The effect of protein and n-3HUFA on the reproduction of turbot (Scophthalmus maximus)

This study is conducted to test the effect of nutrition of diets on the reproduction of turbot Scophthalmus maximus. The results show that high content of protein and high level of n-3HUFA are very important for turbot broodstock. Four groups of turbot broodstocks are fed with different formulated feeds for 5 months. It is obvious that the broodstock of turbot has a higher growth rate when fed with diets containing more protein and n-3HUFA. The fatty acid of spawned eggs is greatly affected by the diets of broodstock. The eggs have higher content of n-3HUFA if more n-3HUFA diets are fed. The eggs production, buoyant rate and hatching rate are higher when the broodstocks are fed with higher protein and n-3HUFA diets. As a result, the viability of turbot larvae is high. Feeding broodstock with compound feed, protein percentage of which is 49.3%, lipid percentage is 14.6% and its ∑n-3HUFA rate is 29.3%, we get a result that the mean fecundity of experiment broodstock is 1.45×10 6, mean egg size is 1.053 mm, the rate ∑n-3HUFA in lipid is 20.38%, the rate of floating egg is 95%, and the turbot fry survival rate is 23% after 30days′ seed breeding. This result is obviously better than that obtained from the experiment group of low protein percentage and low percentage of ∑n-3HUFA. We can conclude that the protein percentage should be≥45%, lipid percentage should be≥10% and its ∑n-3HUFA rate shoule be≥20%. Compound feed with high percentage protein and n-3HUFA is very important for broodstock reproduction.