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ARS Home » Plains Area » Las Cruces, New Mexico » Range Management Research » Research » Publications at this Location » Publication #210245

Title: Effects of individual terpenes and terpene mixtures on intake by lambs

item Estell, Richard - Rick
item Frederickson, Eddie
item Anderson, Dean

Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 3/7/2007
Publication Date: 7/9/2007
Citation: Estell, R.E., Fredrickson, E.L., Anderson, D.M., Remmenga, M.D. 2007. Effects of individual terpenes and terpene mixtures on intake by lambs. Journal of Animal Science Vol. 85 Suppl. I/J Dairy Sci. Vol. 90, Suppl. 1/Poult. sci. Vol 86. Suppl. 1:287-288.

Interpretive Summary: Rangeland degradation due to shrub encroachment is a major concern to livestock producers and land managers in the western United States and in arid and semiarid regions worldwide. Most invasive shrubs contain secondary compounds that reduce their consumption by herbivores, but knowledge concerning the effects of specific compounds is limited. Four experiments were conducted to determine the effects of individual terpenes (cis-beta-ocimene and cis-sabinene hydrate; Exp. 1 and 2) or mixtures of monoterpenes (borneol, camphene, camphor, 1,8-cineole, limonene, myrcene, and alpha-pinene; Exp. 3) or sesquiterpenes (beta-caryophyllene, caryophyllene oxide, alpha-copaene, and alpha-humulene; Exp. 4) on intake by lambs. After a 10-day adaptation period with untreated alfalfa pellets, lambs (n = 45) 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. 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 because of greater intake for 0X than other treatments on day 1 (Exp. 1) and lower intake for the 10X treatment on day 1 and 2 in Exp. 4. A trend for decreased intake (g/kg BW) as concentration of the sesquiterpene mixture increased was observed (P = 0.093 for the linear contrast; Exp. 3). Although there was a tendency for the sesquiterpene mixture to decrease intake, cis-beta-ocimene, cis-sabinene hydrate, and the monoterpene mixture did not appear to affect intake by lambs.

Technical Abstract: Secondary compounds present in shrubs on rangelands in the western United States are often aversive to livestock. However, effects of many of these compounds on intake have not been individually tested. Four experiments were conducted to examine effects of individual terpenes on alfalfa pellet intake by lambs. Forty five lambs (9 lambs/treatment) were individually fed alfalfa pellets sprayed with either eugenol, terpin-4-ol, alpha-terpineol, or methyl eugenol at one of five concentrations in an ethanol carrier. Treatments (0, 0.5, 1, 2, and 10X) were multiples of the concentration (X) of a specific terpene on the leaf surface of Flourensia cernua. Terpenes were applied to alfalfa pellets (0.64 kg.lamb^{ 1}^.d^{ 1}^, DM basis), and consumption was measured during a 20 min interval for 5 d. Lambs were adapted to handling and individual pen feeding for 10 d and were maintained and fed alfalfa pellets in one group (except during 20 min tests) at a mean total daily intake of 3.9% of BW (DM basis). A day effect (P < 0.0001) was detected for intake in all four experiments, but no day x treatment interactions were observed (P > 0.05). The day effect was generally due to lower intake of alfalfa pellets on day 1, except for the methyl eugenol experiment, in which lambs consumed more pellets on day 1. No treatment effects were observed (P > 0.05) for any of the four chemicals tested; thus, none of these chemicals were strongly related to intake of alfalfa pellets by lambs under the conditions of this study.