Simulated effect on dairy cow and herd production of different grazing intensities

Abstract

The effect on cow and herd level of different grazing intensities was evaluated using results from short term grazing experiments combined with different dairy herd management strategies from twelve commercial herds using a dynamic stochastic model (SIMHERD) for the simulation of dairy herd production and a deterministic model (SIMCOW) for the simulation of cow production. High grazing intensity had a negative effect on milk production and live weight gain on cow level in all twelve herds, but the energy efficiency and the distribution between milk production and live weight gain varies between herds. The same general effects were simulated on herd level, but there was no direct connection between the results on cow level and on herd level on the production in the grazing period of different intensity. The annual results of different grazing intensities showed a positive carry-over effect on milk production of decreased grazing intensity but a negative effect on live weight gain.