An attempt is made to establish a relationship between herbage utilization, pasture production, and animal performance per unit area. When pastures are rotationally grazed, it appears that the highest pasture yield and animal production per unit area will result only if feed demand is closely matched with supply so that little stubble is left after grazing. Experimental data indicate that the aim should be to achieve at least 60% single grazing utilization of the total herbage on offer as long as in so doing overgrazing does not occur. Future work is likely to show the need for an even greater degree of utilization if per-hectare production is to be maximized. Limited data suggest that overgrazing of ryegrass pastures commences when they are grazed below 2 cm, while with more upright grass species this starts when defoliation is closer than 10 cm.