Abstract

A whole-farm model is being developed at Dexcel for researchers to simulate whole-farm system trials. Climate and management information is entered and the model utilises published sub-models for pasture growth and cow metabolism. The model predicts pasture and animal production. A test of the model’s validity in different New Zealand regions using climate, land and management information particular to each region was undertaken. Regions selected were; Northland, Taranaki, Canterbury and Southland. The model predicted 92-129% of per cow milk production and, while it followed observed pasture growth patterns, there was a tendency to over-predict annual growth (5-57%) especially during spring-early summer and more notably in the Northland region. Annual pasture growth in Southland was consistently under-predicted by approximately 20%. This variation is likely due in part to differences in pasture species, soil types and the method of collecting pasture data, influencing how well the model predicted growth. Using specific climate data and management information, the model successfully predicted dairy production in most regions of New Zealand.

JA, Lile, KP Bright, CC Palliser, WE Prewer, and ME Wastney

Proceedings of the New Zealand Society of Animal Production, Volume 62, Palmerston North, 7-11, 2002