Submitted to: American Forage and Grassland Council Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 3/26/2002
Publication Date: N/A
Citation: Interpretive Summary: Forage chicory is a drought-tolerant, perennial forb that can improve seasonal distribution of herbage in pastures. It produces large quantities of dry matter, and excellent rates of live-weight gain have been achieved by ruminants grazing chicory pastures. In southern West Virginia, ruminants are reluctant to consume chicory herbage and discriminate among forage chicory cultivars. This study was undertaken to ascertain the chemical basis for differential responses of grazers to different chicory cultivars and to herbage produced in different locations. Important differences in concentrations of bitter constituents, sesquiterpene lactones, were found. Concentrations of these compounds in West Virginia-grown cultivars were dramatically higher than those in corresponding cultivars grown in Pennsylvania and were highest in the least preferred cultivar (Forage Feast), regardless of cultivation site. Data suggest that environmental factors influence the sesquiterpene lactone composition of forage chicory herbage and thereby impact palatability. Results are guiding efforts to define management strategies that will enable livestock producers with site limitations to take advantage of the positive attributes of forage chicory.
Technical Abstract: `Grasslands Puna' (Puna) chicory (Cichorium intybus L.) is a promising pasture component in Pennsylvania (PA). In southern West Virginia (WV), Puna is not relished by sheep, and other forage chicory cultivars vary in acceptability. Chicory contains bitter sesquiterpene lactones; therefore, this study was undertaken to determine whether sesquiterpene lactone composition might be related to observed animal feeding behaviors. Investigations included the cultivars Puna, `INIA le Lacerta' (Lacerta), and `Forage Feast'. Vegetative herbage was collected during the summer of 1998 from each of the three cultivars at a PA State University research farm near State College, PA and a USDA, ARS research farm in southern WV. Dried tissues were extracted with methanol, and sesquiterpene lactones were determined chromatographically. Total concentration of sesquiterpene lactones ranged from 1.03 (Lacerta) to 1.52% (dry matter [DM] basis) (Forage Feast) in cultivars grown in WV. Forage Feast contained the highest concentrations of the sesquiterpene lactones lactucin (.37%) and lactucopicrin (.94%) and the lowest concentration of 8-deoxylactucin (.22%). This was also the trend in PA-grown herbage, but the concentrations of total sesquiterpene lactones (.32 to .55%), and particularly lactucopicrin (.09 to .18%) were dramatically lower in PA samples. Data suggest that environmental factors influence the sesquiterpene lactone composition of chicory and thereby impact palatability of the herbage.