itch.io

I would suggest a feed effectiveness ranking similar to the following:

1. TMR - 100%
2. Grass (grazed or fresh cut)/ silage / hay + concentrates - 85-90% 
3. Grass (grazed or fresh cut) / hay / silage alone - 75 - 80%
4. Meadow grass (i.e. lower quality pasture, not fertilised or improved) - 60%

Various feed trials / research would indicate that TMR fed cows are higher yielding than those fed grass alone or fed grass + concentrates (even when well managed pasture systems are considered).