Tainting eggs of brown hens - occurrence in spite of an 'uncritical' diet composition.

Fishy or unpleasant egg taint occurred in a high frequency (10 %) in a herd of brown layers. The hens were fed a commercial standard diet, that did no t contain the known critical ingredients as fish meal or rape seed and had an average choline concentration. Sensory tests of the drinking water did n ot reveal any abnormalities. In a subsequent feeding trial an oral antibiot ic treatment with neomycin alone had no positive effects while neomycin and tetracycline reduced egg taint significantly until it became almost normal . Microbial activities in the GI tract were therefore obviously responsible for the egg taint.