: If they are similiar to angus, close to 1 yr - plus or minus. We have had bulls that qualify as acceptable potential breeders (BSE - Breeding Soundness exam, from vet) at 11 months (have not tested them younger). The best way to determine if he is physically mature is a BSE. The vet will examine the semen and check for immaturities and abnormalities. In our area they cost around $40 and it includes vaccinations and degrubbing. (A standard recommendation is not turning them out with cows until they are 14 months.) <p>: On another note, these "rookies" can require a little special attention (depends on your pastures/feed etc). You will want to make sure your young bull maintains his condition so that he can continue healthy sperm production. You may wish to limit the number of cows he needs to breed (20-25, or less). Some young bulls have no problem with more, but may look rough at the end of breeding season and require some special care.<br>: So you may wish to keep this in mind as well. Best wishes.<p>: : I have a Beefmaster bull calf that is 9 mos. old now. I would like to use him as a breeder bull. How old do they begin breeding?<p>