| In order to find out the optimal feeding frequency of factory plantation Epinephelus sp,this experiment investigated effects of feeding frequency on growth on growth,physiobiochemical indexes,apparent digestibility and nitrogen phosphorus excretion of Epinephelus malabaricus.1.Selected three kinds of specifications(S:33.37 ± 1.85 g、M:238.99 ± 5.32 g、L:414.79 ± 7.89 g).Each kind of specification,feeding frequency set three gradient.The fish were divided into 3 groups: S2,S3 and S4,which were fed at 2,3and 4 times every day and M1,M2 and M3,which were fed at 1,2 and 3 times every day and L0.5,L1 and L2,which were fed at 0.5,1 and 2 times every day.Three repeat each feeding frequency.Every times was fed to satiety.After fed of 28 d,56 d,84 d days,fish were sampled to weighing and examine.The results are as follows:1.1 Growth and utilization of feed.In three periods,as feeding frequency increasing,the weight gain rate and special growth rate increased.The weight gain rate,special growth rate,protein efficiency ratio and feed efficiency of S4 significantly higher than that of S2.The weight gain rate,special growth rate,protein efficiency ratio and feed efficiency of M2 significantly higher than that of M1,while M2 and M3 had no significant difference.The weight gain rate,special growth rate,protein efficiency ratio and feed efficiency of L1 significantly higher than that of L0.5,while L1 and L2 had no significant difference.1.2 Antioxidant indices.The T-SOD,GSH-PX,CAT and T-AOC of plasma and liver of S4 significantly higher than that of others,while the liver of S4 significantly lower than that of others.But MDA of the plasma had no significant difference.The T-SOD,GSH-PX and CAT of plasma and liver of M2 significantly higher than that of others,while the MDA significantly lower than that of others.But MDA had no significant difference.The T-SOD,GSH-PX,CAT and T-AOC of plasma and liver of L1 significantly higher than that of L0.5,while the MDA significantly lower than that of L0.5.1.3 Metabolic enzymes.The GOT and GPT of plasma of S4 lower than of others,while liver higher than that of others.The GPT of plasma of M2 lower than that of others,while the GPT and GOT of liver of M2 higher than that of other.But the GOT of liver had no significant difference.The GOT and GPT of plasma of lower than that of others,while the GOT and GPT of liver of L1 higher than that of others.1.4 Digestive enzymes.After 84 d feeding,the digestive enzymes of S,M and L declined with feeding frequency enhanced.The digestive enzymes of plasma and liver of S4,M2 and L1 lower than that of others.1.5 Biochemical indices.The AKP,ACP,TG and T-CHO did not differ significantly among groups of S.The AKP of plasma of M2 significantly higher than that of others,but the ACP、TG and T-CHO of plasma had no significant difference.The AKP of plasma of L1 significantly higher than that of L0.5,but the ACP、TG and T-CHO of plasma had no significant difference.2 Selected three kinds of specifications(S:61.99 ± 3.65 g、M:254.11 ± 3.99 g、L:467.55 ± 12.75 g).Each kind of specification,feeding frequency set three gradient.Three repeat each feeding frequency.Daily feeding amount of S,M and L was daily feeding amount.Still water and aeration.After feeding,0.5 h and 1 h collect water sample to determination TN and TP.Collect feces several times every day to determination apparent digestibility.2.1 Nitrogen and phosphorus emissions.The accumulation of TN and TP of S4 significantly lower than that of S2.The accumulation of TN and TP of M2 significantly lower than that of M1,while M2 and M3 had no significant difference.The accumulation of TN and TP of L1 significantly lower than that of L0.5.2.2 Apparent digestibility.As feeding frequency increasing,the apparent digestibility declined.Apparent digestibility of S had no significant difference.Apparent digestibility of M2 significantly higher than that of M3,but M2 and M1 had no significant difference.Apparent digestibility of L declined significantly.Results of the present study suggest that the optimal feeding frequency of S,M and L was 4 meals/d、2 meals/d and 1 meals/d in the culture of Epinephelus malabaricus... |
