Browsing by Author "Engin, Kenan"

Now showing 1 - 2 of 2

Effects of Dietary Nucleotide Yeast on Immune Responses and Antioxidant Enzyme Activities of Rainbow Trout Juveniles (Oncorhynchus Mykiss)
(Israeli Journal of Aquaculture-bamidgeh, 2016) Ozluer-Hunt, Arzu; Ozkan-Yilmaz, Ferbal; Berkoz, Mehmet; Engin, Kenan; Gunduz, Suna Gul; Yalin, Serap
This study aimed at demonstrating the effects of dietary supplementation of nucleotide yeast base protein (Nu-Pro (R)) (NP) on the antioxidant enzyme activities and immune response in liver and blood tissues of rainbow trout (Oncorhynchus mykiss). Fish with an average initial weight of 27.75 +/- 0.26 g were randomly assigned to four groups with three replicates. Throughout the 60 day grow-out period the control group was fed a fish meal based basal diet, and three other groups were fed diets in which 20 (NP 20), 40 (NP 40) and 60 % (NP 60) fish meal was substituted with nucleotide (Nu-Pro (NP) yeast). There were no significant changes of superoxide dismutase (SOD) and catalase (CAT) activities in liver among the experimental groups. A significant decrease (P<0.05) in malondialdehyde (MDA) level of tissue was observed in all nucleotide supplemented groups when compared to the control group. Serum lysozyme (LYZ) and myeloperoxidase (MPO) activities and nitric oxide (NO) level of liver tissue were significantly (P<0.05) increased in fish fed with nucleotide yeast based protein diets. The results showed that the fish in all nucleotide supplemented groups showed significantly better antioxidant activity and immune responses.
The Effects of Fish Meal Replacement by Yeast Based Nucleotides on Growth, Body Composition and Digestive Enzyme Activity in Rainbow Trout Juveniles (Onchorchyncus Mykiss)
(Israeli Journal of Aquaculture-bamidgeh, 2014) Hunt, Arzu Ozluer; Yilmaz, Ferbal Ozkan; Engin, Kenan; Berkoz, Mehmet; Gunduz, Suna Gul; Yalin, Serap; Sahin, Nefise Ozlen
This 60 day study investigated the effects of organically certified nucleotide yeast-derived protein source (Nu-Pro (R)) on growth, feed efficiency, fillet proximate composition and digestive enzymes in rainbow trout (Onchorhyncus mykiss). Diets were isonitrogenous and isocaloric. Three experimental diets wherein 20%, 40% and 60% of the fish meal content was replaced by Nu-Pro (R), were compared to the control diet in which the crude protein content was anchovy fish meal and corn gluten meal. The rainbow trout (initial weight 27 g/fish) were fed twice daily in 200-l Aqaria. Live weight gain increase ranged from 125-195% in fish fed the experimental diets. Results indicated that up to 40% fish meal protein can be replaced by Nu-Pro (R) without compromising growth rates, feed efficiency or the fillet biochemical composition in the rainbow trout. The effect of the dietary Nu-Pro (R) supplementation on digestion was partly observed by assaying the activity of pepsin, intestinal amylase, trypsin and lipase. Apart from amylase activity, results indicated that dietary supplementation of nucleotides is beneficial and may also have differential effects upon digestive enzyme activities.