This document discusses managing dietary phosphorus in dairy cattle to reduce phosphorus pollution. It notes that phosphorus intake is directly related to phosphorus excretion in manure. A study in Virginia found that reducing dietary phosphorus levels in dairy rations by 5-15% through nutritionist guidance and incentive payments lowered the amount of phosphorus being fed to and excreted by dairy cows on farms. The challenges of reducing phosphorus include the high phosphorus content of common byproducts like distillers grains and needing more information on the availability of organic phosphorus from feed sources.