The influence of L‐proline and fulvic acid on oxidative stress and semen quality of buffalo bull semen following cryopreservation

BACKGROUND: This study investigates the effects of cryopreservation and supplementation of Azeri water buffalo's semen with proline (Lp) and fulvic acid (FA). OBJECTIVES: Therefore, this study aimed to assess motility parameters, sperm viability, oxidative stress parameters, and DNA damage to detect the optimum concentrations of Lp and FA for buffalo semen cryopreservation. METHODS: Thirty semen samples of three buffalo bulls were diluted in Tris‐egg yolk extender and divided into 12 equal groups including control (C), Lp‐10, Lp‐20, Lp‐40, Lp‐60, Lp‐80 (containing 10, 20, 40, 60, 80 mM L‐proline, respectively), FA‐0.2, FA‐0.5, FA‐0.8, FA‐1.1, FA‐1.4 and FA‐1.7 (containing 0.2%, 0.5%, 0.8%, 1.1%, 1.4% and 1.7% fulvic acid, respectively). RESULTS: The velocity parameters, TM and PM were improved by FA‐1.7, FA‐1.4, Lp‐40 and Lp‐60 groups compared to the C group but no significant difference was found regarding the amplitude of lateral head displacement and straightness compared to the control groups. The percentage of sperm viability and PMF were increased by FA‐1.7, FA‐1.4, FA‐1.1, Lp‐40 and Lp‐60 groups compared to C group, while in terms of sperm DNA damage FA‐1.7, FA‐1.4, FA‐1.1, Lp‐10, Lp‐20, Lp‐40 and Lp‐60 groups showed better results compared to C group. The results also showed that FA‐1.7, FA‐1.4, FA‐1.1, Lp‐20, Lp‐40 and Lp‐60 groups could improve TAC, SOD, GSH and decrease MDA levels. Also, FA‐1.7, FA‐1.4, Lp‐20 and Lp‐40 groups could improve GPx levels but just FA‐1.7, and Lp‐40 groups could improve CAT levels compared to C group. CONCLUSIONS: Thus, it can be concluded that L‐proline and fulvic acid supplementations can improve the quality parameters of post‐thawed buffalo bull semen.