| Japanese flounder (Paralichthys olivaceus) was selected as the target animal to study the cysteamine toxicity for one week and growth promotion effects for 60 or 56 days in Ji Mei University fishery experimental station. Results of the present study were as follows:1. Two acute toxicity tests were conducted to investigate the toxicity of CSH to Japanese flounder by intraperitoneal injection (ip) or oral perfusion (po). The results showed that the toxic symptoms of Japanese flounder were obvious under different CSH administration. The 96h medial lethal dose of CSH by ip was 263.6mg/kg BW, and the safe dose was 26.36 mg/kg BW; the 96h medial lethal dose of CSH by po was 1754.7mg/kg BW, and the safe dose was 175.47mg/kg BW.2. A subacute toxicity test was conducted to investigate the effects of CSH on plasma biochemical indices of Japanese flounder by intraperitonal injection. The results showed that the plasma GLU concentration of Japanese flounder significantly increased, while the plasma BUN concentration significantly decreased as compared with the control after 2 hours of intraperitoneal injection of 100mg/kg BW CSH. Plasma GOT activity increased but GPT activity reduced slightly along with the extension of CSH time.3. An experiment was conducted to estimated the effect of different CSH levels (0, 300, 600, 900, 1200 and 1500mg/kg respectively) in practical diets on growth performance and blood biochemical indices of Japanese flounder. The results showed that weight gain rate decreased slightly while the feed conversion ratio increased slightly along with the increase of CSH levels during the feeding period of 0 to 20 days, and the fish fed the diet at the level of 1500mg/kg appeared significant difference compared with the control (P <0.05); Weight gain rate increased slightly while the feed conversion ratio decreased slightly along with the increase of CSH levels during the feeding period of 21 to 40 days, and the values of the two indices at the levels of 900, 1200, 1500 mg/kg were achieved significantly compared with the control (P <0.05). Weight gain rate of Japanese flounder decreased slightly while the feed conversion ratio increased slightly along with the increase of CSH level during the feeding period of 41 to 60 days, and the fish fed the diets at the levels of 1200, 1500 mg/kg appeared significant difference compared with the control (P <0.05). Weight gain rate of each test group increased slightly while the feed conversion ratio decreased slightly along with the increase of CSH level during the whole feeding period of 60 days, but the difference was not significant between treatments (P> 0.05).Along with the increase of CSH levels in diets, the serum hormone levels of Japanese flounder of each test group did not change significantly at day 20, 40 and 60 (P> 0.05). The serum indices such as GLU, BUN, GPT, GOT for Japanese flounder among treated groups showed no significant change at the end of the experiment (P> 0.05).4. A study was carried out to evaluate the effect of 900mg/kg CSH supplement in diets on growth performance and plasma biochemical indices of Japanese flounder at different animal and plant ratios (4:1, 3:1, 2:1 and 1:1 respectively) for a feeding period of 56 days. The results showed that the final body weight, weight gain rate and hepatopancrea somatic index of Japanese flounder in each test group decreased while the feed conversion ratio increased compared with the corresponding control group, but the difference between CSH group and control was not significant (P>0.05). The condition factor of fish fed the diet with A/P ratio of 2:1 significantly increased by 10.31% compared with the corresponding control group (P<0.05), but the fish fed the diet with A/P ratio of 1:1 markedly reduced by 10.48% (P<0.05)。The body lipid and protein content of Japanese flounder of the test groups increased slightly while body moisture decreased slightly compared with the control with the diet at the A/P ratio of 4:1 (P>0.05), however the body ash content significantly decreased by 7.30% compared with the control (P<0.05); The body moisture and lipid content of the test groups decreased slightly while the body protein and ash content increased slightly compared with the control with the diet at the A/P ratio of 3:1 (P>0.05); The body moisture and ash content in test groups decreased slightly while the body protein and lipid increased slightly compared with the control with the diet at the A/P ratio of 2:1 (P>0.05); The body moisture and ash content in test groups decreased slightly while the body protein and lipid content increased slightly compared with the control with the diet at the A/P ratio of 1:1, but no difference between CSH and control treatments was observed (P>0.05).Plasma BUN content, GOT and GPT activities of Japanese flounder in test groups did not showed significant difference compared with the corresponding control (P>0.05). The plasma GLU content of Japanese flounder fed the diets with the A/P ratio 4:1and 1:1 significantly decreased compared with the corresponding control (P<0.05).
|
PDF Full Text Request