Evaluating Cow/Calf and Stocker Performance when Grazing Sudangrass With and Without Sunnhemp

Summary with Implications Sudangrass can provide high-quality summer forage, supporting cow/calf pairs and growing cattle. In this study, sudangrass or a sudangrass–sunnhemp mix was grazed over two years by cow/calf pairs and heavy stockers (~880 lb). There was no difference in carrying capacity between forage types. Sunnhemp inclusion had no effect on cow body condition or nursing calf gain. Cows maintained condition through peak lactation, and nursing calves gained 2.27 lb/day. Stockers gained 1.56 lb/day on sudangrass alone and 1.73 lb/day on the mix. However, the added seed cost of sunnhemp increased the cost of gain in year 1 and resulted in only a breakeven return in year 2. From a forage perspective, adding sunnhemp increased seed cost without improving forage production or grazing days. Based on this study, sunnhemp inclusion into sudangrass does not provide an economic advantage for cow/calf or stocker systems.