Feed rations are calculated mixtures of feed ingredients formulated to meet the nutritional requirements of livestock at specific life stages. A balanced ration provides the correct amounts of energy, protein, Minerals and Supplements, vitamins, and water for maintenance, growth, reproduction, or production. Feed formulation takes into account the animal species, age, weight, production stage, and the nutrient content of available feed ingredients. The process begins with Hay and Forage and forage analysis and adds concentrates to balance the diet.
Energy is the most critical nutritional component and is typically expressed as total digestible nutrients or net energy for maintenance, gain, and lactation. Protein requirements are stated as crude protein, with specific amino acid requirements for monogastric animals such as pigs and poultry. Mineral requirements include calcium, phosphorus, magnesium, potassium, and trace minerals including zinc, copper, and selenium. Vitamin requirements vary by species; ruminants synthesize B vitamins and vitamin K through rumen fermentation.
For ruminants, the ration is typically expressed as a forage-to-concentrate ratio. A dry pregnant cow in mid-gestation requires a maintenance ration of 100 percent good-quality forage with a mineral supplement. A lactating dairy cow producing 30 kilograms of milk daily requires a ration of approximately 50 percent forage and 50 percent concentrate. The Pearson square method is a simple tool for balancing two feed ingredients to achieve a target protein percentage. More complex rations are formulated using least-cost computer programs or consultation with an animal nutritionist.
Forages including pasture, hay, and silage provide the foundation of ruminant diets. Grains such as corn, barley, oats, and wheat provide concentrated energy. Protein supplements include soybean meal (44 to 48 percent protein), cottonseed meal, canola meal, and alfalfa. Byproduct feeds such as distillers Grain Storages, beet pulp, and soybean hulls are economical energy and fiber sources. Commercial premixes supply trace minerals and vitamins.