Effects of dietary choline-chloride, betaine and lysophospholipids on the growth performance,fat metabolism and blood indices of crucian carp (<I>Carassais auratus gibelio</I>)

Abstract

A feeding experiment was carried out to evaluate the growth performance,fat metabolism and blood indices of diets containing different additives by crucian carp,Carassius auratus gibelio [mean initial weight of (7.46 ± 0.2)g],for 67 days. 450 healthy fish were randomly divided into five groups in the experiment,group 1 was control group fed basic feed,whereas groups 2,3,4 and 5 were fed the basic feed added with 0.05% lysophospholipids,0.1% lysophospholipids,0.1% betaine and 0.15% choline-chloride,respectively. At the end of the experiment,growth performance,fat metabolism and blood biochemical parameters were observed to estimate the function of these three additives. The results showed that weight growth ratio (WGR) of carps in groups 4(added with 0.1% betaine )and 5(added with 0.15%choline-chloride) tended to be higher than that of fish in group 1 (control) and this difference was significant (P0.05),and a lower feed conversion ratio (FCR) was found in groups 3 (added with 0.1% lysophospholipids),4 (added with 0.1% betaine) and 5(added with 0.15%choline-chloride) too (P0.05). The apparent digestibility coefficients (ADC) of nutrients and crude protein content in body composition were significantly higher in experimental groups than those in control group (P0.05). However,the liver fat,muscle fat content in experimental groups were lower than those in the control group,of which the test group of liver body ratio,liver fat content was significantly lower than that in the control group (P0.05). The triglyceride levels in groups 4 (added with 0.1% betaine) and 5(added with 0.15%choline-chloride) were lower than those in control group while the triglyceride levels in groups 2(added with 0.05% lysophospholipids) and 3(added with 0.1% lysophospholipids) were higher than those in control group (P0.05). Reduced plasma cholesterol levels were found in experimental groups while the increased free fatty acid contents were observed in experimental groups (P0.05). The experimental groups significantly increased superoxide dismutase (SOD) of the volume (P0.05),reduced malondialdehyde (MDA) and alkaline phosphatase (AKP) of the volume (P0.05),while aspartate aminotransferase (GOT),alanine aminotransferase (GPT),glucose (Glu) have no significant effect (P0.05). In conclusion,it could improve growth performance,reduce the fat content in liver and enhance antioxidation function obviously by adding 0.1% lysophospholipids,betaine and 0.21% choline-chloride in basic diet of crucian carp,Carassius auratus gibelio in our study.