Forage Characteristics Affecting Meat Goat Preferences for Forage Chicory Cultivars

Abstract

Concentration of bitter sesquiterpene lactones (SL), lactucin, lactucopicrin, and 8‐deoxylactucin, has been associated with low soil P fertility and reduced livestock preference for forage chicory (Cichorium intybus L.). We evaluated the effect of cultivar and available soil phosphorus (ASP) on meat goat (Capra hircus L.) preferences for ‘Grasslands Puna (Puna)’ ‘Forage Feast,’ and ‘INIA le Lacerta (Lacerta)’chicory grown under varying P fertility. Soil Bray‐P was used to designate ASP as low (LP, mean 8.6 mg kg−1), medium (MP, 21.7 mg kg−1), and high (HP, 40.1 mg kg−1) for the preference test. In September, clipped fresh forage was offered to confined Boer‐cross goat kids using a replicated 3 by 3 Latin square design with an extra period. Preferences were measured using dry matter intake for cultivar effects and multidimensional scaling (MDS) for ASP effects. Across cultivars, soil Bray‐P was positively related to leaf P and Mg concentrations. Soil Bray‐P did not affect lactucopicrin or 8‐deoxylactucin, and was positively associated with lactucin, in contrast to the hypothesis. Goats exhibited no preferences among cultivars despite up to fourfold differences in individual SL. Within cultivars, goats preferred Puna with less lactucin and total SL, Lacerta with less lactucopicrin and leaf Mg, and Forage Feast with more cell wall. Goats were able to detect relatively small differences in SL within cultivars, but this had little practical effect on intake of the forage because they ate it even when bitter. Therefore, P fertilization for fall‐grown chicory is unlikely to improve forage intake in goats.