Studies On Riboflavin, Pyridoxine And Niacin Requirements Of Carassius Auratus Gibelio (Bloch)

Three growth trials were conducted to evaluate dietary riboflavin, pyridoxine and niacin requirements, and their effects on growth, feed utilization, physiological and biochemical index for gibel carp (Carassius auratus gibelio). In the first trial, 6 diets were formulated to contain different levels of riboflavin (1.51, 2.23, 4.97, 7.79, 11.82 and 16.85mg/kg diet). In the second trial, 7 diets were formulated to contain different levels of pyridoxine hydrochloride (0, 1.11, 3.29, 5.41, 12.70, 13.30 and 27.30 mg/kg diet). In the third trial, 7 diets were formulated to contain different levels of niacin (3, 10, 17, 30, 44, 64 and 91 mg/kg). In these experiments, specific growth rate (SGR), feed conversion efficiency (FCE), protein efficiency ratio (PER), hepatosomatic index (HIS), condition factor (CF), hematological biochemistry, body composition, liver vitamin concentration as well as related enzyme activities in fish livers were determined.The results are shown as follows:1. The dietary riboflavin, pyridoxine and niacin requirements for optimum SGR or enzymes activities of gibel carp was 3.76, 7.62-11.36 and 31.27 mg/kg diet, respectively.2. Fish fed the diet containing 4.97mg riboflavin/kg diet showed significantly higher specific growth rate, feed efficiency, protein efficiency ratio and condition factor than the fish fed the diet containing 1.51mg riboflavin/kg diet. Dietary riboflavin concentration has no significant effect on the FI, PRE and HSI.3. D-AAO activities increased with increased dietary riboflavin, but no significant differences were observed.4. With increasing dietary riboflavin, dry matter, crude protein and crude lipid contents of the final fish body increased, but no significant effect was found. Body ash content of fish fed 2.23 mg riboflavin/kg diet was significantly higher than the fish fed 4.97 mg riboflavin/kg diet.5. Fish fed the pyridoxine-free diet gained significantly lower body weight and showed significantly higher mortality than the fish fed the pyridoxine-supplemented diets. FCE, PER and HSI also increased with increased dietary pyridoxine.6. Gibel carp juveniles are highly susceptible to dietary pyridoxine deficiency and obvious deficiency symptom appeared. Fish fed the control diet became anorexic and lethargic and some even tetany and spasm form the second week of the feeding experiment.7. There was no significant difference between the diets with different pyridoxine levles, but there was an increase in RBC and Ht with increased dietary pyridoxine (up to 3.29mg/kg diet). GOT activity was significantly higher in the fish fed the diets of higher than 12.7mg pyridoxine/kg diet than those fed the control diet. GPT activity was significantly higher in the fish fed more than 5.41mg/kg diet than those fed other diets.8. Dry matter, crude protein and crude lipid contents were the lowest while ash content was the highest in the fish fed the control diet (pyridoxine free). The pyridoxine contents in liver reflected the supplementation level in the diet, and the values ranged from 1.80 to 4.33ug/g tissue.9. The fish fed diets containing 3, 10 and 17mg niacin/kg diet showed significant lower SGR than the fish fed the diets containing 30 and 44mg/kg diet. FCE and PER of the fish fed 30 and 44mg/kg diet was significantly higher than the fish fed the control diet.10. HSI of the fish fed 3mg/kg diet was significantly lower than the fish fed the diets containing higher than 30mg/kg diet. Fish fed diets containing 30 and 44mg/kg diet showed significantly higher CF than the fish fed diets of 3 or 10mg/kg diet.11. The fish fed the diets with 44mg nicin/kg diet showed significant higher FI than the control. The survival of the fish fed the diets containing 3-44mg niacin/kg showed significantly higher than those containing 64 or 91mg niacin/kg diet.12. Fish fed the control diet (3 mg niacin/kg diet) and 10mg niacin/kg diet became anorexic from the sixth week of the experiment. Some fish in these two groups showed fin lesion, dark skin coloration, dermatitis from the 12th week of the experiment. 13. The values of RBC were higher in the fish fed diets containing 44mg niacin/kg diet. The highest value of Ht was observed in the fish fed the diet supplemented with 17mg /kg diet, followed those fed the diets with 30 or 44mg niacin/kg diet. These three groups showed significant higher Ht than the control.14. Lipid content was significantly higher in the fish fed the diets supplemented with niacin at higher than 30mg/kg diet than that in the fish fed the control diet. There was no significant difference in the protein content between different diets. The energy content was highest in the fish fed the diet containing 44mg niacin/kg diet, and followed by 30 and 64mg/kg diet, and these groups were all significantly higher than the control. Dry matter in the fish fed the control diet is lower than those in the fish fed 30 or 44mg niacin/kg diet. The fish fed the diet containing 10mg niacin/kg diet has the highest body ash content.15. The niacin contents in liver reflected the supplementation level in the diet, and ranged from 37 to 75ug/g tissue.In conclusion, the optimum dietary riboflavin, pyridoxine and niacin contents in could improve growth performance, physical metabolism and healthy in gibel carp.