Evaluation of Alfalfa (Medicago sativa) and Sericea Lespedeza (Lespedeza cuneata) to Improve Animal Performance in a Tall Fescue-Based Grazing System

Tall fescue [Schedonorus arundinaceous (Schreb.) Dumort. nom. cons. Lolium arundinaceum Darbysh.] is the dominant pasture grass across much of southeast USA. The species productive, but grows slowly in summer. Plants also harbor an endophytic fungus (Epichloe coenophiala), which produces alkaloids that are toxic to cattle. Adding summer-productive forages fescue-based systems may benefit animal production by providing extra herbage and diluting toxins. A three-year study was conducted Virginia, USA determine vegetation responses when alfalfa (Medicago sativa) or Sericea lespedeza (Lespedeza cuneata (Dum. Cours.) G. Don) swards were established into tall pastures. Average daily gain (ADG) steers seasonal mass dynamics monitored from 2016 2018. Forage weed composition measurements collected address a secondary objective sericea might suppress weeds through allelopathy. Steer performance acceptable (0.73 kg d?1 ADG), interseeded legumes did not improve weight gain. Steers avoided plants, this resulted greater accumulation summer compared with other treatments. Alfalfa selectively grazed cover decreased almost zero year 3, while increased over 82%. We found little evidence allelopathic against weeds. Neither legume proved be satisfactory improving grazing system.