Good quality hay can be made from the perennial grasses if they are fertilized properly and mowed while in the boat stage.
The alfalfa weevil has reduced yields of alfalfa in Kentucky to the point where some farmers will be short of hay , Many of these fields have a good stand of grass . Some of the hay shortage can be eased by applying nitrogen fertilizers on these fields.
Corder, George D., "Make Good Hay from Perennial Grasses" (1967). Agronomy Notes. 212.