Many of you answered, and some of you said PROTEIN.
However, it was those of you who answered FIBER that are correct!
This post is going to be centered on the importance of fiber and protein, and which one is more important than the other.
Pellets usually have 20-23% fiber. In my opinion, any fiber content lower than that is a no-no. Fiber is also found in hay, which is what makes hay so important.
Without fiber in their diet, rabbits' digestive systems would come to a standstill; they wouldn't poop, or eat, because they would always feel full. They would have a blockage in their digestive system; this is commonly known as G.I stasis, which stands for gastro-intestinal stasis. It's when the rabbit's digestive system comes to a complete stop.
In pellets, protein is usually 14-18% protein. I highly discourage anyone from buying a feed with a protein content less than 16%, which is what my rabbits are fed. Protein helps the rabbit grow and gain essential fat and keep its proper weight. Energetic breeds, like the Holland Lop, need a high protein content to support their high energy.
Baby bunnies, and lactating does, need high protein to support the babies' rapid growth and to provide the mother with essential nutrients and enhanced milk production. Nursing does with a low protein diet will lose weight and not make as much milk.
In short, I believe that fiber is the most essential, yet protein is quite close. Both are absolutely necessary in the diet. Rabbits can't survive without either. But people usually overlook fiber and its importance.
What are your thoughts?