If your rabbit isn't gaining weight after making the above changes, try a small amount of plain oats to encourage eating and weight gain. (smallanimalchanel.com)
I tried plain oats in my original recipe trial and it wasn't good. (busybuthealthy.com)
It's a gorgeous blend of oat flakes, wheat bran, oat bran and flaxseed, which makes it a little more hearty and earthy than just plain oats. (twospoons.ca)