Animal Methods for Evaluating Forage Quality

Fundamentally, forage quality is the ability of forages to support maintenance and production functions in the animals to which they are fed. Both laboratory and animal methods have been developed to predict nutritive value or provide insight into the potential of a forage to support maintenance and or productive functions. Milk yield is a more sensitive indicator of the nutritional value of the diet than is live weight gain over relatively short time periods. Considering forage quality as the ability of forage to provide for animals' needs, voluntary forage intake is paramount because of both its direct relationship with nutrient supply and its indirect relationship with nutrient concentrations. The efficiency of utilization of dietary nitrogen is an important consideration for optimizing the efficiency of ruminant production. Concentrations of nutrients in body fluids (e.g. milk, blood, urine) commonly reflect differences in dietary nutrient concentrations.