Author(s)

Ryan Page, Charles Rosenkrans Jr.^*

Department of Animal Science, Division of Agriculture, University of Arkansas System, Fayetteville, AR, USA.

Our purpose was to determine the impact of ascorbic acid and α-tocopherol on bovine sperm motility following short-term storage or cryopreservation. Semen was collected from mature Angus bulls (n = 4). The experimental design was a randomized complete block, with bull serving as block, and treatments were structured as a 4 × 4 factorial with four concentrations of ascorbic acid (0, 5, 10, 20 mM) and four concentrations of α-tocopherol (0, 0.05, 0.5, 5 mM). Sperm motility characteristics were evaluated using computer assisted sperm analyses at 0, 4, and 8 h of incubation (39˚C) and post-cryopreservation. Initial sperm motility was (79.6% ± 1.6) and decreased to (6.1% ± 1.6%) after cryopreservation. Cryopreserved spermatozoa had lower (P < 0.05) post-thaw qualities when compared with fresh collections and for spermatozoa that had been incubated for 4 h at 39˚C. In contrast, most of the motility characteristics of spermatozoa that were incubated for 8 h at 39˚C were similar to those of post-thaw spermatozoa. Sperm motility, hyperactivity, and velocity characteristics were not affected (P > 0.1) by α-tocopherol. Addition of 20 mM ascorbic acid to storage media decreased (P < 0.05) sperm velocity traits, but the addition of 5 or 10 mM ascorbic acid did not alter sperm velocity. Sperm cell oxidation following cryopreservation/post-thaw was affected by an interaction (P < 0.05) between concentrations of ascorbic acid and α-tocopherol. Stepwise regression models predicted (P < 0.05) post-thaw motility and velocity characteristics of cryopreserved spermatozoa. Our results suggest that adding ascorbic acid and α-tocopherol was not beneficial for short-term storage of spermatozoa; however, our results were inconclusive with regards to inclusion of ascorbic acid and α-tocopherol in egg yolk-based cryopreservation media.

Bull Spermatozoa, Antioxidants, Cryopreservation

Page, R. and Jr., C. (2019) Bovine Sperm Motility as Affected by Alpha Tocopherol and Ascorbic Acid during Storage. Advances in Reproductive Sciences, 7, 39-49. doi: 10.4236/arsci.2019.72006.