Effects of cis-β-ocimene, cis-sabinene hydrate, and monoterpene and sesquiterpene mixtures on alfalfa pellet intake by lambs

The transition of grasslands to shrubdominated scrubland reduces livestock productivity and contributes to impoverished conditions for humans in arid and semiarid regions worldwide. Many shrubs that are increasing in dominance contain secondary compounds that deter browsing by herbivores. Knowledge concerning the effects of specific compounds in herbivore diets is limited but may provide useful insights into desertification. Flourensia cernua is a dominant shrub in the northern Chihuahuan Desert that contains an abundance of terpenes. Four experiments were conducted to determine the effects of terpenes on intake of alfalfa pellets by lambs. Two individual monoterpenes (cis-β-ocimene and cis-sabinene hydrate) were examined in Exp. 1 and 2, and mixtures of monoterpenes (borneol, camphene, camphor, 1,8-cineole, limonene, myrcene, and α-pinene) and sesquiterpenes (βcaryophyllene, caryophyllene oxide, α-copaene, and αhumulene) were examined in Exp. 3 and 4, respectively. Forty-five lambs (9 lambs/treatment) were individually fed treated alfalfa pellets for 20 min each morning for 5 d. Five treatments (0×, 0.5×, 1×, 2×, and 10×; multiples