HARVEST ALTERNATIVES TO REDUCE THE ALKALOID CONTENT OF REED CANARYGRASS FORAGE

Growing conditions favorable to the accumulation of alkaloids in reed canarygrass (RCG) can result in gramine concentrations exceeding toler able levels for grazing animals. Alternative harvest techniques for th is forage material include silage and hay production. A replicated tri al with 22-L mini-silo units showed that gramine and hordenine concent rations in RCG herbage do not decrease as a result of ensiling. Reed c anarygrass regrowth cut and field-wilted to 74.9% dry matter (DM) had reduced (P < 0.05) gramine and hordenine concentrations. A second tria l using RCG regrowth, dried under laboratory controlled conditions als o showed decreases (P < 0.05) in forage gramine and hordenine concentr ations. Hay_ baled at 73.1% DM and stored for 32 d had a further reduc tion (P < 0.05) in hordenine concentrations. No change in gramine conc entration was observed during storage of forage as hay, but this may b e due to low initial levels in the baled hay. An intake and digestibil ity study with growing ram lambs showed DM and neutral detergent fiber digestibilities for the beta-carboline and tryptamine free cultivars, Rival and Venture, to be comparable to timothy, cultivar Champ, when regrowth was cut at the same stage of maturity. This study suggests th at RCG forage considered to be too high in gramine for grazing animals could be harvested as hay to reduce forage alkaloid concentrations.