Eldsokey Nassef, Elsayed Hegazi, Ahmed Sherif, Mohamed Elshamy, Abdelnasser Bakr, Tarek Abouzed


The present study investigated the influence of altering omega 6 to omega 3 fatty acids (FA) ratio on growth, hemato- biochemical parameters and absorptive capacity of Nile tilapia. One hundred and fifty fingerlings (25.1±0.3 g), were assigned into 3 groups (5 replicates each) and fed on iso-caloric and iso-nitrogenous diets. Diets were supplemented with fish and soy oil to create 3 different ratio of omega 6 to omega 3 FA, namely, 0.91, 2.85 and 9.3 parts of omega 6 to 1 part of omega 3 (R1, R3 and R9, respectively). Increasing the ratio from R1 to R9 significantly decreased average daily gain and increased feed conversion ratio. Also this alteration decreased ash content in the carcass on the expense of ether extract. Number of erythrocytes, packed cell volume, hemoglobin concentration were significantly increased in fish fed R1. Feeding R9 increased heterophils and decreased lymphocytes as compared with R1 and R3. Fish fed R1 significantly had high serum protein and serum antibacterial activity (47.6%) than R9 (43.5%) and R3 (44.9%). Feeding R1 significantly decreased serum triglycerides, cholesterol and creatinine. Feeding R3 and R1 enhanced absorptive capacity of jejunum villi more than the group fed R9. Increasing the ratio of omega 6 to omega 3 FA from R1 to R9 decreased growth performance through decreasing absorptive capacity of jejunum villi. However, Feeding R3 had a positive effect on growth performance and absorptive capacity of the intestine of Nile tilapia.

Key words: fish oil; growth performance; intestinal villi; Nile tilapia; soybean oil

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Food and Agriculture Organization. Fish to 2030 Prospects for Fisheries and Aquaculture. World bank report number 83177-GLB. De-cember 2013.

National Research Council. Nutrient re-quirements of fish and shrimp. National Acad-emies Press, Washington 2011.

El-Adawy M, El-Aziz MA, El-Shazly K, Ali NG, El-Magd MA. Dietary propionic acid enhances antibacterial and immunomodulatory effects of oxytetracycline on Nile tilapia, Oreo-chromis niloticus. Environmental Science and Pollution Research, DOI: 101007/s11356-018-3206-5 2018.

Turchini G, Torstensen B, Ng W. Fish oil replacement in finfish nutrition. Reviews in Aquaculture 2009; 1:10–57.

Montero D, Socorro J, Tort L, Caballero M, Robaina L, Vergara J, Izquierdo M. Glomer-ulonephritis and immunosuppression associated with dietary essential fatty acid deficiency in gilthead sea bream, Sparus aurata L., juveniles. Journal of Fish Diseases 2004; 27: 297–6.

Association of Official Analytical Chem-ists. Official Method of Analysis 2010; 18th ed. AOAC, Gaithersburg, MD.

Lucky Z. Methods for Diagnosis of Fish Disease 1977. Amerind Publishing Co. New York, 1977.

Schalm O. Veterinary hematology 1986. Lea and Febiger Philadeiphia. 4th ed.

Barros M, Lim C, Klesius P. Effect of soybean meal replacement by cottonseed meal and iron supplementation on growth, immune response and resistance of channel catfish (Ic-talurus puctatus) to Edwarsiella ictaluri chal-lenge. Aquaculture 2002; 207: 263–79.

Weichselbaum C. An accurate and rapid method for the determination of proteins in small amounts of blood serum and plasma. American journal of clinical pathology 1946; 16: 40–9.

Doumas B, Waston W, Biggs H. Albumin standards and the measurements of serum al-bumin with Bro-mocresol Green. Clinica Chim-ica Acta 1971; 31: 87–6.

Abdelhady D, El-Abasy M, Abou-Asa S, Elbialy Z, Shukry M, Hussein A, Saleh A, El-Magd M. The ameliorative effect of Aspergillus awamori on aflatoxin b1-induced hepatic dam-age in rabbits. World Mycotoxin Journal 2017;10:363–73.

Kajita Y, Sakai M, Atsuta S, Koba-yash M. The immunostimulatory effects of levami-sole on rainbow trout, On-corhnchus mykiss. Fish Pathology1990; 25: 93–8.

SPSS. Statistical and package for social science, SPSS for windows release14.0.0, 19 June, 2004." Standard version, copyright SPSS Inc., 1989- 2004.

Szabo A, Mezes M, Hancz C, Molnar T, Varga D, Romvari R, Febel H. Incorporation dynamics of dietary vegetable oil fatty acids into the triacylglycerols and phospholipids of tilapia (Oreochromis niloticus) tissues (fillet, liver, visceral fat and gonads). Aquaculture Nu-trition 2011; 17: 132–47.

