In cattle, polled (absence of horns) is dominant over horned and roan is the result of the heterozygous condition of the genes for red and white coat color. (Neither red nor white is dominant so in the heterozygote, both are expressed, e.g. half of the hairs on the coat are white, and half are red.) Assume both traits are on separate pairs of autosomes.

What proportion of the offspring of a roan, heterozygous polled bull and a roan, horned cow would be expected to be roan and horned?