Hi all! I started breeding rabbits earlier this year, I have a New Zealand blue buck (Mr Blue), a Californian doe (Sesame) and a Harlequin doe (Poppy). I’ve already had a few litters this year with both females, but recently I’ve tried pairing Poppy to Mr Blue and he hasn’t been doing the “falling over” part when mating with her, which I understand to be how you tell the male has succeeded. He just humps her for a bit and nothing happens :/ They are both receptive to mating and healthy, so I’m not sure why this is happening. He had a successful litter with her that was born a couple weeks ago, so idk what is happening this time around. It is currently early winter where I live and around 25-40 degrees on any given day. Mr Blue is around 2 years old and Poppy was born in may 2019 so is a little less that 2. I bought some vitamin drops to give to the male to see if that helps, but does anyone have any ideas what could be the problem? Thanks!