@article {51356, title = {Effects of Flourensia cernua ingestion on nitrogen balance of sheep consuming tobosa}, journal = {Journal of Range Management}, volume = {49}, year = {1996}, note = {Permission to post articles granted by the Society for Range Management; www.rangelands.org.}, month = {1996}, pages = {331-335}, abstract = {

Flourensia cernua DC. (tarbush) is a deciduous shrub with potential as a high-protein forage source for livestock. Twenty-four Polypay x Rambouillet wethers housed in metabolism crates were used to evaluate tarbush as a N source for sheep fed a low quality grass diet. Treatments were 100\% ground tobosa grass (Pleuraphis mutica Buckl.) or tobosa substituted with 10, 20, or 30\% whole pre-bloom tarbush leaves (n = 5) or 26\% ground alfalfa (n = 4, Medicago sativa L.) on a dry matter basis (dmb). Sheep were fed ad libitum for 11 days, after which feed was restricted to 1 \% (dmb) of body weight for 11 days to reduce sorting and maintain uniform intake. Apparent dry matter digestibility was not improved (P = 0.2646) with tarbush or alfalfa. Fecal N was similar (P = 0.1626), but urinary N varied (P = 0.0008) among treatments. Apparent N digestibility differed (P = 0.0042) among treatments (43, 46, 50, 56, and 63\% for sheep consuming 0, 10, 20, or 30\% tarbush or alfalfa, respectively). All treatments resulted in similar (P = 0.1569) but negative N retentions (-2.4, -2.2, -2.8, -2.0, and -1.5 g day-1 for sheep consuming 0, 10, 20, or 30\% tarbush or alfalfa, respectively). Serum clinical profiles (day 22) confirmed all sheep were nutritionally stressed, but did not indicate toxicosis. Although neither tarbush nor alfalfa N compensated for the low quality basal diet, N from 30\% tarbush was utilized with similar efficiency to alfalfa N. The major impediment for using tarbush as a N source appeared to be low palatability.

}, keywords = {alfalfa, blood chemistry, body weight, cholesterol, digestible protein, dry matter, feed intake, Flourensia, grasses, Leaves, New Mexico, nitrogen balance, nitrogen retention, Pleuraphis mutica, sheep, urea, weed palatability}, url = {/files/bibliography/497.pdf}, author = {D. King and E.L. Fredrickson and Richard E. Estell and Kris Havstad and Wallace, J.D. and L. W. Murray} } @article {51438, title = {Relationship of tarbush leaf surface secondary chemistry to livestock herbivory}, journal = {Journal of Range Management}, volume = {47}, year = {1994}, note = {Permission to post articles granted by the Society for Range Management; www.rangelands.org.}, month = {1994}, pages = {424-428}, abstract = {

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.

}, keywords = {Epicuticular wax, herbivores, Leaves, livestock, monoterpenes, Plant biochemistry, plants, shrubs, terpenes, terpenoids}, doi = {10.2307/4002991 }, url = {/files/bibliography/418.pdf}, author = {Richard E. Estell and E.L. Fredrickson and D.M. Anderson and W. Mueller and M.D. Remmenga} }