2011 YÜksek lisans tez özetleri

Effect Of Dıets Contaınıng Vegetable Oıls On Growth And Fatty Acıd Composıtıon Of Raınbow Trout

In this study, the effect of feeds included different combinations of linseed, sesame and sunflower oils substitute of fish oil on growth performance, body composition and tissue fatty acid composition of juvenile rainbow trout (O. mykiss W., 1792) were investigated. Fish which were initial average weight 7,42 g were used for feeding trials during the 75 days.

Growth performance of fish were calculated as individual growth performance, specific growth rate, feed conversion ratio, condition factor, body composition, hepatosomatic and viscerosomatic index values. Proximate composition and fatty acid composition of experimental feeds or fish and total lipid in the liver samples of fish were determined. Evaluation of the economic analysis was also used in the diets.

At the end of feeding trials, mean individual weight gain of the fish was found the highest value (39,01 g) in control group (P<0,05). No significant differences were found among the other experimental diets which were used vegetable oils. Specific growth rate, feed conversion ratio and condition factor were not influenced by dietary treatments. However, viscerosomatic (15,57) and hepatosomatic (1,62) index values were significantly higher (P<0,05) in fish fed with BY30/SY35/AY35 diet.

Whole body lipid rates and fatty acid composition of fish were significantly affected by vegetable oils used in diets but the amount of total fat in test groups of fish liver were not affected by different oils. According to the results of the analysis, total body fat levels of fish fed diets containing sunflower oil was higher than the other experimental groups (P<0,05). Depending on the use of vegetable oil in diets increased the rates of n-6 PUFA. However, n-3 PUFA and n-3 HUFA ratio decreased (P<0,05). In our study, tissue fatty acid profiles of fish were directly affected by oils used in diets.

The economic analysis of diet formulations in this study indicated that the cost of the diet control group which used 100 % fish oil was the highest level (P<0,05). However, no significant differences were found among the other experimental diets containing vegetable oils. In addition, there was no significant difference among the all dietary treatments diets for EPI levels (P>0,05).

According to the all results, when fish growth performance and fatty acid composition were observed no negative effects were found when linseed, sesame and sunflower oil blends used in a part (substitute of fish oil by 70 %) or fully in the juvenile rainbow trout diets substitute of fish oil.