Hybrids

[Coopscraft]

when breeding a large and small breed, chicken, what determines the size of offspring?

 

[CountryFlock]

Usually offspring are an average of the two parents, size and weight wise.

 

[Amer]

Multiple genes control the size of offspring. Normally it will be an intermediate between the two, but sometimes the mixing of genes between two birds of similar size but different genes creates a strange phenomenon where the offspring are surprisingly larger or smaller than their parents.