Factors affecting egg shell colour in crosses between Australorp and Rhode Island Red chickens

Abstract

The intensity of the brown colour of eggs from reciprocal crosses between Australorp and Rhode Island Red chickens decreased with age of the bird in a non-linear manner. There was no convincing evidence of sex-linked effects on shell colour in these two breeds. No relationship was observed between shell colour and egg number or egg size. Food intake was found to be associated with shell colour; the two crosses were significantly different in their response.