Answer:
100% white cow
Explanation:
This question involves a single gene coding for skin color in cattle. The allele for red color (R) is codominant with the allele for white color (r). Hence, the roan cattle (Rr) will possess both red and white coloration.
According to this question, a white bull (rr) is crossed with a white cow (rr). Each parent will produce the "r" gamete, which when used in a punnet square will produce all WHITE COWS i.e 100% white cows. See punnet square attached.
