AbstractBetween 1967 and 1975, 416 beef animals were grazed rotationally on an indigenous pasture (11.65 ha) containingFestuca rubra, Holcus lanatus, Poa trivialisandAgrostisspp. and dicotyledonous plants, but littleLolium perenneorTrifolium repens. Part of the land received fertilizer nitrogen at rates varying between 120 and 200 kg h−1each year and part did not; some of the land was grazed only and some was cut and then grazed.The winter gains of the animals (approx. 45 kg) were more variable and less than the summer gains (approx. 155 kg). Summer gain was inversely correlated with winter gain. An increase in initial weight of animals purchased from 1973 onwards did not increase either winter or summer gain. Friesians gained more than Hereford‐cross animals during the winter, but there was no difference in summer gain.During 9 years the average animal weight per grazed ha in April was increased from 1260 to 2122 kg. The mean total gain on 1165 ha of grass was 6486 kg per annum in the first 3 years and 7266 kg per annum in the last 3 years. The average annual production was 590 kg live‐weight gain and 1.01 t hay or 2.33 t silage per ha. The output of fertilized grass in 1975 was calculated as 842 Livestock Unit Grazing Days (LUGD) per ha and that from unfertilized grass as 360 LUGD per ha. The overall output of utilized metabolizable energy in 1975 was 59–7 GJ h−1, with 69.3 GJ h−1from fertilized grass and 29.8 GJ h−1from unfer