Using quails as a model for poultry production was already evaluated by Wilson et al (1961), and by Nelson (1966) specifically for egg yolk color. More recent references of quails as a model for chickens’ egg yolk color have not been found. This work updates the one of Nelson with present birds’ strains and pigments to predict laying hens’ egg yolk color from quails’ egg yolk color.
Materials and methods
The studies were conducted on 54 cages with 8 quails and 9 cages/treatment (Tr); and on 48 cages with 3 hens and 8 cages/Tr; experimental unit was 1 cage in all cases. Basal diets were wheat-based without xanthophylls addition, that met birds’ requirements for each species. A period of xanthophyll depletion was implemented, followed by the experimental period when xanthophylls were added to the basal diets. Studies had a Randomized Complete Block Design with 1 wk previous laying rate as blocking effect. There was a total of 6 Tr, the same for both studies, that arose from the addition of canthaxanthin (CTX) combined with apo-ester (APO) or ColorTek Yellow® (NOVUS, CTY) at different levels (ppm of total xanthophylls) to cover commercial pigments used and egg yolk colors targets as follows: a) CTX1.5+APO2.5; b) CTX1.5+CTY3.1; c) CTX1.5+CTY3.8; d) CTX3.0+APO3.0; e) CTX3.0+CTY3.8; f) CTX3.0+CTY4.5. Egg yolk color was assessed by a Minolta CR300 colorimeter and DSM Yolk Color Fan (YCF) on >1000 eggs from each study (from 176 to 241 eggs/Tr); proc means, corr and glm of SAS 9.4 were used.
Both YCF and ratio redness/yellowness (ab, Galobart et al, 2004) from quails’ eggs yolk were well correlated (R2≥0.9, P<0.01) with the values in chickens’ eggs yolk, though quails had lower values and higher variability.
Laying hens’ eggs YCF could be predicted using quails’ eggs as: YCFlaying hens=10.1+12.3×abquails (CV=2.3%)