How much crude protein and energy is required for a dairy milking cow?
First Question is how much a cow can eat daily. You need to balance your ration according to that. What it eats is directly proportional to its weight. Then next question is how much milk is expected of the cow and at what butter fat. Also keep in mind the ratio of forages to concentrate ratio. CP and Energy will depend on the for ages part remaining has to be filled by the concentrate part. At one point qunatity of concentrate has to be restricted because of how much a cow can eat plus the ratio on DM basis.