Ok, I have additional information and questions.

Firstly I have managed to find a couple of references to too much protein being bad for adult rabbits: “while protein is an important part of their diet, too much can overwork their kidneys, so it is important to ensure you are providing the right amount.” and “During this time, excess protein can cause a rabbit’s kidneys to overwork to filter out waste products caused by protein breakdown in the body.” Which basically rules out the Teff hay as a means of weight gain. Chatting to my husband he mentioned that in people if you’re taking things like protein shakes and not using the protein, your body filters it out anyway and it’s not even used. Which explains why it would be bad for a rabbit’s kidneys filtering out waste products.

My next thought is, what can I do to increase Luna’s weight? She hovers around 1.8kg when ideally she should be around 2.2kg. Currently she’s getting Oxbow Essential pellets (I was feeding Oxbow Garden Select but I couldn’t get them when I needed them). Just looking online I couldn’t actually find an energy rating kilojoules/calorie value for any rabbit pellets online. But I did notice that the Oxbow is actually very low in fat at 2.5% but the Burgess Excel with mint has 4% fat. So I’m wondering if that’s a better option for her. That being said, would it even make a difference to her with how little pellets she eats (2-3 teaspoons a day)?

I have been giving some oats, but only a pinch so probably not enough, I didn’t want to overdo it, maybe max 1 tablespoon a day? I think I’m going to have to separate her from Apollo sometimes so I can give her more.