Docosahexaenoic acid associated vitamin E in the diluent for cryopreservation of goat semen

Abstract

The objective of this study was to evaluate the effect of and determine the optimum level of inclusion of docosahexaenoic acid (DHA) in the diluent for goat semen cryopreservation. Five Boer males underwent semen collection, totaling 10 viable collections per animal. After evaluation, the ejaculates were pooled and fractionated in Tris-yolk medium with the addition of 0; 30; 45; or 60ng mL-1 of DHA and 0.4 mmol of alpha-tocopherol (Vitamin E). The semen was cryopreserved in a freezing machine (TK 3000TM) and placed in a cryogenic cylinder for subsequent analysis. Data were evaluated by regression analysis at 5% significance. There were no differences (P > 0.05) in sperm kinetic parameters evaluated by computer assisted sperm analysis: total motility (79.17 ± 17.31%), progressive motility (14.04 ± 5.73%), curvilinear speed (58.82 ± 6.35µm/s), progressive linear speed (22.49 ± 3.63µm/s), mean path speed (35.17 ± 4.52µm/s), linearity (38.69 ± 5.79%), rectilinearity (63.99 ± 6.64%), and oscillation index (59.68 ± 2.99%). There were no differences (P > 0.05) found from the membrane functional integrity test for reactive spermatozoa (69.66 ± 9.76%), plasma and acrosomal membrane integrity of intact spermatozoa (29.86 ± 7.57%), mitochondrial potential of Class I cryopreserved goat semen (72.75 ± 9.81%), and chromatin compaction of intact chromatin (96.87 ± 4.37%). Thus, the inclusion of up to 60ng mL-1 of DHA did not promote any improvement in the seminal quality parameters of post-thawed goat semen.