ABSTRACT


CLAUDIO WERNIL K.1, JUAN JOSÉ ROMERO T.2 Y HERNÁN CABALLERO D.3
 
This research project was conducted at the La Platina Experiment Station of the Instituto de Investigaciones Agropecuarias - Chile, during 1965. The main purpose of this study was to determine the proper time to harvest the corn silage variety Eureka, in relation to yields, rate of intake, nutritive value and properties of the silage.Twelve Holstein steers (436 Kg.) were divided in two groups, and kept in partially roofed corrals. Two types of com silage were used: a milky stage with 23% dry matter (D. M.) content and a hard dough stage com silage with 34% D. M., both fed ad libitum. In adition, both groups were fed daily 2 Kg. of hay per steer and a mineral mixture according to requirements.At the same time, digestibility of Dry matter, Organic matter, Protein and Energy of the two rations were determined with lambs.Higher yields of D. M. and T. D. N. (total digestible nutrients) per hectare were obtained with the hard-dough stage silage. However, its high D. M. content did not permit proper packing of the roughage, causing much higher total losses during the storage period as compared with those that occured in the silage harvested earlier. Fresh silage intake was higher, but D. M. intake was lower for the milky stage silage, when compared with the hard-dough stage corn silage. Nutritive value of the hard-dough corn silage was higher as fed and average daily gains were little higher (but not significantly) when compared with those rations based on the more immature silage. The efficiency of the D. M. in both silages was very similar. It was concluded that there is no advantage in harvesting the corn silage variety Eureka with the grain at a hard-dough stage when the roughage will be stored in bunker silos or similar type of facilities. In general, harvesting should be made according to the stage of stalk dryness rather than according to the grain consistency, thus avoiding harvesting this forage with a high D. M. content.
Keywords:
1 Ingeniero Agrónomo, Proyecto Producción Animal, Estación Experimental La Platina, Instituto de Investigaciones Agropecuarias. Profesor Auxiliar Cátedra Alimentación, Facultad de Agronomía, Universidad de Chile.
2 Ingeniero Agrónomo M. S., Proyecto Producción Animal, Estación Experimental La Platina, Instituto de Investigaciones Agropecuarias. Profesor Auxiliar Cátedra Producción Lechera, Facultad de Agronomía, Universidad Católica de Chile.
3 Ingeniero Agrónomo Ph. D., Coordinador del Programa Ganadería del Instituto de Investigaciones Agropecuarias. Pr