Hereford x Friesian (HF) and Limousin x Friesian (LF) heifers purchased at two weeks of age were artificially reared under the same conditions. They were first bred to calve at two years using one Aberdeen-Angus bull. One Simmental sire was used for the second and fourth calvings and one Charolais sire was used for the third calving. Data are presented for the cow herd up to the date of fifth calving and on their progeny to weaning for each of the first four calving seasons. Calving was in the period March/June. Animals were put to pasture in April. Weaning was in October/November when all animals were housed. Cows were fed grass silage in winter. Information was available for 36, 35, 27 and 24 calvings in seasons 1, 2, 3 and 4 respectively. The corresponding figures for calves available at weaning were 26, 35, 25 and 22.