EFECTO DEL MES DE NACIMIENTO SOBRE EL CRECIMIENTO DE TERNEROS EN PASTOREO BAJO LAS CONDICIONES DE LA PROVINCIA DE OSORNO

Abstract

An experiment, was carried out at the Barro Blanco Sub-Experimental Station, Instituto de Investigaciones Agropecuarias in Osorno, to measure the effect of the month of birth on the growth of 0-6 month old calves. This, was done between August 1, 1971 and July 30, 1972.
Sixty-four Holstein calves were used and, according to their date of birth were put on five different treatments which corresponded to those born in August-September-October-November and December.
Nutrition was based on whole milk and pasture: having the animals access to the prairie from birth. Once the animals reached 80 Kg liveweight, weaning was done. The predominant species on the prairie were white clover, orchard grass, velvet grass and rye grass. Trying to make the best use of the prairie, rotative pasturing was done.
Results obtained show that calves born between late winter and early spring have better growth than those born between late spring and early summer. Under the condtions the experiment was carried out, the weight reached by six month old calves would be insufficient for the breed.