ABSTRACT
The aim of this study was to investigate the effects of different dietary lipid sources on blood metabolites and testis development of male kids. Twenty-four goat kids (BW = 19.43±1.2 kg) were assigned to three equal groups and received one of three dietary treatments as follows: control (CO), soybean oil (SO) or fish oil (FO). All three diets were isonitrogenous and isoenergetic, but contained different fat sources. Prilled palm-oil (high in C16:0), soybean oil (high in C18:2 n-6) and fish oil (high in EPA 20:5 n-3 and DHA 22:6 n-3) were supplemented at 2% DM to control, soybean oil and fish oil diets, respectively. Testicular circumference, width, length and volume were obtained on kids at the beginning and end of experiment while testicular growth measures were defined as differences between these two measurements. At the end of experiment, blood samples were collected and kids were slaughtered. Immediately after killing testes were dissected, weighed, and fixed in 10% formalin for histological studies. Plasma glucose, triglycerides, total cholesterol, HDL and LDL cholesterol, and testosterone concentrations did not significantly differ among diets. FO diet significantly elevated (p<0.05) the testicular growth measurements (circumference, volume, width and length) and absolute fresh testis masses at slaughter compared to CO or SO diets. Also, FO diet showed a significant increase in the seminiferous tubule and lumen diameter, leydig cell, sertoli cell, spermatogonia cell, spermatocyte and spermatid cell counts (p<0.01) compared to other diets. Results show that fish oil supplementation to male growing kids improved testes development.