Extensive sheep production system on annual range of the dryland subhumid Mediterranean zone

Julia Avendaño R. 1, Carlos Ovalle M. 2 y Teresa Aravena A.1

During six (raising) seasons this system was evaluated under a dryland annual range, on continuos grazing, as the only feeding source. The highest sales and liveweight net productions occurred in the sixth season, followed bythose ofthe second season, and finally by those with the least deviation from the mean, in the fourth season. Weaning or reproductive efficiency rate in the sixth, second and fourth seasons and the mean of the six seasons were 108.8, 90.9, 100.0 and 99.3%; ewe production (Iiveweight ofweaned lamb) was 35.2, 29.5, 33.1 and 33.0 kg, respectively. The Iiveweight sales and the net Iiveweight production were 30.0 and 31.2 in the sixth;19.1 and 22.9 in the second; 24.3 and 25.9 in the fourth season; and the mean of the six seasons was 24.8 and 25.1 kg/ha, respectively. The lowest annual net production (second season) was 92.4% higherto than of an average local sheep breeding place (11.9 kg/ha) (survey from seas on 1973/74).

Keywords: sheep production system. mediterranean zone, extensive sheep production, rangelands systems.
1 Campo Experimental Cauquenes (INIA), Casilla 165, Cauquenes, Chile.
2 Centro Regional de Investigación Quilamapu (INIA), Casilla 426, Chillán, Chile.