Effects of omega-3 supplementation on boar sperm quality

Introduction:

As artificial insemination is largely used in swine, strategies to optimize sperm quality are of interest, since boar sperm is sensitive to damages due to cold shock and oxidative stress (2). Supplementation of diets with polyunsaturated fatty acids of the omega-3 series appear to benefit female reproductive performance, but their effects on boar sperm quality are not yet clarified. This study evaluated the effects of omega-3 supplementation in diets on boar sperm quality.

Materials and Methods:

Six crossbred adult boars with known fertility were used. The boars were split in two groups (n = 3 each): a control that were fed 2.8 kg/d of a diet including 16.0% CP and 3,200 kcal ME/kg; and a group that received the same diet supplemented with 150 g/kg of seaweed meal derived from the microalgae Schizochytium sp (4), containing 120 g of docosahexaenoic acid (DHA) per kg, totaling 18% DHA, during 75 d.

Sixteen semen samples were collected per boar, from 7 d after the beginning of the supplementation, until 60 d after its conclusion. Semen was diluted in BTS (3), with 3 x 10⁹ spermatozoa in 100 mL. Sperm motion parameters were determined by a computer-assisted semen analyses system (SpermVision®, Minitube), using 6 automated randomized fields and compared between groups using ANOVA with repeated measures. Responses were transformed to arcsine or log when lack of normality was detected.

Results:

For omega-3 supplemented boars, distance average path (in both a curved and in a straight line), velocity average path (in both a curved and in a straight line), amplitude of lateral head displacement and beat cross frequency were lower than for the control group (P < 0.05). No differences (P > 0.05) were observed for total and progressive motility, straightness, linearity, wobble and beat cross frequency.

Conclusion:

Compared to the control, spermatozoa produced by omega-3 supplemented boars presented similar motility, but were slower and traveled lower distances. Generally, studies dealing with omega-3 effects on boar sperm quality revealed contradictory results. Beneficial effects were reported (5, 6), as well as potential toxicity (6) and lack of effects on sperm quality (1). Further studies in this field are still required.

Disclosure of Interest: None Declared.

Published in the proceedings of the International Pig Veterinary Society Congress – IPVS2016. For information on the event, past and future editions, check out https://www.theipvs.com/future-congresses/.