What age range is men most fertile?
15-25, same as women. In the later 20s and early 30s male fertility starts to decline some, and then takes a sharp hit around age 40. Men still produce sperm after 40 obviously since there's no male equivalent to menopause, but the reduction in sperm count and quality may make it more difficult for a man to successfully father a healthy child.
Anything shortly after puberty (so 15 or 16) until around the age of 35 to 39. After the age of 40 - men can still father a child. HOWEVER their sperm quality and quantity is not as good as it once was and the risk of an older man fathering a child with birth defects increases. Men can father children well into their senior years if they have no other health issues that causes impotence. There is just some risk that the child might have a birth defect.
pit bulls bite
thats highly dependent on how healthy they are and how well they take care of themselves, but i'd say about 15 all the way to 60 lol ...