Relationship of tarbush leaf surface secondary chemistry to livestock herbivory

TitleRelationship of tarbush leaf surface secondary chemistry to livestock herbivory
Publication TypeJournal Article
Year of Publication1994
AuthorsEstell RE, Fredrickson E.L., Anderson D.M., Mueller W., Remmenga M.D.
JournalJournal of Range Management
Date Published1994
KeywordsEpicuticular wax, herbivores, Leaves, livestock, monoterpenes, Plant biochemistry, plants, shrubs, terpenes, terpenoids

Tarbush (Flourensia cernua DC.) is an abundant shrub native to the Chihuahuan desert. Limited use as a forage by ruminants has been observed. The objective of this studey was to eexamine the leaf surface chemistyr of tarbush inrelation to degree of use by ruminants. Mature tarbush leaves were collected on 2 sites during 2 periods approximately 2 weeks apart from plants exhibiting either high (>45%) or low (<10%) use when browsed by cattle, sheep, and goats confined to a small area (5 plants per use category for each site/period combination). A greater (P<0.05) concentration of epicuticular wax was detected on the leaf surface of plants used to a lower degree. Epicuticular wax concentration was 8.2 and 10.3% of the leaf dry matter for high and low used plants, repectively. Several leaf surface compounds were related to period, while site and degree of use were seldom related to individual mon- and sesquiterpenes measure in this study. Camphene and 10 unidentified compounds differed between periods (P 0.10). Two unidentified compounds were related to site (P < 0.10) and 2 others were related to use (P<.0.10). In summary, individual leaf surface compounds on tarbush do not appear to greatly affect degree of us of tarbush by livestock, but collectively ( based on epicuticular wax data), these compunds may influence the diet selected by browsing ruminants.