This trial evaluated the effects of different levels of supplementation onthe growth of weaned female beef calves grazing native pasture during the fall.Development of these same animals grazing pastures of black oat (Avena strigosaSchreb) and annual ryegrass (Lolium multiflorum Lam) during the winterwere also investigated. One hundred-eighteen female calves averaging seven monthsof age from three distinct herds: H1 and H2 (Aberdeen Angus animals) and H3(crossbred Aberdeen Angus animals) were used. Calves grazing the native pasturewere supplemented with a commercial concentrate as follows: 0.7, 1.0 or 1.3%of body weight (BW). During the winter, animals were moved to pastures of blackoat and annual ryegrass and were all maintained in the same group. The followingmeasurements were taken: BW, body condition (BC), average daily gain (ADG),body condition gain (BCG), and relative growth (RG). No significant supplementationlevels ´ herd interactions were detected. Animals grazing native pasturesupplemented with 1.3% BW as concentrate had greater ADG (0.405 kg) than thosesupplemented with 0.7% BW (0.300 kg). The ADG of animals grazing black oat andannual ryegrass did not differ and averaged 0.820 kg. Within the three herds,animals from H3 had greater BW and BC than those from H1 and H2. Calves fromH1 with lower initial BW and BC showed compensatory growth and had similar BWand BC compared to H2 calves at the end of the winter period. H1 calves hadhigher RG (77.1% of BW and 32.4% of BC) than H2 and H3 calves, which averaged57.1% of BW and 14.7% of BC. Initial BW and BC were highly correlated (r=0.811)but both were not correlated with ADG during rearing. The final BW and BC wereaffected by initial BW and ADG during rearing. Calves with the greatest BW atweaning were not always the heaviest animals at one year of age.
