N-3 Long-chain polyunsaturated fatty acids improve the sperm, egg, and offspring quality of Siberian sturgeon (Acipenser baerii)

Abstract

Two diets with the same docosahexaenoic acid:eicosapentaenoic acid ratio (1.8:1), but with different n-3 long-chain polyunsaturated fatty acid (n-3 LC-PUFA) contents [29.5g/kg (DH) and 17.9g/kg (DL)], were designed and fed to two groups of 46 female and 30 male Siberian sturgeon (Acipenser baerii) broodstock for 11months. Sperm and egg quality and reproductive performance indices were recorded during cross-breeding. Larval offspring resulting from cross-matings were divided into the following four groups for a 30-d feeding trial: D1 (DH♀×DH♂), D2 (DH♀×DL♂), D3 (DL♀×DH♂), and D4 (DL♀×DL♂). The results showed that egg size of the DH group was significantly larger than that of the DL group. With respect to sperm quality, there were no significant differences in wobble, amplitude of lateral head displacement, beat/cross frequency, and mean angular displacement between the two dietary groups; however, a high n-3 LC-PUFA diet increased sperm curvilinear, straight-line, and average path velocities in the DH group. The DH group had significantly lower levels of serum triglyceride, low-density lipoprotein cholesterol, and malonaldehyde, but higher superoxide dismutase level, and total antioxidant capacity compared with the DL group. At 7 and 32days post hatching, the survival of larvae in groups D1 and D2 was significantly higher than that in groups D3 and D4. The specific growth rate of larvae in group D4 was the lowest among the four groups. The results suggest that n-3 LC-PUFA can improve the reproductive performance of male and female broodstock of Siberian sturgeon and the quality of their offspring, but that n-3 LC-PUFA enrichment of the diet is more critical for female broodstock than for males.