Efeito do uso de minerais traços e vitaminas A e E na saúde de vacas holandesas no período de transição

Abstract

The transition period is the most critical dairy cows health because it causes great impact on the metabolism, immunity and production of these animals. Some microminerals and vitamins can improve the immune response of production animals against diseases and to stressful situations. Therefore, the aim of this study was to evaluate the parenteral application of trace minerals and vitamins A and E the energy profile and oxidative stress of Holstein cows in transition period. Sixty animals were divided into two groups: supplemented with trace minerals and vitamins (GMTV) (n = 30) and control (CG) (n = 30). Mineral and vitamin supplementation was carried out through subcutaneously with 5 mll of the product containing 10 mg/ml copper (as edetate), 40 mg/ml zinc (as edetate), 10 mg/ml manganese (as edetate) and 5 mg/ml selenium (as sodium selenite) and 5 ml of the product containing 35 mg/ml vitamin A (as palmitate) and 50 mg/ml vitamin E (as acetate). Blood samples were collected 21 days prepartum, 14 prepartum, 7 days prepartum, 7 days postpartum, 14 days postpartum and 21 days postpartum. In the first study the objective was to evaluate oxidative stress parameters and neutrophilic function in Holstein females in the transition period. A significant difference was observed between treatment X days for SOD values, with a higher activity of this enzyme in GMTV females, in weeks close to calving. Significant day difference and treatment X day were observed for TBARS, in which GMTV females showed lower TBARS values at all times except seven days postpartum. There was a significant day effect for leukocytes, treatment X day for neutrophils, and for neutrophilic phagocytosis, which the GMTV females had leukocytes and neutrophils values lower close to parturition, besides to greater neutrophilic phagocytosis. In the second study the objective was to evaluate the supplementation effect on biochemical and hormonal parameters in Holstein cows in the transition period. The differences observed were only related to the time and not to the treatment.. The AGNES values were higher on the parturition day, and the BHBA had increasing values after calving, peaking in the third week of lactation. The fructosamine presented increasing values until the parturition day, with higher concentrations at experimental moment. Higher HDL levels were detected 21 days postpartum. The triglycerides values remained high in the prepartum period, but showed a sudden reduction on the parturition day, maintaining lower values postpartum. Both calcium and IGF-1 concentrations were lower on parturition day. In addition insulin and cortisol values were higher on the parturition day. In conclusion, moderate milk production animals submitted to adequate diets present little response to the use of certain microminerals and vitamins, but it can be noticed an improvement in SOD activity and neutrophilic activity in GMTV animals. This enhances the binding of trace minerals and vitamins to dairy cows immune system, especially in the transitional period, which is linked to impaired immune response.