Here's a quick note on a neat paper.
Grazers have a tough choice sometime.
Eat grass. It doesn't taste bad, but often doesn't have high protein concentrations.
Eat forbs. They often have higher protein concentrations, but taste bad.
And they taste bad because they have compounds that reduce the digestibility of food or make them ill.
Many grazers try a balance. Eat forbs, but not enough to make them sick.
What happens when you supplement grazers with protein? Is there any reason to still eat forbs?
Supplement cattle in Kenya with protein (during the dry period) and their forb intake drops by 76%.
Many grassland managers manage for grass, but forbs can provide an important part of their diet. It's hard to manage for diversity, but if we can figure out how to do it well, there are economic and conservation benefits.
Odadi, W. O., M. K. Karachi, S. A. Abdulrazak, and T. P. Young. 2012. Protein supplementation reduces non-grass foraging by a primary grazer. Ecological Applications 23:455-463.