Omega-3 long-chain polyunsaturated fatty acids (LC-PUFAs), mainly eicosapentaenoic acid (20:5n-3; EPA) and docosahexaenoic acid (22:6n-3; DHA), have drawn increasing attention, recently due to their important disease-preventing and health-promoting functions. The present study investigates the fatty acids profile of rainbow trout cultured in different farms in the different provinces (Erzurum and Sakarya) of Turkey. After detecting lipids and fatty acids content, the amount of fillet required for weekly intake of 3.5 g EPA+DHA suggested by International Society for the Study of Fatty Acids and Lipids (ISSFAL) for human consumption was calculated for each farm. The amount of EPA+DHA in fillets from Erzurum and Sakarya were 236.2±91.8 and 193.8±75.1 mg/g lipid, respectively, with no significant difference between the two provinces. The amounts of fillet required for weekly intake of 3.5 g EPA+DHA suggested by ISSFAL were calculated as 714±215 and 896±590 g for the farms in Erzurum and Sakarya, respectively, with no significant difference between the two provinces. Based on our results, required EPA+DHA for healthy purposes could be achieved by consuming rainbow trout approximately two or three times a week depending on the farm and the portion size.

The present study was conducted to evaluate the effect of different dietary protein levels on digestive enzyme activities, nutrient assimilation as well as growth performance in striped catfish (Pangasianodon hypophthalmus). Fish were fed with four semi-purified formulated diets with increasing levels of protein: 30% (CP30), 35% (CP35), 40% (CP40) and 45% (CP45) for 12 weeks. At the end of the feed trial, the highest weight gain (29.88 g fish-1), specific growth rate (3.58%) and lower feed conversion ratio (1.91) were observed in fish that were fed with a 40% protein diet while CP30 treatment group had the poorest growth performance indicators (P<0.05). Proximate analysis revealed that fish fed with either CP40 (18.50%) or CP45 (19.33%) diets had the highest protein content in comparison to that fed CP30 (17.13%) and CP35 (17.00%) diets. Similarly, the highest body lipid content was CP35 (4.20%) treatment group and the lowest in CP40 (3.83%). The amino acid in the harvested fillets was also significantly higher (P<0.05) in both CP40 and CP45 dietary treatments. The increasing dietary protein level also elevated both protease and amylase activity, while lipase activity significantly decreased (P<0.05). The study revealed that a 40 % protein level diet produced from regional ingredients in the Middle East had yielded optimal growth performance and higher muscle quality in striped catfish.