Please cite this article in press as: El-Moghazy M, et al. The possible effect of diets containing fish oil (omega- 3) on hematological, biochemical and histopathogical alterations of rabbit liver and kidney. Biomed Prev Nutr (2014), http://dx.doi.org/10.1016/j.bionut.2014.03.005 ARTICLE IN PRESS G Model BIONUT-224; No. of Pages 7 Biomedicine & Preventive Nutrition xxx (2014) xxx–xxx Available online at ScienceDirect www.sciencedirect.com Original article The possible effect of diets containing fish oil (omega-3) on hematological, biochemical and histopathogical alterations of rabbit liver and kidney Mostafa El-Moghazy a , Nahla S. Zedan b , Afaf M. El-Atrsh c , Mohamed El-Gogary d , Ehab Tousson c,e,∗ a Animal Production Department, Faculty of Agriculture, Doumyate University, Doumyate, Egypt b Home Economic, Specific Education, Kafer El-Shiek University, Kafer El-Shiek, Egypt c Department of Zoology, Faculty of Science, Tanta University, Tanta, Egypt d Poultry Production Department, Faculty of Agriculture, Mansoura University, Mansoura, Egypt e Department of Biology, Faculty of Science, Tabuk University, 71491 Tabuk, Saudi Arabia a r t i c l e i n f o Article history: Received 20 February 2014 Accepted 10 March 2014 Keywords: Natural materials Fish oil Omega-3 Feeding diet supplemented Rabbits a b s t r a c t The dietary intake of omega-3 polyunsaturated fatty acids has emerged over the past 20 years as an important way to modify cardiovascular risk. The present study aimed to evaluate the possible effects of a partial replacement of soybean meal in control economic diet by different concentrations of fish oil on the possible harmful changes in histological structure of liver and kidney and blood parameters in rabbits. A total of 36 adult New Zealand rabbits were equally divided into four groups, (control diet and control diet supplemented with different concentrations of fish oil at levels of 0.5, 1.0 and 1.5 mL fish oil per day/kg live body weight) and dissected after 6 weeks. Our results showed that, feeding diet supplemented with fish oil were significantly increased the percentages of hemoglobin, platelets, the mean corpuscular hemoglobin, WBCs count, total proteins, albumin, albumin/globulin ratio, S GOT and testosterone and significantly decreased the total lipids, cholesterol and triglycerides. The used of fish oil are good supplements for growing rabbits without any adverse effect on histological structure of liver and kidney in rabbits. © 2014 Elsevier Masson SAS. All rights reserved. 1. Introduction Because of increasing the cost of animal feed ingredients as well as the high demand, especially for the protein supplements, several efforts were carried out to use untraditional feed protein ingredi- ents to participate in facing feed shortage problem and at the same time to decrease feeding costs [1,2]. Lipids are important nutri- ents, providing 25–45% of dietary energy in most affluent societies, storage and transport of energy, for insulation and for mechani- cal protection [3]. In addition, lipids provide polyunsaturated fatty acids that are essential nutrients of importance for several cellu- lar functions in the body including ligands for transcription factors, precursors of signal molecules and building blocks in all cells of the body [4,5]. ∗ Corresponding author. Department of Zoology, Faculty of Science, Tanta Univer- sity, Tanta, Egypt. Tel.: +20 96 65 36 51 9175. E-mail address: toussonehab@yahoo.com (E. Tousson). Fat is a macronutrient that is considered to be a major source of calories or energy [6,7]. Although some fat in the diet is neces- sary, too much of fat can lead to heart diseases, cancers, obesity and other health problems [8]. They can be saturated, monoun- saturated or polyunsaturated. Saturated fatty acids contain no double bond, monounsaturated one double bond and polyunsat- urated contains two to six double bonds. The polyunsaturated fatty acids of four to six double bonds are a characteristic for fish oil, resulting in the unique health property often referred as the omega-3 fatty acids [5]. Long chain and intermediate chain fatty acids must be consumed as part of the diet because they can- not be synthesised by humans [9]. Investigations of fish oils have not only shown their importance as a dietary source of vitamins A and D, but also that they are very rich in fatty acids of long chained omega-3 [10]. It is not known which biological effects of omega-3 fatty acids are essential, but it is possible that the omega- 3 fatty acid-derived eicosanoids are crucial, as well as the unique structural properties of omega-3 fatty acids for cell membranes [11]. http://dx.doi.org/10.1016/j.bionut.2014.03.005 2210-5239/© 2014 Elsevier Masson SAS. All rights reserved.