MANAGEMENT TECHNOLOGIES FOR ARID RANGELANDS
Location: Range Management Research
Title: Measurement of monoterpenes and sesquiterpenes in serum, plasma, and rumen fluid from sheep
Submitted to: Animal Feed Science And Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 12, 2010
Publication Date: May 1, 2010
Citation: Estell, R.E., Utsumi, S.A., Cibils, A.F. 2010. Measurement of monoterpenes and sesquiterpenes in serum, plasma, and rumen fluid from sheep. Animal Feed Science And Technology. 158:104-109.
Interpretive Summary: Shrubs encroaching into grasslands can be detrimental to both livestock production and ecosystem services. Many invasive shrubs are high in terpenes and are eaten in limited amounts by small ruminants, but little is known about how these chemicals are processed after consumption. To better understand the impact of terpenes on livestock, their absorption, distribution, degradation, and elimination must be determined. The method presently accepted for plasma was examined for suitability in serum and rumen fluid from sheep, using a wide range of terpenes varying both in size and structure. Generally, terpene recovery was greater from serum and plasma than rumen fluid, and terpenes containing oxygen were typically recovered more efficiently than those with only carbon and hydrogen skeletons regardless of fluid matrix. This technique was suitable for measuring several terpenes in all three fluids from sheep.
Studies involving the consumption, metabolism, and elimination of terpenes by small ruminants consuming terpene-laden shrubs as well as those exploring the potential for natural products as rumen modifiers could benefit from a procedure that measures terpenes in both blood and rumen fluid and that is suitable for either serum or plasma. The objective of this study was to modify an existing procedure for plasma utilizing solid phase extraction/gas chromatography, and extend its use for measurement of structurally diverse mono- and sesquiterpenes in three fluids (serum, plasma, and rumen fluid) from sheep. Generally, terpene recovery was lower from rumen fluid than from serum or plasma, although the extent and direction of differences varied among chemicals. Fourteen terpenes (camphene, ß-pinene, a-terpinene, p-cymene, cis-ß-ocimene, 1,8-cineole, '-terpinene, terpinolene, linalool, camphor, longifolene, ß-caryophyllene, a-humulene, and caryophyllene oxide) were recovered from serum at approximately 100%. Recovery from rumen fluid was lower than for serum or plasma for most terpenes, but eight terpenes (p-cymene, 1,8-cineole, cis-sabinene hydrate, terpinolene, borneol, terpin-4-ol, a-terpineol, and caryophyllene oxide) were recovered at near 100%. Yet, 15 terpene recoveries were below 75% (tricyclene, a-pinene, camphene, sabinene, ß-pinene, myrcene, 2-carene, 3-carene, a-terpinene, cis-ß-ocimene, limonene, '-terpinene, longifolene, ß-caryophyllene, and a-humulene). Oxygenated monoterpenes were typically recovered in greater quantities and hydrocarbon monoterpenes were least effectively recovered with this method. The procedure is suitable for measurement and recovery adjustment of terpenes from serum, plasma, and rumen fluid of sheep.