Standardization of manual technique for obtaining platelet-rich plasma in cattle

For standardization of manual technique to obtain autologous platelet-rich plasma (PRP) in cattle with reduced cost (manual method) and good quality (ability to concentrate platelets, high level of growth factors and reduced contamination with leukocytes and erythrocytes), that may be used as a modulating agent of the immune response of cows chronically infected with various diseases, 450ml of whole blood from nine clinically and hematologically healthy cattle were collected in CPDA-1 bags and processed within four hours after collection. The blood was divided in aliquots to evaluate 8 protocols (P) of double centrifugation which varied as the speed and time of centrifugation. Platelet, erythrocytes and leukocytes counts in PRP were performed by manual method in a Neubauer chamber. The highest concentration of platelets was obtained in P5 (400g and 800g both for 10 min), followed by (p > 0.05) P3 (120g e 473g ambos durante 10 min), P4 (300g e 640g durante 10 min cada), P6 (640g durante 10 min e 640g durante 5 min), P8 (640g durante 5 min e 120g durante 10 min) and P7 (720g and 720g both for 5 min) and different (p < 0.05) than the protocols that had lower rates at P1 (120g to 240g, both for 5 minutes) and P2 (both 120g and 473g for 5 min). As for erythrocytes, P8, P7, P6, P5, P4 showed lower concentrations with higher values (p < 0.05) observed in P3 and P2. Lesser values of leukocytes were found in P5, P6, P7 and P8 with the biggest value (p < 0.05) obtained in P2. All protocols (P1 to P8) were efficient to concentrate platelets and the lowest value (3.65 +/- 0.79) was found in P1. Regarding TGF-beta 1, the P1 and P8 protocols demonstrated the highest values. According to results, P5 and P8 protocols showed the best results for production of PRP in bovine.