Forage Utilization and Beef Cow Nutrition
A grazing study was conducted to evaluate the impact of legumes and warm-season grasses on season-long productivity of complementary grazing systems. Eight complementary and four continuous grazing systems were evaluated. Cool-season pastures used for the study consisted of smooth bromegrass alone or in mixture with birdsfoot trefoil, alfalfa, or kura clover. Warm-season pastures were monocultures of big bluestem or switchgrass. Pastures were established at the McNay Research Farm near Chariton, IA, over a two-year period starting in 1994. Grazing systems were designed on the basis of a fixed seasonal carrying capacity and pastures were stocked accordingly with growing cattle throughout the grazing period in 1997, 1998, and 1999. In 1997, animals that grazed warm-season pastures during the summer gained less weight than those that grazed cool-season pasture for the entire season, and there were no differences in total gains due to cool-season pasture species. Growing conditions in 1997 were cool and wet and therefore very conducive to growth of cool-season species. In 1998, animals grazing big bluestem pastures during summer performed as well or better than those remaining on cool-season pastures at a lower stocking rate. Birdsfoot trefoil and kura clover pastures produced higher gains regardless of which summer pasture was grazed. Results in 1999 were similar to those in 1998 except that birdsfoot trefoil pastures did not produce as well. Production from switchgrass pastures was improved in 1999 by removing initial spring growth as hay prior to the summer grazing period.
Iowa State University
Moore, K. J.; Hintz, R. L.; Wiedenhoeft, M. H.; Brummer, E. C.; and Russell, J. R., "Sequential Grazing Systems for Beef Cattle Production" (2002). Beef Research Report, 2001. 15.