Seasonal quality profile and production of foliage from trees grown on degraded cropland in arid Uzbekistan, Central Asia

Feed shortages hamper livestock rearing and thus impede the development of rural livelihoods in Central Asia. The production and in vitro quality of foliage from Ulmus pumila, Elaeagnus angustifolia and Populus euphratica on degraded cropland were examined to determine the potential of these species to supplement dairy cattle diets. Leaf dry matter (DM) production of the species, respectively, averaged 6, 8 and 17 t DM/ha, 4 years after planting. Over seasons and years, crude protein concentrations (g/kg DM) ranged within 151-257 for E. angustifolia, 70-241 for U. pumila and 92-187 for P. euphratica. The metabolizable energy concentrations (MJ/kg DM) were the highest in U. pumila and ranged within 9-10, followed by 7-10 of E. angustifolia and 7-9 of P. euphratica. The organic matter digestibility (%) ranged within 58-70, 54-66, and 51-66, respectively, for these species. These indicators combined denoted a medium-to-good feed quality of E. angustifolia and U. pumila leaves as a cheap protein supplement to roughages. The foliage of P. euphratica was the least suitable. The seasonal profile of in vitro indicators revealed the highest feed quality in spring but early fall seems most appropriate for forage collection given the peak leaf production and an adequate quality.