopherol and γ-tocopherol in the egg yolk was unaffected by treatments.
5.âLutein was shown to be the major carotenoid in the egg yolk, comprising 1·65, 17·97, 2·03, 31·14 and 28·57âµg/g in control, PX, TP, MG and MGâ+âTP, respectively. Inclusion of TP in the quail diet resulted in lycopene transfer to the egg.
6.âIt was concluded that, in comparison with the control group, there was an increase in the yolk concentrations of lutein, zeaxanthin, lycopene and β-carotene in eggs produced by female quail fed diets supplemented with natural carotenoids.
Acknowledgements
The authors gratefully acknowledge The Scientific and Technical Research Council of Turkey (TUBİTAK) for a NATO Science Fellowship for Filiz Karadas and the SAC receives financial support from SEERAD.