Lactating cows naturally have limitations on dry matter intake and always have issues on feed intake. Therefore the digestibility of diets fed to dairy cows are reduced with increased feed intake. (Tyrell and Moe, 1975).
This reduces the energy value of any given diet as the feed intake increases. This is particularly important especially in milk producing cows, where it is uncommon for feed intake to exceed 4 times its maintenance level. The decline rate in digestibility with level of feeding has been proven to be related to digestibility of the diet at the maintenance level (Wagner& Loosli, 1967).
To be profitable from dairy farm operations, it is imperative to maximize the energy intake of dairy cows and minimize the negative energy balance.