When should I supplement my pasture-grazed livestock?

Answer: The nutritional concern for ruminants centers around energy (i.e., carbohydrates), protein, minerals, vitamins, and water. Energy (carbohydrates) is responsible for maintenance and growth functions of the animal, and for the generation of heat. Protein grows tissue and performs other vital functions. Other nutrients and minerals such as vitamins A and E, calcium, phosphorus, and selenium can be fed “free choice” as a mineral supplement.Cattle, sheep, and goats–by nature, grazing and browsing animals–grow and reproduce well on pasture alone. However, an intensive and industrial agricultural production philosophy has dictated that crops and animals should be raised faster, larger, and more consistently than a pasture system can deliver. Thus, confinement systems with delivered forages and concentrated feeds have been the norm since the 1950s. Raising animals on grass is slower than raising animals on grain. However, a pasture-based livestock producer will, with careful planning, realize cost savings and subsequent profitability through the efficiency of relying on the natural systems of nutrient cycling, biological pest controls, and perennial pasture productivity.The major operational expense confronting the livestock industry in most parts of the United States is for supplemental feed. In temperate regions of the country that experience adequate rainfall and a lengthy grazing season, supplementation on green, growing, vegetative, well-managed pastures should not be necessary. However, young and lactating stock require more energy and protein than mature, non-lactating animals.Supplementing energy is helpful on vegetative, well-managed pastures for more efficient utilization of forage protein (for high-producing animals). Supplementing with protein is necessary on low-quality pasture and rangeland or when continuously grazing temperate warm-season pastures.For more information, see the ATTRA publication Ruminant Nutrition for Graziers. This publication provides managers with tools and references to consider biological and climatological variables and make decisions that ensure the ecological and economic viability of a grass-based ruminant livestock operation.