ChileanJAR

A beef productiori system, based on calves soid at weaning, was evaluated over three growing cycles, at the Cauquenes Experiment Station (INIA), under the conditions of the Mediterranean subhumid dryland range of Chile. For each 100 mated cows, 91.5 calves were born alíve and 5.0 dead. Annual replacement of females vvas 19.2% and the herd mortality was 2.9%, averages for the three cycles. Average birth and weaning weights for the three cycles were 34.2 and 172.4 kg for males, and 31.9 and 162.9 kg for females, respectively. Seasonal average stocking rate for the three cycles was 0.31 animal units/hectare/year. Mated cows were divided tito three groups, according to their calf crop: first, second and third to sixth. Highest weights in spring time attained by these cows were 392 kg, for the first calving, 426 kg for the second and 459 kg. for the third tosixth, Between springand the next autumn, after catvesweaning cows in the three groups lost 11.7, 13.9 and 13.3% of their spring weight, respecrively. Heifers were mated at 26 months of age; their weíght at mating was 270, 320 and 330 kg for each cycle. The growth curve of the calves showed decreasing increments of weight from birth to weaning. Gains in uve weight/hectare/year were 53.3, 40.6 and 37.4 kg for each cycle, surpassing the average gain obtained by cattle breeding enterprises in the area (23.5 kg/ha/year). The economic analysis was done using commercial prices expressed in chilean pesos for september 1981. Gross income was $ 530, $ 176 and $ 610/ha for the first, second and third cycle, respectively. Return on investment (excluding land) was 7.0, 3.0 and 9.1%, for the same cycles, respectively. The production system developed during the third season, based on the natural pasture and winter suplementation with subterraneum clover-falaris-rye grass hay, was the most efficient economical alternative. Although the system can not be recommended as new investment proyect (because of present high interest rate)