Interactions of flavin containing monooxygenase 3 (FMO3) genotype and feeding of choline and rapeseed cake on the trimethylamine (TMA) content in egg yolks of laying hens

Abstract

To evaluate the relationship between the FMO3 genotype and dietary trimethylamine (TMA) precursors on TMA-N content in eggs, laying hens were fed with choline (500 and 4000 mg/kg diet) and, in a later trial, with rapeseed cake (0, 100 and 300 g/kg diet). Hens were genotyped for non-synonymous A/T polymorphism at position nt1034 of the cDNA of the FMO3 gene, which is associated with elevated TMA-levels in egg yolks. Genotypes were equally distributed among the experimental diets. TMA was extracted from yolks and measured as TMA-N by a colorimetric method. As expected, hens of the TT-genotype had high amounts of TMA-N in egg yolks when fed either 4000 mg choline/kg diet or the rapeseed cake diet, while hens of the AA-genotype showed low levels of TMA-N. Heterozygous AT-hens had a slightly increased level of TMA-N when fed with 4000 mg choline/kg diet but not with the rapeseed cake feed. Rapeseed cake can be fed to AA and AT hens without leading to fishy tainted eggs.

Keywords:

• laying hens
• trimethylamine
• genotypes
• choline
• sinapine
• egg quality

Acknowledgements

The assistance of the co-workers of the Institute of Animal Welfare and Animal Husbandry in Celle is gratefully acknowledged. We thank Mrs A. Weigend for technical help in genotyping and TMA analysis. We thank Dr A. Baumert and his colleagues from the Institut für Pflanzenbiochemie Halle for sinapine analysis in rapeseed cake and diets. And also for Dr A. Gurgel and his colleagues from the Landesforschungsanstalt für Landwirtschaft und Fischerei Mecklenburg-Vorpommern, who analysed the glucosinolate content in rapeseed cake and diets. The experiment was supported financially by the “Gesellschaft der Förderer und Freunde der Geflügel- und Kleintierforschung e.V.”, which is gratefully acknowledged.