SIMULATED EFFECT ON DAIRY-COW AND HERD PRODUCTION OF DIFFERENT GRAZING INTENSITIES

The effect on cow and herd level of different grazing intensities was evaluated using results from short term grazing experiments combined w ith different dairy herd management strategies from twelve commercial herds using a dynamic stochastic model (SIMHERD) for the simulation of dairy held production and a deterministic model (SIMCOW) for the simu lation of cow production. High grazing intensity had a negative effect on milk production and live weight gain on cow level in all twelve he rds, hut the energy efficiency and the distribution between milk produ ction and live weight gain varies between herds. The same general effe cts were simulated on herd level, but there was no direct connection b etween the results on cow level and on herd level on the production in the grazing period of different intensity. The annual results of diff erent grazing intensities showed a positive carry-over effect on milk production of decreased grazing intensity but a negative effect on liv e weight gain. (C) 1997 Published by Elsevier Science Ltd.