Combining Forage and Cover Crop Benefits from Cool-season Annuals in the Southeastern United States

Abstract

Cow-calf operations in the southeastern United States (U.S.) are based on warm-season perennial grass pastures. Stored forage feeding during the non-grazing season constitutes more than half of a cattle operation’s annual expenses. Cool-season annuals can extend the grazing season, thereby reducing stored forage feeding. A two-year field trial was conducted to determine the forage potential of a variety of crops commonly used as winter cover crops in the southeastern U.S. The ten cover crop treatments included seven monocultures (annual ryegrass [Lolium multiflorum], rye [Secale cereal], oats [Avena sativa], triticale [Triticale hexaploide], tillage radish [Raphanus sativus], hairy vetch [Vicia villosa], crimson clover [Trifolium incarnatum]) and three mixtures. Harvests were made in late winter and early spring of each year. Spring harvest yielded more than twice as much dry matter (DM) as winter harvest across all treatments. Total dry matter yield per treatment ranged from 2,066 to 3,732 kg ha-1. Neutral and acid detergent fiber concentrations increased about 10% from winter to spring. Crude protein decreased about 8% between harvests, however, overall crude protein concentrations were high enough to meet the nutrient requirements of lactating cows and growing calves, ranging from 17 to 25% in winter, and 11 to 22% in spring. All treatments proved to be highly digestible according to in vitro true digestibility analysis, ranging from 72-90% digestibility. High nutritive value across all treatments indicates feasible usage as winter forages and potential reduction of cattle production cost. Multispecies forage mixtures produced yields similar to monocultures with less risk from environmental impact and potential for a more evenly distributed yield.