| The initial feed of Monopterus albus larvae is the main bottleneck of the development of M.albus industry,which seriously limits the large-scale breeding of M.albus larvae.In this paper,the M.albus larvae were taken as the research object.Through the proliferation and culture of the initialanimal bait daphnia,the daphnia was selected as the initial bait of the M.albus in the early stage,and the traditional water earthworm was used as the initial bait of the M.albus to solve the problem of high incidence and low survival rate in the early stage.The suitable artificial compound feed was selected to replace the animal bait to solve the problem of the initial feed of the M.albus seedlings.The main results are as follows :1.Effects of different cultivation methods on the amount of Daphnia in the feed of Monopterus albus seedlingsUsing yeast carbon source as the fertilizer source,water Daphnia was cultured in cement ponds,floating double layer cages,and ponds.The results showed that the yield of Daphnia in pond culture was significantly higher than the other two groups(P<0.05),while the yield of Daphnia in cement pond culture was the lowest and significantly lower than the other two groups(P<0.05).2.Effects of different initial diets on early growth and survival rate of Monopterus albusThe average length and average weight of the M.albus larvae were 3.50 ± 0.08 cm and 0.03 ± 0.0001 g.Water flea and water earthworm were used as initial bait for 24 days.The results showed that the end mean length,end mean weight,weight gain rate,specific growth rate and fullness of M.albus in the water earthworm group were significantly higher than those in the water flea group(P<0.05),and the feed coefficient was significantly lower than that in the water flea group(P<0.05).The survival rate of water flea group was 88.33 ± 3.53%,which was significantly higher than that of water earthworm group(55.86 ± 12.16%,P<0.05).3.Effects of different artificial diets on growth and survival of Monopterus albus larvaeThe average length of the experimental M.albus was 7.57 ± 0.13 cm,and the average weight was 0.37 ± 0.02 g.The feed was three different artificial feeds,which were feed A1(paste),feed A2(particles)and feed A3(particles)for 56 days.The results showed that the final average length,final average weight,weight gain rate,specific growth rate and condition factor of A2 group M.albus were significantly higher than those of the other two groups(P<0.05),and the feed coefficient was significantly lower than that of the other two groups(P<0.05).There was no significant difference in survival rate between groups(P>0.05).4.Effects of different diets on growth,serum biochemical indexes and intestinal morphology of Monopterus albusThe baits selected were earthworm and A2 artificial compound feed.Earthworm group : M.albus average length 9.39 ± 0.10 cm,average weight 0.64 ± 0.02g;compound feed group : average length 9.39 ± 0.20 cm,average weight 0.62 ± 0.02 g,feeding 60 days.The results showed that :(1)The average length,average weight,weight gain rate,specific growth rate and condition factor of the M.albus in the compound feed group were significantly higher than those in the earthworm group(P<0.05),and the feed coefficient was also significantly lower than that in the earthworm group(P<0.05).The survival rate of compound feed group was significantly higher than that of earthworm group.(2)The contents of total protein,cholesterol,triglyceride and low-density lipoprotein in serum of M.albus in compound feed group were significantly lower than those in water earthworm group(P<0.05),while the activities of lysozyme,superoxide dismutase and total antioxidant capacity in serum were significantly higher than those in water earthworm group,and the content of malondialdehyde was significantly lower than that in water earthworm group(P<0.05),and there was no significant difference in all indexes(P>0.05).(3)The intestinal villus height of M.albus in the compound feed group was significantly higher than that of the water earthworm group(P<0.05),and the number of goblet cells in the compound feed group was significantly higher than that of the water earthworm group(P<0.05),but the muscle layer thickness of the compound feed group was significantly lower than that of the water earthworm group(P<0.05).Based on the above research results,it is suggested that Daphnia should be selected as the open animal bait of M.albus in the early stage of seedling.With the development of M.albus,mixed feeding about 30 days ago,and artificial compound feed was gradually added to reduce the amount of Daphnia until all of them were fed with artificial compound feed. |
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