Phosphorus is the second most expensive nutrient added to dairy rations. Unfortunately, that extra phosphorus is oftentimes not needed, says David Beede, dairy nutritionist at MichiganStateUniversity.

When it comes to determining the true phosphorus content of feeds, use wet chemistry lab analysis instead of NIR, advises Beede. When an NIR test is used to determine the phosphorus content of feeds, research shows that the results will be lower than the actual P content because of the unusual way phosphorus binds with the plant matrix. And, when you feed cows more phosphorus than they need, the end result is more phosphorus in manure and urine for you to properly dispose.