Tarbush (Flourensia cernua DC.) contributes substantially to the Chihuahuan Desert shrub biomass, but is browsed sparingly by livestock. This study was designed to assess nutritional benefits and/or toxicosis of ingestion of pre-bloom tarbush leaves by sheep fed a low quality native grass diet. Sixteen ruminally cannulated sheep (46 kg) housed in individual pens were randomly assigned to 1 of 4 treatments for 28 days. Treatments were ground tobosa grass (Pleuraphis mutica Buckl.) substituted with 0, 10, 20, or 30% (dry matter basis) whole tarbush leaves (19% CP). At 20 and 30% of the diet, tarbush increased (P = 0.0049) dry matter intake during week 3, and sheep consuming 30% tarbush tended to increase dry matter intake during week 2 (P = 0.0559). Dietary tarbush did not affect any variable associated with ruminal fluid kinetics, particulate digesta kinetics, or in situ degradation rates of tobosa dry matter or neutral detergent fiber (P > 0.05). Molar butyrate proportions (P = 0.0032) and total volatile fatty acid concentrations (P = 0.0064) were greater for the 30% tarbush treatments. Ruminal ammonia was greater (P < 0.0029) at 6, 8, and 12 hours postfeeding for the 30% tarbrush treatment. Sheep lost body weight regardless of treatment; however, sheep not fed tarbush boded (P = 0.0945) to lose more weight. &rum clinical profiles (day 0, 7, 15, and 21) confirmed nutritional stress but did not suggest toxicosis. The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information. Migrated from OJS platform August 2020
Scholarly peer-reviewed articles published by the Society for Range Management. Access articles on a rolling-window basis from vol. 1, 1948 up to 5 years from the current year. Formerly Journal of Range Management (JRM). More recent content is available by subscription from SRM.