Effects of natural oxycarotenoids on the immune function of Japanese quails

Abstract

Adult Japanese quail layers were immunized by a combination of goat red blood cells and bovine serum albumin (100 µg/animal/ i.m.). The control group (C) was fed with commercial layer food, the other group (X) with the same food but supplemented with a mixture of natural xanthophylls (1000 ppm Capsantal EBS 40 NT: extraction of Tagetes erecta; active substances: 40 g/kg yellow xanthophyll: 0.8 % ß-carotene, 1.5 % cryptoxanthin, 82.0 % trans-lutein, 4.0 % trans-zeaxanthin, 11.7 % other carotenoids). Blood and egg samples were collected in two weeks intervals for six weeks. The samples were analyzed for retinoid and carotenoid spectrum by HPLC and for the avian immunoglobulin-Y (IgY) titres by ELISA and haemagglutination inhibition test (HAI). The colours of egg yolk and skin were characterized by CIELAB values (MicromatchsTM Sheen Ltd). The concentrations of oxycarotenoids were increased continuously in the blood of group X. There were no differences between the retinoid concentrations of blood. The yolk colour intensity increased in the 2nd w. in xanthophyll fed birds and the average colouration was higher (p<0.05) throughout the experiment. The skin CIELAB values were as follows: control group L*: 65.8; a*: 4.1; b*: 26; and in the xanthophyll treated group L*: 59.3; a*:7.8; b*: 41.7 respectively. The differences were significant (p<0.05) in the case of b* values. The blood IgY and HAI titres were raised in both the groups and the values were higher for xanthophyll supplemented birds. Recent studies on the role of natural oxycarotenoids have demonstrated that beside the colouration of egg yolk and skin they can enhance the immune function too in Japanese quail.