|Title||Effects of cis-beta-sabinene hydrate, and monoterpene adn sesquiterpene mixtures on alfalfa pellet intake by lambs|
|Publication Type||Journal Article|
|Year of Publication||2008|
|Authors||Estell, RE, Fredrickson, EL, Anderson, DM, Remmenga, MD|
|Journal||Journal of Animal Science|
The transition of grasslands to shrub-dominated scrubland reduces livestock productivity and contributes to impoverished human conditions in arid and semiarid regions worldwide. Many shrubs increasing in dominance contain secondary compounds that deter herbivores. Knowledge concerning the effects of specific compounds on 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 individual terpenes (cis-â-ocimene and cis-sabinene hydrate; Exp. 1 and 2) or mixtures of monoterpenes (borneol, camphene, camphor, 1,8-cineole, limonene, myrcene, and á-pinene; Exp. 3) or sesquiterpenes (â-caryophyllene, caryophyllene oxide, á-copaene, and á-humulene; Exp. 4) on intake of alfalfa pellets by lambs. Forty-five lambs (9 lambs/treatment) were individually fed treated alfalfa pellets for 20 min each morning for 5 days. Five treatments (0X, .5X, 1X, 2X, and 10X; multiples of the concentrations of the same terpenes in Flourensia cernua) were applied to alfalfa pellets (637 g, DM basis) in an ethanol carrier. Experiments were preceded by a 10-d adaptation period to untreated pellets. Except during the 20-min test, lambs were maintained outdoors and fed untreated alfalfa pellets (total mean intake = 4.7% of BW, DM basis). Day × treatment interactions were detected (P< 0.04) in Exp. 1 and 4, due to greater intake for 0X than other treatments on day 1 (Exp. 1) and lower intake for the 10X treatment on day 1 and 2 (Exp. 4). A trend for decreased intake (g/kg BW) as concentration of the sesquiterpene mixture increased was observed in Exp. 3 (P = 0.093 for the linear contrast). Although there was a tendency for the sesquiterpene mixture to decrease intake, cis-â-ocimene, cis-sabinene hydrate, and the monoterpene mixture did not appear to affect intake by lambs. Thus, sesquiterpenes may exert antiherbivory properties under certain conditions that may contribute to shrub dominance with extended periods of livestock foraging.