EFFECTS OF FEEDING STRATEGY ON GROWTH OF SEA BREAM (SPARUS AURATA L.) DURING WINTER–SPRING AND POSSIBLE IMPLICATIONS FOR »WINTER DISEASE« SYNDROME

Abstract

The influence of different feeding strategies on growth and incidence of winter disease syndrome in sea bream (Sparus aurata L.) was followed during winter–spring period. Fish were fed either extruded (48.9% protein, 14.2% lipid, group A) or compressed (53.5% protein, 10.3% lipid, group B) pellet from March to June. Two groups (A1 and B1) were deprived of food for two months (mid March to mid May) and thereafter refed until June. The weight gain of fish from groups A and A1 in June were 6% and 5%, respectively. For the group B the statistically insignificant (p<0.05) weight increase of 1% was recorded in June compared to the value of March. In the same period fish of group B1 exhibited significant (p<0.05) decrease in weight of 16.2%. The same group displayed the smallest condition index of 1.38 and hepatosomatic index of 1.28 after two months of starvation. The relative content of most amino acids in the whole body of fish from all groups showed only minor variations during the study. Decrease of the total amino acid content was recorded for fish of groups B and B1. Slight decrease in relative content of saturated and monounsaturated fatty acids was recorded for all groups in May compared to the values of March, whereas the content of polyunsaturates increased in all groups in the same period. Starvation did not influence the relative content of fatty acids in sea bream. Total mortality caused by »winter disease« syndrome for fish of groups A and B was 4.2% and 6.3%. Groups A1 and B1 exhibited mortality of 0.9% and 1.0%, respectively.

Keywords

• amino acids
• fatty acids
• growth
• sea bream (sparus aurata)
• starvation
• winter disease syndrome