if I have a small young male, I'll breed him to 1 or 2 females. but before I got the ultrasound, I like to get a good lock once a month to every female that a good breeding size male was breeding too, and still giving him the time off between females. I have a new breeding male this year, he's around the 800 gram mark. he's breeding and also eating. so he can be breed to more with him being on feed. just my way of doing things with good results.