Efeitos da suplementação sobre desempenho e características nutricionais e metabólicas de vacas e bezerros de corte a pasto

For the thesis composition were prepared three scientific articles based on studies with dams of Nellore breed and their respective calves, submitted to different supplementation schedules in different phases of production. In the first article the objective was to evaluate the effect of Bos indicus dams’ supplementation in the pre and/or post calving period, on the performance of their male and female calves in the suckling phase. Eighty four pluriparous Nellore cows (body weight (BW) of 522 ± 9 kg and body condition score (BCS) of 5 ± 0.08 (1-9 scale)) and their calves (44 females and 40 males) were used. The dams’ treatments were: 1 kg of supplement during 90 days before and 90 days after calving (Supplemented all time), 1 kg of supplement during 90 days before calving and mineral mixture after calving (Supplemented before calving), mineral mixture before calving and 1 kg of supplement during 90 days after calving (Supplemented after calving) and a control treatment, receiving only mineral mixture ad libitum during entire experiment (Control). Cows supplemented before calving, calved heavier calves than supplemented after calving group. No differences were observed in BW at weaning, cows’ BCS and cow’s milk production (P > 0.05). Dams from the Control treatment had smaller milk fat in the first milk collection in the calves’ supplementation period, when contrasted with the supplemented groups (P 0.05) in the first evaluated period. Calves from 10S/5S treatment spent more time suckling and less time eating supplements (P 0.05). Matrizes do tratamento controle apresentaram menor teor de gordura no leite na primeira coleta, em relação às suplementadas (P 0.05) em ECC, PC final e GMD das matrizes durante o período de avaliação. Bezerros do tratamento MM passaram mais tempo (P 0.05) entre os bezerros de diferentes tratamentos, no primeiro período. Bezerros do tratamento 10S/5S passaram mais tempo (P > 0.05) mamando e menos tempo (P > 0.05) consumindo suplemento que os do tratamento 5S/10S, no segundo período. Mães de bezerros do tratamento MM apresentaram maior tempo de ócio e menor tempo de pastejo (P > 0.05), quando comparadas às mães de bezerros dos tratamentos 5S/10S e 10S/5S. Neste estudo foi concluído que diferentes esquemas de suplementação de bezerros a pasto, não afetam o desempenho de suas mães e que a suplementação diminui o tempo de pastejo destes bezerros.Conselho Nacional de Desenvolvimento Científico e Tecnológic