FARKLI BİTKİSEL YAĞLAR İLAVE EDİLEN DİYETLERİN LEVREK (Dicentrarchus labrax L., 1758) YAVRULARINDA BÜYÜME PERFORMANSI VE VÜCUT KOMPOZİSYONUNA ETKİLERİ

Ozet Bu arastirmada, yemlerinde balik yagi yerine kullanilan bitkisel yaglardan soya. misir, aycicek ve zeytin yaginin deniz levregi ( Dicentrarchus tabrax ) yavrularinin buyume performansi ve vucut kompozisyonuna etkisi incelenmistir. Arastirmada, kontrol grubuna balik yagi, deney grubu l'e soya yagi. deney grubu II'ye aycicek yagi, deney grubu lll'e misir yagi ve deney grubu IV'e ise zeytin yagi kullanilan deney yemleri verilmistir. Butun deney yemlerinde esil olarak ortalama %12.33 oraninda yag kullanilmistir Baslangic agirliklari ortalama 7,58 g olan baliklar 75 gun sureyle Milas-Orende bulunan ozel bir isletmede beslenmislerdir. Deney sonunda, baliklarin ortalama bireysel canli agirlik artislari kontrol grubunda 31.27 g. deney grubu I'de 26.04 g, deney grubu H'de 24.79 g. deney grubu III'te 24.34g ve deney grubu IV'te 25.76 g, yemden yararlanma oranlan da sirasiyla 1.59, 1.78, 1.86, 1.94 ve 1.81 olarak saptanmistir. Yapilan kimyasal analizlerde karkastaki toplam ham yag orani baslangicta %4.88 iken deney sonunda kontrol ve deney gruplarinda sirasiyla %4.55, %5.03, %4.99, %6.38 ve %6.38, karacigerdeki toplam ham vag orani baslangicta %13.84. deney sonunda sirasiyla % 19.89. %23.33. %26.97, %3t.4I ve %33.07 olarak bulunmustur Butun gruplardaki canli agirlik artisi, yemden yararlanma orani, karkastaki ve karacigerdeki toplam ham yag miktarlari icin yapilan varyans analizi sonucunda gruplar arasindaki farkin onemli (P<0.05) oldugu gorulmustur. Hepatosomatik indeks degeri baslangicla %2.06 iken deney sonunda balik yagi ile beslenen baliklarda %2.10, bitkisel yaglar ile beslenen gruplarda ise yakin degerlerde ve sirasiyla %2.42. %2.45. %2.3I ve %2.43. benzer bir sekilde viserosomatik indeks baslangicta %8.45 ve deney sonunda gruplarda sirasiyla %9.24. %10.19, %11.51, %11.70 ve %11.94 olarak saptanmistir. Hepatosomatik indeks ve viserosomatik indeks degerleri bitkisel yaglar ile beslenen baliklarda benzer ancak balik yagi grubuna (Kontrol grubu) gore daha yuksek (P<0.05) bulunmustur. Anahtar Kelimeler: Deniz levregi ( Dicentrarchus tabrax ). beslenme, balik yagi, bitkisel yaglar, buyume performansi, vucut kompozisyonu. THE EFFECTS OF DIETARY SUPPLEMENTATION WITH DIFFERENT VEGETABLE OILS ON GROWTH PERFORMANCE AND BODY COMPOSITION IN SEABASS {DICENTRARCHUS LABRAX L. , 1758) JUVENILES Abstract The effect of feeds included some vegetable oil such as soybean, corn, sunflower and olive oil substitute of fish oil on the growth performance and body composition of sea bass ( Dicentrarchus labr ax) juvenile were investigated in this study. Fish oil is used as an oil source in the control group and soybean oil. sunflower oil. corn oil. and olive oil in the experimental groups respectively. Mean 12.33% oil was used in diets for all groups. At the beginning of feeding trials mean live weight of fish was found 7.58 g and this study was performed tor 75 days in a private hatchery in the town Oren, Mugla (Turkey). Growth performance of the fish was calculated by measuring live weight gain, specific growth rate, condition factor, hepatosomatic and viserosomatic index values. In addition, the amount of the nutrients in the fish and feed samples and total fat in the fish liver were determined. At the end of the study mean live weight gain offish were found 31.27 g in control group and 26.04 g. 24.79 g. 24.34 g. 25.76 g in the experimental groups I, II, II, IV respectively. Feed conversion ratio was found 1.59 in the control group and 1.75, 1.86, 1.94, 1.81 in the experimental group's respectively. The difference among the groups were found significant as a result of variance analyses for growth performance and body composition (P<0.05). According to the results chemical analysis of total fat in the fish carcass were found 4.48% at the beginning and 4.55% in control group, 5.03%, 4.99%, 6.38%, 6.38%. in the experimental groups respectively at the end of feeding trials. Liver fat contents were found 13.84% at the beginning and 19.89%, 23.33%, 26.97%, 31.41% and 33.07% in the control and experimental groups I, II. II. IV respectively at the end of trial. Hepatosomatic index (HSI) values were found 2.06% at the initial and 2.10% in fish oil group, 2.42%, 2.45%, 2.31%, 2.43% in the other experimental groups at the end of trial. In similarly, viscerosomatic index (VSI) values were found 8.45% at the beginning and 9.24%, 10.19%, 11.51%, 11.70%, 11.94% in the control and the other experimental groups at the end of trial respectively. HSI and VSI values were found similar in the experimental groups fed the feeds included different vegetable oils and higher than the control group fed fish oil added feeds