Hay is Important Published October 10, 2013 at 1018 × 1018 in PSA’s ← Previous Next → Make sure you always have hay out for your bunnies! Its the most important part of their diet. Adult rabbits need fresh timothy hay, and alfalfa hay is good for growing buns up to 6 months of age, but is too high in calcium and fats for adult buns. Like this:Like Loading...