If you're really good you could breed a male to 10 females. A lot of that would depend on luck with when the girls are nearing ovulation. Some people know how to tell when the female is close to ovulation so well they pair once and get the job done. If you're asking this question, you're probably not at a place where it's safe to breed a male to that many females.

PLEASE give your males time off though. Breeding takes a huge amount of energy and you'll notice the toll it takes if you overbreed. Males are known to die if you do overbreed due to the stress and energy required. Monitor his weight and know when to give a break and when to call it quits for the season.