The Effects Of Fat And Carnitine Levels On Growth Performance And Physiological Function Of Juvenile Gift, Oreochromis Niloticus

The present experiment investigated the effects of fat and carnitine levels on growth performance and physiological function of juvenile GIFT, preliminary got the relationships between fat or carnitine levels and GIFT liver disease, which can provide certain theoretical basis for the prevention of GIFT liver disease. Experiment using 3 x 3 two-factor experimental design, the design level of fat was 2%,6%,10%, each fat levels correspond of carnitine levels of 100 mg/kg,500 mg/kg and 1000 mg/kg, test a total of nine groups, each group set up three repeat, each group of 50 tail fish, feeding the juvenile GIFT which average initial body weight was (2.9+0.3) g for 70 days. Following results were obtained:1. the impact on growth performance:mainly carnitine levels of tilapia larvae had great effects on the growth index (P<0.05).When the low level of carnitine, fat levels change will affect the growth of juvenile tilapia. From the measured data of a week on juvenile tilapia, fat and carnitine levels of juvenile tilapia had great impact on weight gain rate, specific growth rate and feed coefficient (P<0.01).2. The impact on nutrition, mainly fat levels had great effects on gift tilapia larvae nutrition (P< 0.01).Especially the fat level was 10% and the effect was significantl (P< 0.01), higher than the fat levels were 2% or 6%.3. The HSI and amount of fat in muscle of Tilapiat:Fat level had significant influence on the HSI of tilapia larvae (P< 0.05), had highly significant influence on amount of fat in muscle of Tilapiat (P< 0.01). When carnitine level was constant,, amount of fat in muscle of Tilapiat was increased with the increase of fat levels in the feed.4.Effect on the digestive enzymes:fat and carnitine levels had significant effects on the digestive enzymes activity (P< 0.01).When fat levels of the feed in a certain level, carnitine levels of feed rise will affect the activity of digestive enzymes.In general, when the feed fat was 6%, carnitine level was 500 mg/kg, digestive enzymes activity of tilapia larvae was the largest5. the impact on fat metabolism enzymes:Mainly, fat levels and carnitine significantly influence the fat metabolism enzyme activity (P< 0.01).When fat levels of feed in is certain, carnitine levels of feed rise will affect all the fat metabolism enzyme vigor, in general, it was negatively correlated with both.6. the influence on the serum biochemical indicators:Mainly, carnitine levels of tilapia larvae had siginificant influence on serum biochemical (P< 0.01). when carnitine levels of feed is certain, fat levels of 6% and 10%, AST, CHOL, HDL and LDL-C significantly above the level of the 2%(P< 0.01), and look from the serum biochemical indicators, fat levels of feed were 6% and 10% on tilapia larvae had been varying degrees of liver damage.7.The influence on immune:under the case of carnitine levels, carnitine levels had significant influence on the WBC of tilapia larvae (P< 0.01), had influence on ALB and C3 (P< 0.05).Under the fat levels of tilapia larvae had significant influence on C3 (P< 0.01). When the fat levels of feed were 8% and 10%, it can reduce the immunity of tilapia larvae; when fat levels of feed was 6%, it had normal immune function.8.The effects on the liver histology:when the fat level was 2%, tilapia liver histological impact is normal.when fat level was 6% or 10%,it can lead to varying degrees of liver damage, and liver lesions happened.