In cattle, the gene pair for red (RR) or white (WW) coat color shows an absence of dominance. Heterozygotes (RW) have a roan coat. Outline a breeding procedure to establish apure breeding herd of red cattle from a roan bull and white cow.

A cattle breed wants to establish a pure-breeding herd of roan cattle. What could you tell him about his chances for success in such a venture?

A farmer has three groups of cows: white ones int eh clover patch, red ones in the alfalfa field, and roa in the corn field. He has a roan bull named Ferdinand who services the cows in all three fiels. What color calves should he expect in each field?

Ferdinand dies from a bee sting and the farmer decides to make his herd exclusively roan coat in memory of his beloved bull. He sells all the red and white cows, and vows to sell any red or white calvesborn subsequently. What color bull should be bought to replace Ferdinand if he wants to sell as many calves as possible?

2 answers

Why would you honor a dead bull? Getz a life...
His chances of success are zero to none. Roan is heterozygous. That means you cannot have a pure breeding stock. The white cattle will produce 50% white and 50% roan. The red cattle will produce 50% red and 50% roan. The roan cattle will produce 25% white, 50% roan and 25% red. If he wants to sell as many cattle as possible, he should cross a white with a white or a red with a red.