Peng X, Li F, Lin S, Chen Y. Effects of total replacement of fish oil on growth perfor-mance, lipid metabolism and antioxidant ca-pacity in tilapia (Oreochromis niloticus). Aqua-culture International 2016; 24:145–56.

Han C, Zheng Q, Feng L. Effects of total replacement of dietary fish oil on growth per-formance and fatty acid compositions of hybrid tilapia (Orechromis niloticus 9 O.aureus). Aqua-culture International 2013; 21:1209–17.

Ng W, Chong C, Wang Y, Romano N. Effects of dietary fish and vegetable oils on the growth, tissue fatty acid composition, oxidative stability and vitamin E content of red hybrid tilapia and efficacy of using fish oil finishing diets. Aquaculture 2013; 372–375: 97–110.

Ribeiro P, Logato P, Paula D, Costa A, Murgas L, Freitas R Effect of different oils in the diet on lipogenesis and the lipid profile of Nile tilapias. Rev Bras Zootec 2008; 37 (8):1331–7.

Rinchard J, Czesny S, Dabrowski K In-fluence of lipid class and fatty acid deficiency on survival, growth, and fatty acid composition in rainbow trout juveniles. Aquaculture 2007; 264:363–71.

Guler M, Yildiz M. Effects of dietary fish oil replacement by cottonseed oil on growth performance and fatty acid composition of rainbow trout (Oncorhynchus mykiss). Turk J Vet Animal Science 2011; 35 (3):157–67.

Villeneuve L, Gisbert E, Le Delliou H, Cahu C, ZamboninoInfante J. Intake of high levels of levels of vitamin A and polyunsaturat-ed fatty acids during different developmental periods modifies the expression of morphogen-esis genes in European sea bass (Dicentrachus labax). Br J Nutrition 2006; 95: 677–87.

Watkins B, Li Y, Lippman H, Seifert M. Omega-3 polyunsaturated fatty acids and skele-tal health. Exp Biol Med 2001; 226:485–97.

Caballero M, Izquierdo M, Kjorsvik E, Fernandez A, Rosenlund G Histological altera-tions in the liver of sea bream, Sparus aurata L., caused by

short or long term feeding with vegetable oils: recovery of normal morphology after feeding fish oil as the sole lipid source. J Fish Diseases 2004; 27:531–41.

Klinger R, Blazer V, Echevarria C Ef-fects of dietary lipid on the hematology of channel catfish, Ictalurus punctatus. Aquacul-ture 1996; 147, 225–33.

Bell J, McGhee F, Campbell P, Sargent J. Rapeseed oil as an alternative to marine fish oil in diets of post-molt Atlantic salmon (Salmo salar): changes in flesh fatty acid composition and effectiveness of subsequent fish oil “wash out.” Aquaculture 2003; 218:515–28.

Calder P. Polyunsaturated fatty acids and inflammation. Prostaglandins Leukotrienes Es-sential Fatty Acids 2006; 75: 197–202.

Genc E, Yilmaz E, Akyurt I. Effects of dietary fish oil, soy-acid oil, and yellow grease on growth and hepatic lipidosis of hybrid tilapia fry. Israeli J Aquaculture-Bamidgeh 2005; 55: 90–6.

Robaina L, Izquierdo M, Moyano F, So-corro J, Vergara J, Montero D. Increase of the dietary n3/n6 fatty acids ratio and addition of phosphorus improves liver histology alterations induced by feeding diets containing soybean meal in gilthead seabream (Sparus aurata). Aq-uaculture 1998; 161: 281–93.

Menoyo D, Izquierdo M, Robaina, L, Gines R, Lopez-Bote C, Bautista J Adaptation of lipid metabolism, tissue composition and flesh quality in gilthead sea bream (Sparus au-rata) to the replacement of dietary fish oil by linseed and soybean oils. Br J Nutrition 2004; 92:41–52.

Leaver M, Villeneuve L, Obach A, Jen-sen L, Bron J, Tocher D, Taggart J. Functional genomics reveals increased cholesterol and highly unsaturated fatty acid biosynthesis after dietary substitution of fish oil with vegetable oils in Atlantic salmon (Salmo salar). BMC Ge-nomics 2008; 9:299. Doi: 10.1186/1471-2164-9-299.

Kiron V. Fish immune system and its nu-tritional modulation for preventive health care. Animal Feed Science Technology 2012; 173:111–33.

Mourente G, Good J, Bell J. Partial sub-stitution of fish oil with rapeseed, linseed and olive oils in diets for European sea bass (Dicen-trarchus labrax L.): effects on flesh fatty acid composition, plasma prostaglandins E-2 and F-2 alpha, immune function and effectiveness of a fish oil finishing diet. Aquaculture Nutrition 2005, 11:25–40.



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