The aim of this work was to study the influence of calving seasons (spring and autumn), upon growth rate of Ibagé x Hereford crosses (F1) under natural pasture grazing conditions, at the Centro de Pesquisa de Pecuária dos Campos Sulbrasileiros, of Empresa Brasileira de Pesquisa Agropecuária, in Bagé, Rio Grande do Sul state, Brazil. Seventy four animals (44 born in spring and 30 in autumn) were used, weighed at 90 days intervals from birth up to the age of 1080 days. The highest body weights were observed for animals born in autumn at birth, 360, 630, 720 and 1080 (P <0.01) and, at 990 days of age (P <0.05), while the animals born in spring were heavier at the ages of 180, 540 and 900 (P <0.01) and, 450 and 810 days (P <0.05).
natural grassland; beef cattle
