Palmitoleate enhances quality of rooster semen during chilled storage

The practice of artificial insemination is widely utilized in poultry; and this requires a broad use of semen storage techniques to prevent the reduction of fertilizing ability of stored semen. The antioxidant activity of palmitoleic acid with in vitro experiments has been shown. The present study was designed to evaluate the effect of palmitoleic acid on the quality of rooster semen stored at 4C. Semen was collected from ten roosters twice a week. Ejaculates with greater than 80% forward spermatozoa motility were pooled and after dilution semen was enriched with 0 (control), 0.125 (P 0.125), 0.25 (P 0.25), 0.5 (P 0.5) and 1 (P 1) millimolar palmitoleate. Forward spermatozoa progressive motility and viability, as well as amounts of malondialdehyde (MDA) and total antioxidant activity (AOA) were evaluated in seminal plasma and spermatozoa at 0, 24 and 48h of storage. Motility was 78.5±2.21, 77.5±1.04, and 69.5±2.32% at 24h and 58.66±1.35, 49.33±1.36 and 43.00±2.08% at 48h in P 0.125, P 0.25 and control, respectively (P<0.02). There were no significant differences in amount of MDA in the seminal plasma among groups, while the amounts of MDA in spermatozoa were less in the P 0.125, P 0.25 and P 0.5 groups compared to the control group at 24 and 48h of storage (P<0.002). Total amounts of AOA in seminal plasma were greater in palmitoleate treatment groups than the control at 24 and 48h (P<0.01). Moreover, palmitoleate treatment groups had greater values of total AOA in spermatozoa compared to the control group at 24 and 48h of storage (P<0.05). In conclusion, enrichment of rooster semen with small doses of palmitoleate has beneficial effects on the semen quality during cold storage.