Timeline of fatty acid incorporation from diet to egg in California yellowtail Seriola dorsalis

Existing broodstock research has ascertained that eggs are heavily influenced by broodstock diet, but there is currently sparse information regarding the time it takes for nutrients to transfer into eggs after broodstock feeding. Thus, our study aimed to quantify this duration of broodstock to egg nutrient transfer by feeding two alternating diets. In 2021, nine California yellowtail (Seriola dorsalis) broodstock were fed alternating diets of commercial pellets (Vitalis Prima: Skretting, Norway) and cutbait (70% sardine and 30% squid). These diets were switched every 41 days and then repeated so each diet was provided twice during the study. Biochemical and biometric data from spawns were collected and statistically analyzed by grouping spawns based on diet type and diet duration. Between diet switches, we observed a selective retention of C18:3n-3 (α-linolenic acid) and C18:2n-6 (linoleic acid) from the Vitalis diet, and C20:5n-3 (eicosapentaenoic acid), from the cutbait diet. Our results showed overall fatty acids from both diets were incorporated by the eggs after 10 to 19 days of feeding. Knowing this timing of nutritional incorporation from broodstock diet to eggs will help significantly improve feed efficiency by providing producers with a specific timeframe to maximize egg quality through dietary modifications or supplements.