Anyone who feeds just grain and no pellets.. Should have Selenium yeast in there grains.. THis will help rabbits to keep there weight up ... Some rabbits dont eat all of there night poops and they dont get all they really need. THis will help allot... If you are feeding pellets.. This dosnt not apply to you..
http://en.wikipedia.org/wiki/Selenium_yeast
http://en.wikipedia.org/wiki/Selenium_yeast