ChileanJAR

A physic system, with Herefords, was evaluated during four growing cycles at the Cauquenes Experimental Station (IN lA), under the conditions of the dryland range of Chile ("espinal"), with. winter supplemental feeding. Annual liveweight variations of the different categories of animals were analysed. Heifers weights at their first mating (26 months of age) were 306 to 327 kg, depending on the growing cycle. Calves weaning weights (185 to 212 days of age) oscillated between 172.2 and 216.2 kg. Pregnancy and calves born alive indexes were 76.0 and 90.3%, respectively. Total weaned calves/ cow was equivalent to 117.6 kg, average for the four cycles. Stocking rates and annualliveweight productions (sales) were 0.24, 0.14, 0.16, and 0.15 animal units/ haand 58.9,20.9, 35.2, and 27.7 kg/ha, from the first to the fourth growing cycle, respectively. The global and per cow productive efficiency in this autumn calving system were similar to those obtained in the zone with late winter calving; but the cows' reproductive efficiency was lower.