Effect of diet composition on maturation rate of female Atlantic salmon (Salmo salar) during gonadal maturation

Abstract

The influence of different diet formulations during gonadal maturation on reproductive efficiency and embryo quality in Atlantic salmon was investigated. Four diets were compared: Diet 1 contained exclusively marine-origin protein and lipid ingredients, Diet 2 involved substituting 65% of the protein and 51% of the lipid by terrestrial animal and vegetable sources, Diets 3 and 4 were commercial diets. The results showed a higher number of spawned females in the groups of fish fed with diets 1 (73.3%) and 2 (66.7%) than those fed with diets 3 (53.3%) and 4 (50%). Spawning weight and total fecundity did not differ between diets, but a strong correlation was found between these variables, independent of diet. There were no significant differences in zootechnical parameters, but the groups of fish fed the commercial diets tended to have greater weight and length. Oocyte diameter did not differ, but percent hydration was statistically different between groups fed diets 2 and 3. Although there was no difference in embryonic malformations between diets, the presence of microphthalmia correlated negatively with oocyte diameter and percent hydration in embryos obtained from the group of fish fed with Diet 3. Blastomere symmetry and survival at 280 ATU showed statistical differences between diets 3 and 4. Using high-nutritional-value marine ingredients (Diet 1) during gonadal maturation improves reproductive performance in female Atlantic salmon. Enhancing fish broodstock nutrition through targeted research can optimize reproductive success, increase yields, and promote sustainable aquaculture practices.