Connection among carotenoids in maize silage and yolk colour

Abstract

In the feeding trial with 600 laying hens of Isa Brown the effect of ensiled maize grains on colour of yolk and content of beta carotene and xantophylls was studied. At the age of 32 weeks the hens were divided into six groups, each contained 100 animals. The experiment lasted 154 days. Two maize hybrids Raissa and Lotus were compared. In the ration there were 40 % and 60 % of dry matter from the ensiled grains respectively. The supplemental feeding mixture was the same in both cases. Groups on trial rations and one control group on feeding mixture with no added pigment were fed restrictively. In the second control group the laying hens were fed on complete feeding mixture ad libitum. The results were statistically processed by SAS/STAT (SAS Institute Inc., 1989). Rations with 60 % of silage caused significantly darker colour of yolk. The amount of xanthophylls in the silage was significantly related to xantophylls in yolk. The content of xanthophylls in yolk depended on their content in rations. The maize hybrid Raissa affected the darker of yolk colour. Lotus increased the content of beta-carotene in yolk. There were no differences in the content of beta-carotene between the hybrids while Lotus contained significantly less xanthophylls.