Is This Grass Ok To Feed?

There's an abundance of gorgeous spring grass in my lawn at the bottom of the garden, however a large pine tree often drops its cones on the lawn here (not sure what type of pine it is - the cones are long).

As long as I make sure that there's no bits of the tree/cones among the grass am I ok to feed him it from this area? The rest of the lawn is v sparse.

I give my rabbits pine cones as a treat - they love them. I was told that I need to sterilise them first - but that wouldn't happen in the wild - and I don't sterilise hay or grass.

I'd have thought that the grass would be full of goodness for them.

I'm not sure if the frost might have got to it last night? Frosty veg or grass isn't so good for them - and if they've not had grass for ages just give them a small handful for a few days, to let their tummies get used to it again - spring grass is notorious for causing bloat.