ABSTRACT.


IGNACIO RUIZ N.1
 

On a red clover pasture the effects of different winter grazing treatments upon animal and pasture performance were compared. Under stocking rates of 2 and 4 steers pey hectare, steers weighting 379 Kg. with limited supplement were compared with other steers that grazed only. In addition, in the subsequent grazing season, a comparison was made between the production of pasture without winter grazing and that of the pasture treated as described above.
When the steers received 4.0 Kg. of dried beet pulp daily plus 0.4 Kg. of rape meal, the daily gain was 0.476 and 0.408 Kg. with stocking rates of 2 and 4 animals per hectare, respectively. On the other hand, the steers without supplementation lost 0.172 and 0.504 Kg. daily at stocking rates of 2 and 4 animals per hectare, respectively. However, during the following spring-summer grazing period, the steers that gained the most during the winter season gained the least on pasture; nevertheless, the winter supplemented steers needed less time to attain the final weight of 530 Kg.
As the winter treatment was more rigorous, there was more damage to the pasture at the end of the winter. However, this was not clearly reflected as a difference in the liveweight production per hectare during the following grazing season (spring-summer-fall). Only the pasture that was not grazed during the winter gave an appreciably higher liveweight output per hectare as compared to the other treatments.

Keywords:
1 Ingeniero Agrónomo M. S., Estación Experimental Chillán, Instituto de Investigaciones Agropecuarias