Effect of different lipid sources in diet on growth performance and muscle fatty acid composition of three feeding habits fishes.

The experiment was to explore the effect of different fat sources in diet on growth of Ctenopharyngodon idella, Mylopharyngodon piceus and Carassius auratus gibelio, as well as conventional muscle nutrients and fatty acid composition. A total of 240 fish with an initial body weight of (34.8±0.4) g Ctenopharyngodon idella, (35.0±0.4) g Mylopharyngodon piceus, (26.3±0.1) g Carassius auratus gibelio were randomly divided into four groups with three replicates in each group and 60 fish in each replicate (three species mixed culture, 20 fish per species). The basic diet (BD group) without oil and fat was used as control group, and 6% soybean oil (SO group), fish oil (FO group) and lard (LO group) were added to basic diet as test groups. The experiment lasted for 8 w. The results showed that the average survival rate of the three species of fish in each group was significantly higher than that in BD group (P<0.05), and the survival rate of Mylopharyngodon piceus in test group was significantly higher than that in BD group (P<0.05). The total final weight and average weight gain of the three fish in each group were significantly higher than that in BD group (P<0.05). The feed coefficient of each group was significantly lower than that in BD group (P<0.05). The visceral body ratio and liver body ratio of Ctenopharyngodon idella in FO group were significantly higher than those in BD group (P<0.05), and the visceral body ratio and liver body ratio of Mylopharyngodon piceus in LO group were significantly higher than those in BD group (P<0.05). The visceral body ratio of Carassius auratus gibelio in BD group was significantly lower than that in other groups (P<0.05), and the liver to body ratio of Carassius auratus gibelio in FO group was significantly lower than that in other groups (P<0.05). The crude protein content of Ctenopharyngodon idella in FO group was significantly higher than that in BD group and SO group (P<0.05), and the crude protein content of Mylopharyngodon piceus in SO group was significantly lower than that in other groups (P<0.05). The crude fat content of Ctenopharyngodon idella in LO group was significantly higher than that in other groups (P<0.05), and the crude fat content of Mylopharyngodon piceus in SO group was significantly higher than that in other groups (P<0.05). The content of C16:0 was the highest in the three fish muscle fatty acids, followed by C18:1n-9, C18:0 and C18:2n-6. The content of C18: 2n-6, C18:3n-3 in SO group were significantly higher than other groups (P<0.05). The content of C20: 5n-3, C22:6n-3 in FO group were significantly higher than other groups (P<0.05). The content of C16:0, C18:1n-9 in LO group were significantly higher than those in other groups (P<0.05). The study indicates that adding fish oil to Ctenopharyngodon idella bait has a good growth-promoting effect, but adding 6% soybean oil and lard has no obvious growth-promoting effect, which indicates that Ctenopharyngodon idella has lower requirements for feed fat level. Adding 6% soybean oil, fish oil and lard to Mylopharyngodon piceus bait has better growth-promoting effect. Adding 6% fish oil and lard to Carassius auratus gibelio has better growth-promoting effect, but soybean oil has poor effect. [ABSTRACT FROM AUTHOR]