When nutritionists balance rations for dairy cattle, they
assume that the cow will receive a certain amount of dry
matter from a particular feed. As the feed becomes wetter,
more of the feed needs to be included in the TMR in
order to provide the same amount of dry matter to the
cows and keep nutrients in their correct proportions. The
reverse is also true: as feeds become drier, less of the forage
or feed needs to be included. Nutritionists often