It is common for cattle grazing summer pastures in Mississippi to be provided with a mineral and vitamin supplement but no grain-based supplement. In many cases stocking rates are such that summer forages provide adequate or even excessive dry matter availability for grazing cattle to consume. Yet supplementation with concentrate feeds during the summer is not out of the question as a reasonable practice on cattle operations. It all depends upon the situation.
Supplementation may be used to improve the overall diet quality of cattle grazing summer pasture. It is well documented that summer forages typically have less crude protein and total digestible nutrients concentrations than winter forages. Of course, forage species and management affect this, particularly management of forage maturity. Similarly, late summer pastures may need supplementation even more so than earlier summer pastures because of the decline in nutritive value over the course of the growing season.
Supplementation may be worthy of consideration in cases where forage availability is less than desired. This might occur during a drought, after poor forage stand establishment, or when there is a loss of grazing acreage, such as when a pasture lease expires and is not renewed. Decreasing stocking rates by adding grazing acreage or removing animals from the herd could be done to address limited forage availability. In cases where a producer does not want to sell any cattle at the current time and cannot or will not add pasture acreage, then shifting cattle onto a diet with a greater percentage of grain in place of forage could be used to tide them over until a time when available forage becomes more abundant. Supplementation in these cases may need to involve stored forage such as hay or baleage in addition to concentrates. If nothing is done when forage quantities are insufficiently matched to cattle nutrient demands, then cattle performance will clearly suffer.
Whether or not grain supplementation is warranted varies with operational goals, pasture type, time of year, supplement type, supplementation rate, pasture and supplement costs, and cattle prices. Producers should first define their purpose(s) for supplementation. Is the idea to improve profitability through better growth performance or enhanced reproductive performance? Is the primary goal to meet specific performance targets, such as those for contract grazing or board sale specifications? Is supplementation being considered as a means to get calves used to consuming feed? Is it an option because there is a desire for cattle to be trained to come to feed? The reason behind providing the supplement will drive decisions on what, when, and how much to supplement.