Yield, Morphological Characteristics, and Chemical Composition of European- and Mediterranean-Derived Birdsfoot Trefoil Cultivars Grown in the Colder Continental United States

North American birdsfoot trefoil (BFT, Lotus corniculatus L.) cultivars such as Norcen produce forage with low condensed tannin (CT) concentrations that may be insufficient for optimal livestock performance. Our objective was to identify European-and Mediterranean-derived cultivars with higher CT concentrations that would be suitable for production in the colder continental United States. One alfalfa (Medicago sativa L.) and 14 BFT cultivars were established during 2005 in MI, UT, WI, and WV and harvested under a two-or three-cut management to determine herbage chemical composition in 2006 and dry matter yield (DMY) in 2006 and 2007. During 2006, variances in crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) were mainly influenced by location-harvest environments, while CT was influenced by both cultivar and environment. Earlier-maturing cultivars such as Bokor, AU Dewey, Rodeo, and Grasslands Goldie produced herbage with relatively high CT concentrations, but not undesirably low CP or high NDF, ADF, and ADL concentrations compared with Norcen BFT or alfalfa. By the second full production year in 2007, total DMY in UT exceeded WI by twofold and MI by ninefold, and total DMY of the moderate CT-containing cultivar Lotar surpassed most other cultivars, suggesting it may be well suited for forage production in the United States. Yields of alfalfa in all environments exceeded BFT by about 1.5-fold. Additional studies are needed to identify optimal CT concentrations in BFT for ruminants and to improve the compositional uniformity and yield of harvested BFT in various environments.