Ignacio Ruiz N.1, Ernesto Jahn B.2, Germán Klee G.3, Marcos Figueroa R.4 y Alejandro Ayres M.5

An experiment was carried out during 1969-70 at the Quilamapu Experiment Station, Chillán, to study the influence of 3 rates of winter gain of Holstein steers from 8-12 months of age period (first winter of spring-born claves) on a total beef production system based on a year-round forage program.
The treatments and results were: a) High winter gain (0.79 Kg/day) obtained by winter grazing plus a dry sugar beet pulp-rapeseed meal supplement; b) Medium gain (0.38 Kg/day) obtained by grazing plus hay harvested from the forage plan, and c) Maintenance (-0.02 Kg/day) obtained with grazing alone. In the subsequent spring-summer-fall grazing season, the steers at the maintenance level showed the highest daily gain, but by fall they did not reach the live weight of steers from the other treatments; thus at the beginning of the second winter the steers 20 months old were not heavy enough to complete winter fattening within a 2 years-system of production. After the grazing period, the steers of all treatments were fed with a similar winter fattening ration (20-24 months of age).
The treatments markedly influenced the carrying capacity and the output per hectare as well as the time to reach market weight (500 Kg).

1Ing. Agr., Ph. D., Estaci6n Experimental Quilamapu, Instituto de Investigaciones Agropecuarias (INIA), Casilla 426, Chillán, Chile.
2Ing. Agr., M. S., Subestación Experimental Humán, Caoilla 767, Los Angeles, Chíle. Actualmente en V. P. I. y S. D., Blacksburg, Virginia.
3Ing. Agr., Subestación Experimental Humán, Casilla 767, Los Angeles.
4Ing. Agr., M. S., Estación Experimental Quilamapu, Chillán.
5Ing. Agr., Estación Experimental Quílamapu. Actualmente funcionario del Servicio Agrícola Ganadero (SAG)