Exotic grass and shrub production evaluation and llama preference on the Bolivian Altiplano

Lack of nutritional forage during the dry season limits llama (Lama glama) production on the Bolivian Altiplano. Minimal supplementation with stockpiled energy-rich grasses and high-protein shrubs may improve the dry season nutritional status of llamas. The purposes of this study were first, to evaluate forage production on the Altiplano of cold-hardy, drought-resistant plants successful in the Intermountain Western United States and second, the acceptability of these species to llamas. Six species of grass (pubescent wheatgrass [Agropyron trichophorum], smooth brome [Bromus inermis], crested wheatgrass [Hycrest] [Agropyron cristatum × A. desertorum], weeping lovegrass [Eragrostis curvula], orchard grass [Dactylis glomerata], and timothy [Phleum pratense]) and 6 species of shrubs (black sage [Artemisia nova], fourwing saltbush [Atriplex canescens], saltbush [Atriplex halimus], mountain mahogany [Cercocarpus montanus], bitterbrush [Purshia tridentata], and forage kochia [Kochia prostrata]) were planted at three sites on the Altiplano and evaluated during the dormant season of the following 2 years. Data measuring row fill, biomass, and nutrient concentrations were collected for the grasses. Data measuring percent survival, biomass, and nutrient concentrations were collected for the shrubs. Preference trials including focal animal sampling and instantaneous-scan sampling evaluated the acceptance of these forages by llamas. During the first year, row fill among the grasses ranged from 30–96%. Smooth brome biomass increased from 3427 to 5420 kg dry weight/ha between years (p ≤ 0.01) and was the most productive grass measured. Crested wheatgrass also increased from 2487 to 4687 kg dry weight/ha (p ≤ 0.01). The most successful shrubs, forage kochia and fourwing saltbush, survived 75–90%. At one site, fourwing saltbush produced 638 kg dry weight/ha and forage kochia 616 kg dry weight/ha, more (p ≤ 0.01) than produced at the other sites (91–316 kg dry weight/ha). Among the grasses, the highest CP concentrations were found in crested wheatgrass (9.7%) and orchard grass (9.6%). Weeping lovegrass had lower (p < 0.01) CP concentration (3.7%). Forage kochia, contained 14.6% CP. Five grasses were similarly preferred receiving between 11 and 18% time grazed. Weeping lovegrass received less (p ≤ 0.01) at 1–2%. The llamas refused the shrubs completely. Considering biomass and acceptability, orchard grass, pubescent wheatgrass, and smooth brome are likely selections for dry season supplementation.