不同植物油对大规格吉富罗非鱼生长性能、组织脂肪酸组成的影响

本试验旨在探究大规格吉富罗非鱼(GIFT)对不同植物油的利用效果,筛选出大规格吉富罗非鱼饲料中合适的植物脂肪源。分别以大豆油(SO)、棕榈油(PO)、棉籽油(CO)、菜籽油(RO)、磷脂油(SL)和大豆油∶棕榈油∶棉籽油∶菜籽油∶磷脂油=1∶1∶1∶1∶1的混合油(MIX)为脂肪源配制6种等氮等脂的试验饲料,饲喂初始体重为(229.92±0.31)g的吉富罗非鱼8周。每种试验饲料投喂4个网箱(重复),每个网箱放养50尾。结果表明:对于增重率和特定生长率,棉籽油组和混合油组显著低于菜籽油组(P0.05)。菜籽油组饲料系数显著低于混合油组(P0.05),其他各组间无显著差异(P0.05)。混合油组蛋白质效率显著低于菜籽油组和磷脂油组(P0.05)。混合油组肝体指数显著高于棕榈油组和菜籽油组(P0.05)。大豆油组、菜籽油组、棕榈油组和磷脂油组在增重率、特定生长率和饲料系数方面没有显著差异(P0.05)。大豆油组和菜籽油组肌肉饱和脂肪酸总量显著低于其他各组(P0.05)。对于肌肉中n-3系脂肪酸/n-6系脂肪酸,菜籽油组显著高于其他各组(P0.05),棉籽油显著低于其他各组(P0.05)。棉籽油组肝脏饱和脂肪酸总量显著高于其他各组(P0.05),菜籽油组则显著低于其他各组(P0.05);对于肝脏n-3/n-6,菜籽油组显著高于其他各组(P0.05)。各组肌肉脂肪酸组成与饲料脂肪酸组成的相关系数均高于肝脏脂肪酸组成与饲料脂肪酸组成的相关系数。在饲料脂肪酸组成与肌肉或肝脏脂肪酸组成的相关系数中,均以棕榈油组最大,磷脂油组最小。由此得出,大豆油、棕榈油、菜籽油和磷脂油可以作为大规格吉富罗非鱼(体重为230~790 g)饲料中良好的脂肪源。大规格吉富罗非鱼肌肉中脂肪酸组成一定程度上被饲料脂肪酸组成影响,但肝脏脂肪酸组成与饲料脂肪酸组成的相关性较小。

Effects of Different Vegetable Oils on Growth Performance and Tissue Fatty Acid Composition of Large Size Genetically Improved Farmed Tilapia (Oreochromis niloticus)

This experiment was conducted to explore the utilization effects of different vegetable oils for large size genetically improved farmed tilapia ( GIFT, Oreochromis niloticus) , and to screen out the optimal vegeta-ble lipid sources for large size GIFT. Six isonitrogenous and isolipidic experimental diets were prepared with the lipid sources were soybean oil ( SO) , palm oil ( PO) , cottonseed oil ( CO) , rapeseed oil ( RO) , phospholip-id ( SL) and mixture oil ( MIX, SO∶PO∶CO∶RO∶SL=1∶1∶1∶1∶1) , respectively, to fed GIFT with an initial body weight of (229.92±0.31) g for eight weeks. Each experimental diet was fed four net cages and each net cage cultured 50 fish. The results showed as follows: the weight gain rate and specific growth rate of CO and MIX groups were significantly lower than those of RO group (P<0.05). The feed conversion ratio of RO group was significantly lower than that of MIX group (P<0.05), but no significant difference among other groups was found (P>0.05). The protein efficiency ratio of MIX group was significantly lower than that of RO and SL groups ( P<0.05) . The hepatosomatic index of MIX group was significantly higher than that of PO and RO groups ( P<0.05) . There were no significant differences in the weight gain rate, specific growth rate and feed conversion ratio among SO, RO, PO and SL groups ( P>0.05) . The total amount of muscle saturated fatty acids of SO and RO groups was significantly lower than that of other groups ( P<0.05) . For muscle n-3 fatty acids/n-6 fatty acids, RO group was significantly higher than that of other groups (P<0.05), but CO group was significantly lower than that of other groups (P<0.05). The total amount of liver saturated fatty acids of CO group was significantly higher than that of other groups ( P<0.05) , but that of RO group was sig-nificantly lower than that of other groups ( P<0.05) . For muscle n-3 fatty acids/n-6 fatty acids, RO group was significantly higher than other groups ( P<0.05) . The related coefficients between muscle fatty acid composi-tion and dietary fatty acid composition were higher than the related coefficients between liver fatty acid compo-sition and dietary fatty acid composition. Among the related coefficients between muscle or liver fatty acid com-position and dietary fatty acid composition, the highest values were found in PO group and the lowest values were found in SL group. The results suggest that RO, SO, PO and SL can be good lipid sources for the diet of large size GIFT ( body weight:230 to 790 g) . Fatty acid composition of muscle in large size GIFT is affect by dietary fatty acid composition on a certain extent, but the correlation between liver fatty acid composition and dietary fatty acid composition is smaller.