Thus, overfeeding or underfeeding of protein and minerals can be common. Diets should be formulated by certified animal nutritionists. Cows should be evaluated for their body condition routinely so that the proper energy level of the diet can be determined. Producers who do not routinely have diets formulated by qualified professionals should be advised to do so. Depending upon the life cycle stage, the roughage to concentrate levels can vary tremendously.
Most nitrogen consumed by cattle is a part of the protein the animal consumes.
When cows consume excess protein, an increased amount of N is excreted in the urine as urea. Small amounts of urea can also be diffused into the milk. The concentration of urea in milk is proportional to the amount of N excreted in urine for cows of a given body weight. It is recommended that MUN be routinely analyzed to help producers determine if too much or too little protein is being fed. Previous target recommendations for MUN were higher, but DHIA labs that analyze milk have since improved their methodology for measuring MUN, and reduced MUN values are now being reported.