Impacto de alterações de ECC no metabolismo e no índice de ECC de vacas leiteiras mestiças pós-parto.

O escore de condicao corporal (ECC) e uma variavel categorica que e amplamente aceita como uma importante ferramenta para quantificar subjetivamente as reservas de energia em vacas de leite. Os objetivos desse estudo foram avaliar o efeito da perda de ECC pos-parto no indice de ECC e no metabolismo e usar o iECC para avaliar impacto de mudancas no manejo nutricional em vacas de leite. No Experimento 1 foram incluidos dados de lactacao de 35 vacas Girolando (Holandes x Gir). No dia do parto e a cada 15 dias ate os 90 dias em lactacao (DEL), as vacas foram avaliadas quanto ao ECC, peso-vivo, ângulo da garupa (AIG), producao de leite e concentracao serica de beta hidroxi-butirato (sHBO). As vacas foram divididas em 2 grupos de acordo com a perda de escore de ECC do parto ate 90 DEL: 1) Vacas que perderam 0,5 ECC (n=14). Vacas que perderam pouco ECC demonstraram menor variacao do ECC no periodo pos-parto recente (P 0,5 ECC (n=14). Less variation range of BCS was observed in cows that loss less BCS (P < 0.001). Moreover, cows that loss less BCS had higher BCSi (P < 0.001). In contrast, cows that loss greater BCS had higher IAR (P < 0,001) and higher serum sHBO (P = 0,01). No difference between groups was detected in milk yield (P = 0.9). The Experiment 2 was a non-randomized controlled trial, in which the BCSi of the herd was evaluated before and after a strategical change in the nutritional plane. The change was an adjustment in the ration supplementation according to the milk yield and the adjusted difference of BCS of each cow. Sixteen crossbred Girolando (Gyr x Holstein) cows were enrolled in this study. The BCSi of the cows were evaluate in two distinct moments: before (Control group) and after the change in the nutritional plane (ECC group). The ECC group had higher BCSi (75.3%; good level; P=0.02) than Control Group 59.5% (fair level). Altogether, these results demonstrated that cows that calved in adequate BCS had better metabolism profile and had greater BCSi in the postpartum period in comparison to cows that calved with greater BCS. Moreover, it was possible to observe changes in the BCSi when specific changes in the nutritional plane were performed.