Diet and Performance of Sheep on Rangeland in Semiarid Argentina

Abstract

During 1968 a study was conducted with sheep grazing sandhill pasture in the semiarid area of Argentina. Measurements made included botanical analyses of forage available, forages selected, intake, body weight, and wool growth. Botanical analyses showed that sheep selected their diet from species comprising less than one-fourth of all forage available. Two coarse perennials, Sporobolus rigens and Hyalis argentea, representing between 64.0 and 84.8% by weight of all forages available, were not consumed by the sheep. The animals preferentially grazed certain species even when these species were available in very low amounts. Digestible organic matter intake, body weight, and wool production followed a similar pattern. An inadequate intake of energy would appear to be the most serious nutritional deficiency identified by this study.