Seasonal Fluctuations in Nutrient Content of Feral Burro Forages, Lower Colorado River Valley, Arizona

Abstract

Nutrient contents of wooly Indianwheat, white bursage, desertthorn, and foothills paloverde were determined seasonally during 1974 and 1975 in the Havasu Resource Area, California-Arizona. Gross energy content showed the least seasonal variation. Crude protein, phosphorus, and beta-carotene contents increased during the pulse of growth produced by winter precipitation, then slowly declined. Although the forage species analyzed appeared to be deficient in phosphorus, feral burros in the study area appear to be in excellent health.