It can be done but the issue is if you already have a shy / not ready / not experienced male putting a mature well established male could actually have the opposite effect of what you are trying to accomplish making it worse for that male same goes for male combat.
I prefer using sperm plugs and shed, I do 1.2 ratio along with a few other tricks, and if the male is still a no go than he was just not ready for that season, I have a male with this problem right now too which given his age and weight surprises me but it is what it is.
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