South African Journal of Animal Science
On-line version ISSN 2221-4062
TEIXEIRA, S.M.P.; CHAVEIRO, A. and MOREIRA DA SILVA, F.. The effects of three extenders on refrigerated boar semen. S. Afr. j. anim. sci. [online]. 2015, vol.45, n.1, pp. 82-88. ISSN 2221-4062. http://dx.doi.org/10.4314/sajas.v45i1.10.
This study aims to evaluate the quality of boar sperm that was refrigerated for 14 days at 17 °C with three extenders. For this study, samples from four boars were collected twice a week using the gloved-hand technique. After collection, only ejaculates showing total motility of 75% or greater were submitted to the refrigeration process. Ejaculates were diluted in Androhep, MR-A® or Reading. Each portion was kept for two hours at 22 °C, then sperm motility was assessed through contrast microscopy. Sperm mitochondrial activity, viability and acrosome integrity were measured by the flow cytometric technique. The remaining diluted semen was maintained at 17 °C for 336 h, and the same analysis being repeated every 48 h. Semen diluted in Androhep revealed no significant quality deterioration in percentage of live spermatozoa during refrigeration. However, after 144 h, viability decreased significantly for MR-A® and Reading (63.3% ± 7.0 and 66.4% ± 6.2, respectively), and after 336 h, this decrease was accentuated (56.3% ± 3.9 and 18.4% ± 6.2, respectively, for MR-A® and Reading). On average, for all three extenders, acrosome integrity values did not differ statistically up to 144 h, ranging from 48.3 ± 2.3 for MR-A® to 62.4 ± 3.2 for Androhep. Then values decreased towards the end of the experiment, with Androhep always presented the higher values, while Reading resulted in the lowest values (46.3 ± 3.2 and 5.6 ± 1.4, respectively). No significant changes in mitochondrial membrane potential were observed during the refrigeration period. Results of this study indicate that Androhep achieves the best results for the various parameters studied over time.
Keywords : Boar; flow cytometry; long-term extenders; refrigeration; semen.