Effects of different lipid sources in the silkworm pupa-based diet for mirror carp (Cyprinus carpio var. specularis) on growth performance, body composition and health status

A total of 324 healthy mirror carps Cyprinus carpio var. specularis initial weight:(10.700.70) g were randomly and equally distributed in 12 breeding cylinders with the indoor circulating water system. 2% soybean oil (SO), rapeseed oil (RO), ?sh oil (FO), and mixed oil (MIX, in which soybean oil, rapeseed oil and fish oil are 1:1:1) were added to the silkworm pupa based diet respectively, and four groups of isonitrogenous (36.5% crude protein), and isolipidic (7% crude fat) experimental diets were formulated. They were fed to apparent satiation three times a day for 58 days, and the effects of different lipid sources on growth performance, body composition and health status were discussed. The following results were concluded. Firstly, the final weight of SO group was significantly heavier than that of the MIX group (P0.05); SO group showed the highest intestine length ratio, both of condition factor and intestine index in SO group were significantly higher than those in FO group (P0.05). Hepatosomatic index of MIX group was obviously lower than those of FO and SO group, meanwhile hepatosomatic index of RO group was lower than that of SO group (P0.05). Secondly, whole body moisture of SO group was significantly higher than those of the RO group and the MIX group, the whole body crude fat of SO group was lower than those of other groups (P0.05); muscle moisture of SO group was significantly higher than those of the FO group and the MIX group (P0.05); however, little influence on whole body, muscle crude protein, ash and muscle crude fat, hepatopancreas chemical composition (P0.05). Thirdly, fatty acids composition in hepatopancreas and muscle generally reflected the composition in the diet; polyunsaturated fatty acid (PUFA) in hepatopancreas showed similar level between fish fed SO and RO diets, which were significantly higher than FO group (P0.05). Muscle PUFA level in SO group was higher than that in FO group, while muscle HUFA in RO group was higher than that in FO and MIX group (P0.05). Fourthly, the GLU contents of RO group was in a higher level than that of SO group (P0.05), and the four lipid sources do not affect the other serum biochemical indices signi?cantly (P0.05). Fifthly, there was no significant difference of serum T-SOD activity among the four groups (P0.05). GSH-XP activity of SO group was in the highest level, AKP activity of FO group in the lowest level, and MDA contents of SO group was lower than that of FO and MIX groups (P0.05). Hepatopancreas T-SOD activity of FO group was in the highest level, AKP activity of FO group was obviously better than those of RO and MIX group, and GSH-XP activity of FO group was better than that of MIX group (P0.05). There was no signi?cant difference of MDA contents among the four groups (P0.05). In conclusion, in silkworm pupa based diet, mirror carps have the best performance by using soybean oil as the oil resource, following which was the rapeseed oil, while fish oil and mixed oil had the poorest effects in silkworm pupa based diet.