Integrated models of livestock systems for climate change studies. 1. Grazing systems

The potential impact of climate change by the year 2050 on British grazing livestock systems is assessed through the use of simulation models of farmi ng systems. The submodels, consisting of grass production, livestock feedin g, livestock thermal balance, the thermal balance of naturally ventilated b uildings and a stochastic weather generator, are described. These are integ rated to form system models for sheep, beef calves and dairy cows. They are applied to scenarios representing eastern (dry) lowlands, western (wet) lo wlands and uplands. The results show that such systems should be able to ad apt to the expected climatic changes. There is likely to be a small increas e in grass production, possibly allowing an increase in total productivity in some cases.