The integration of conservation with grazing for milk production: a computer simulation of the practical and economic implications

Earlier studies have concluded that for a dairy enterprise the most profitable conservation strategy, where cutting and grazing areas are separate, is generally associated with relatively low-digestibility silage. The aim of this study has been to investigate whether this conclusion remains true where cutting and grazing are integrated. A mathematical model of grass production and utilization by a dairy enterprise has been developed from information collected from a variety of experimental sources. It was found that cutting strategies aimed at making low-digestibility silage could not automatically be regarded as the most profitable. In good grass-growing conditions strategies resulting in low-digestibility silage did appear to offer the highest gross margins per unit area, but under average and poor growth conditions the greatest profits were associated with high-digestibility silage strategies. In particular, it was noted that the timing and frequency of conservation cuts influenced the efficiency with which grass could be utilized on the grazing areas and this fact rather than yield of conserved material influenced the comparative biological and economic efficiency of the different cutting strategies.