HENS EGG - GENETICS OF TAINTS IN EGGS FROM HENS FED ON RAPESEED MEAL

Fishy taints in eggs from hens fed rapeseed meal, reported to occur in brown-shelled eggs of some hens with Rhode Island Red ancestry, occur also in white-shelled eggs of some hens of a strain of Brown Leghorns. Genetic tests have demonstrated that tainting in these circumstances is conditional on the presence in the hen, in the heterozygous or homozygous state, of an autosomal semi-dominant mutant gene that has variable expression, depending on environmental factors (including the rate of ingestion of rapeseed meal). No simple test for the presence of this gene, applicable to either sex, can be anticipated at present.