Pycnogenol® supplementation improved the erythrocyte stability of packed donkeys during the late hot-dry season in Zaria, Nigeria

The aim of this study was to determine the effect of pycnogenol® (PYC) on erythrocyte stability of donkeys subjected to packing during the late hot-dry season. Ten donkeys, divided into two groups, served as experimental subjects. P-PYC group (n = 5) was subjected to packing only, while P+PYC group (n = 5) was administered with PYC (10 mg/kg) and subjected to packing. Erythrocytes obtained from each animal in the experimental groups were added into saline solution of different concentrations (0.9, 0.6, 0.4. 0.2, and 0.0 g/100 ml). Erythrocyte osmotic fragility index (EOFI) was evaluated spectrophotometrically. The concentration of isoprostane was also determined. The mean EOFI was significantly (P < 0.05) higher in P-PYC group 3 and 7 days after packing at 0.6 g/100 ml, with values of 32.4 ± 3.2 and 53.4 ± 4.3%, respectively. However, there was no significant (P > 0.05) difference in the MCF recorded in both groups, before, after, 3, and 7 days after packing. Percentage erythrocyte stability was significantly higher (P < 0.05) in P+PYC group, especially during, and 7 days after packing with values of 24.3 ± 9.2 and − 23.3 ± 22.8%, respectively when compared with the values of 8.6 ± 3.3 and − 79.7 ± 9.3% obtained in P-PYC group, respectively. Mean isoprostane concentration was significantly (P < 0.05) higher in P-PYC group when compared with the value in P+PYC group, 7 days after packing. In conclusion, environmental and packing stresses decreased stability of the erythrocytes in donkeys; however, PYC may have played an ameliorative role.