El enfoque energético en la producción de la hierba

Abstract

Grassiand, moreover other roles, play the very important one of being the only alternative to convert solar radiation into feed and food energy on may soil conditions and with a minimun cost of suport energy when herbage cover is utilized by grazing animáis. Energy balance do not substitute ecconomy account, but are useful to compare the technical efficiency of diferent grassiand systems in the use of solar radiation and/or support energy to yield each product. A calculation of potential DM yield (stored energy) and relative efficiency based on a total solar radiation receipt of 40 x 106 kcl ha-' d-> gives 449 kg ha ' d-' of total DM and 4,7 %, respectively. Several examples are given of relative efficiencies in the use of solar and support energy to produce DM ME and foods (milk, beef and lamb) under different grassiand and production systems in Spain and other countries. A method to calculated metabolizable energy utilized by milking cows from pasture is reported.