Factors affecting dry matter intake and its prediction for Holstein cows

Many factors affects dry matter intake (DMI). Individual theories based on physical fill of the reticulorumen, metabolic-feedback factors, or oxygen consumption have been proposed to determine and predict DMI (NRC, 2001). Prediction of DMI is fundamentally important in nutrition because it establishes the amount of nutrients available to an animal for health and production. Actual or accurately estimated DMI is important for the formulation of diets to prevent underfeeding or overfeeding of nutrients and to promote efficient nutrient use. Underfeeding of nutrients restricts production and can affect the health of an animal. Overfeeding of nutrients increases feed costs, can results in excessive excretion of nutrients into the environment, and at excessively high amounts may be toxic or cause adverse health effects. Several DMI prediction equations have been developed for use in the field, but only a few have been given in this paper