After 8 years of eating hay all day - they now won't touch it!!

So, my 2 buns (1.5 kg and 1.6 kg respectively) have eaten hay all their lives. Somewhere between 3 and 4 large handfuls a day between them. Therefore, they've always had perfect teeth until they got a bit older (they're 8 yrs) and have had some very mild dental issues - Bramble in particular has had a couple of spurs dealt with at the vets.

However, since we moved house they have more access to grass and with me now working from home daily due to the pandemic, they're on grass from 9 am until 6 pm.

Which is great, they love it! But now they won't touch hay in their hutch. I've tried different varieties and put their favourite 'treat' hay in there (oaty harvest) and they've not having it.

I guess my question is, what's the risk to their teeth if they're not eating any hay? I always thought that they needed hay as well as grass as it's more abrasive on the teeth.

Thanks

Ours eat a LOT less hay when there's grass available. So, if they've been out on the lawn, which isn't ALL grass (there's a lot of moss and violets :S) they might eat a bit of hay once they're locked back in. Or sometimes, the girls moreso than Lopsy, they come back inside to specificially eat hay (Chibbs did this a fair amount a couple of weeks ago). I haven't had to top up the hay rack in the playhouse at all for two and a half weeks and they haven't had access to grass all that time, it's just taken them that long to get through the same amount as they'd eat in half a week in midwinter! Forage has increased too, but not significantly because we've been lazy (working from home = not passing the good places to and from work :lol.

I think grass is the same but because it's 'wetter' they might need more, and might eat more than hay? It's to do with silicates IIRC. Certainly I've never had a dental issue with mine when they're on 90% grass, and Aboleth's teeth were described as 'all over the place' by our vet Both her and Lopsy had/have tiny spurs that don't worry them (vet says he sees rabbits who tolerate them better and worse) and I suspect Chibbs' teeth aren't great being a lionhead, but she hasn't seen our vet yet so can't confirm. Certainly no issues though.

Grass is better than hay so if they eat a lot of grass they won't want/need as much hay!

My bunnies much prefer grass to hay. There will be no detriment to their teeth, nor their digestion. I don't think I would be at all concerned and come next Winter when there is no fresh grass, they will probably return to eating hay.

Thanks guys. It just really took me by surprise as they have always been big into their hay. They're loving the grass and these long sunny evenings we're having