The use of cooled and frozen/thawed semen offers many advantages to breeders.
However, many stallions produce spermatozoa that are unable to endure the stresses of
cooling/storage and freezing/thawing. Improving the quality and viability of equine
spermatozoa via appropriate dietary manipulation could make these stallions
commercially viable for cooling or cryopreservation. To evaluate whether spermatozoa
quality and viability can be improved by supplementation of omega-3 fatty acids, and if
improvements can be made by altering the sources of these fats, nine miniature stallions
were placed into 1 of 2 treatment groups and fed either a fish- or algae/flaxseed-based
supplement which was added to the basal concentrate. Motion characteristics, membrane
integrity and morphology of spermatozoa in fresh, cooled/stored (24 and 48 h), and
frozen/thawed semen samples were analyzed. When comparing spermatozoa obtained
from stallions in each treatment, no differences were found (P > 0.05) in motility,
percentage of membrane intact spermatozoa, and percentage of morphologically normal
spermatozoa of stallions. Overall, omega-3 supplementation did not appear to have a
beneficial effect on offsetting the harmful effects of the cooling and freezing processes. However, when analyzing the data of one stallion that had < 40% progressive motility
(PMOT) after 24 h of cooling and storage, a significant increase was observed in total
motility, and progressive motility of fresh and 24 h cooled/stored spermatozoa was
observed when supplemented with the fish-based supplement. Thus, omega-3 fatty acid
supplementation may be most beneficial for stallions that produce lower quality
ejaculates. However, further studies should be conducted, with a larger sample size, in
order to substantiate these findings
