Aside from the very, very much needed more kitchens (or a queue in them a la farm story).
I would like to suggest that cows you pay gems for have a chance (or always) drop 2 milk. After all the pigs you pay gems for drop two bacon. Right now a gem cow seems to do very little different from (maybe slightly higher chance of hide?) than a cow bought with coins.
And I agree with the poster above, bunnies are welcome!