@proceedings {JRN53998,
	title = {Relationship between one-seed juniper terpene concentration and herbivory by small ruminants},
	volume = {91},
	year = {2013},
	month = {07/2013},
	pages = {553},
	publisher = {Journal of Animal Science},
	address = {Indianapolis, IN},
	abstract = {<p>Plant secondary metabolite affect the amount of use by herbivores for serveral woody species.\&nbsp; We examined the relationship between terpenoid concentrations and Juniperus monosperma herbivory by small ruminants.\&nbsp; The study was part of a larger effort in which goats (n = 10) or mixed species (5 goats and 4 sheep) were allotted to 16 plots (20 \&times; 30 m) containing one-seed juniper for 6 d during 2 seasons at 2 stocking rates. Juniper leaves were sampled from 311 saplings on the same day they were browsed. Saplings were categorized by size (small [\&lt;0.5 m], medium [0.5-1.0 m] or tall [\&gt;1.0 m]) and browsing intensity (low [\&lt;33\%], moderate [33-66\%] or heavy [\&gt;66\%] herbivory). Juniper bark was also collected from 12 saplings during spring. Leaves and bark were analyzed for terpenoids with gas chromatography-mass spectrometry. Terpene data were pooled across species and stocking rate and ANOVA was conducted for season, sapling size, and herbivory level. The volatile profile of one-seed juniper leaves and bark consisted of 65 and 55 compounds, respectively. Total estimated terpenoid concentrations in leaves and bark were 18.3 \&plusmn; 0.3 and 8.9 \&plusmn; 0.8 mg/g, respectively, and the dominant terpene in both tissues was \&alpha;-pinene (11.1 \&plusmn; 0.2 and 7.6 \&plusmn; 0.7 mg/g, respectively). Total terpenoid concentration was greater (P \&lt; 0.001) in spring than summer (20.6 \&plusmn; 0.5 vs. 16.7 \&plusmn; 0.3 mg/g, respectively) and lower (P \&lt; 0.001) in small saplings than medium or tall saplings (16.5 \&plusmn; 0.6 vs. 19.8 \&plusmn; 0.4 and 19.5 \&plusmn; 0.4 mg/g, respectively). Total concentration also differed (P \&lt; 0.001) among all 3 browsing categories (16.1 \&plusmn; 0.4, 18.7 \&plusmn; 0.5, and 21.2 \&plusmn; 0.6 mg/g for heavy, moderate, and light herbivory, respectively). Approximately 42\% of the variation in browsing intensity could be explained (P \&lt; 0.001) by 12 compounds ([E]-\&beta;-farnesene, cis-sabinene hydrate, bornyl acetate, \&gamma;-eudesmol, germacrene A, \&gamma;-cadinene, \&alpha;-pinene, [Z]-\&beta;-ocimene, terpin-4-ol, cispiperitol, cis-p-menth-2-en-1-ol, and camphene hydrate). Our results indicate that the terpene profile of one-seed juniper is related to sapling size, season, and degree of use by sheep and goats.</p>
},
	keywords = {goat, sheep, terpene},
	author = {Richard E. Estell and S. A. Utsumi and Andr{\'e}s F. Cibils and D.M. Anderson}
}
