Suitable Levels of n-3 Highly Unsaturated Fatty Acids in Diet for Fingerlings of Red Sea Bream.

Abstract

This experiment was conducted to confirm the relationship between dietary lipid levels and n-3 highly unsaturated fatty acids (n-3HUFA) contents and to determine a suitable n-3HUFA content in diet for fingerlings of red sea bream by feeding them with various white fish meal-casein diets containing different amounts of lipid (5-20%) and n-3HUFA (1.2-4.2%) at a fixed protein level of 52%.At a level of 10% lipid, growth was lowered as n-3HUFA content in the diet increased, and the lowest feed performances were obtained in fish fed on a diet containing 3.7% n-3HUFA. On the other hand, at 15% lipid, the growth and feed efficiency were not affected by elevation of dietary n-3HUFA content, reaching a maximum at 3.7% n-3HUFA. Furthermore, at a level of 20% lipid, growth rate and feed efficiency were also improved as the n-3HUFA content increased, recording high in diets containing n-3HUFA above 3.7%. These results clearly indicated that the n-3HUFA content in diet should be increased in proportion to dietary lipid levels to obtain maximum growth. Moreover, the best growth and feed efficiency were obtained in fish fed on a diet with 15% lipid when n-3HUFA was adjusted to the level mentioned above.Thus, the growth of red sea bream fingerlings was found to be greatly influenced by dietary n-3HUFA levels, a suitable level being approximately 20% in dietary lipid regardless of lipid levels.

Criteria for Safe Use of Plant Ingredients in Diets for Aquacultured Fish

“…It has also been suggested that the EFA requirement in marine fish should be calculated in percent of lipid rather than in percent of diet. In red sea bream and yellowtail the EFA requirement has been estimated at 20% n-3 HUFA of dietary lipid (Takeuchi et al 1992a; while 10% seems sufficient in red drum (Sciaenops ocellatus) (Lochmann and Gatlin 1993). Regardless of species, 22:6n-3 appears to be the primary EFA followed by 20:5n-3.…”

Suitable Levels of n-3 Hihgly Unsaturated Fatty Acid in Diet for Fingerlings of Yellowtail.

“…On the other hand, the amount of essential fatty acids (EFA), such as linolenic acid and n-3HUFA, required to achieve maximum growth is known to increase along with increase in the dietary lipid level in rainbow trout and red sea bream. 2,3) This experiment was, therefore, conducted to confirm the relationship between dietary lipid levels and n-3HUFA contents, and to determine a suitable n-3HUFA content in the diet for fingerlings of yellowtail, by feeding them with various white fish meal diets containing different amounts of lipid (6-20%) and n-3HUFA (1.5-5.2%) at a fixed protein level of 50%. Four levels of lipid in diet were prepared, and at each lipid level, 1.5-5.2% of n-3HUFA were added at a fixed protein level of 50% which was suggested to be suitable in the previous experiment.1) These experimental diets were supplied to fish in dry pellet form.…”

Macronutrient Requirements of Silvery-Black Porgy (Sparidentex hasta): A Comparison with Other Farmed Sparid Species

“…No statistically significant differences were observed in growth (SGR and WG) and feed utilization parameters among different treatments, whereas, in other sparid species, the best growth performance in juvenile P. major [126] and juvenile S. aurata [127] was reported to occur at a DHA/EPA ratio of 0.5. However, in the study from Mozanzadeh et al [125], SGR and FCR values in S. hasta juveniles were not affected by different dietary DHA/EPA ratios, possibly reflecting species-specific differences with regard to P. major [113] and S. aurata [126]. These results in S. hasta suggested that either fatty acid (DHA or EPA) was able to meet the essential fatty acid requirements, if sufficient total n-3 LC-PUFAs were supplied in the diet.…”

“…In this context, most of the studies conducted in marine carnivorous fish species so far established an optimal dietary n-3 LC-PUFA requirement of 0.5%-2% of dietary DM [7]. Regarding sparids, the minimum requirement in dietary n-3 LC-PUFAs (DHA + EPA) required for optimal growth and development in juveniles has been reported to be about 1.0 in S. aurata [111], 1.3 in silver seabream, Rhabdosargus sarba [112] and 3.7 in P. major [113]. In S. hasta, the optimum dietary level of n-3 LC-PUFA in juveniles (BW i = 13.3 ± 0.1g) was determined in a nutritional study using five isonitrogenous (ca.…”