[Animal nutrition for veterinarians--recent cases: odor variations in eggs from brown hens and also possibly in...

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 not contain the known critical ingredients as fish meal or rape seed and had an average choline concentration. Sensory tests of the drinking water did not reveal any abnormalities. In a subsequent feeding trial an oral antibiotic 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.