To study the effects of microecological preparation(MP)on the production performance,intestinal flora and water quality of grass carp.600 healthy and disease-free grass carp with similar initial weight were selected for the experiment and randomly divided into 4 groups,with 3 replicates in each group and 50 replicates per replicate.Among them,the control group(CON group)grass carp were fed with basic diet,while the other three groups of grass carp were added with 2 g/kg(MP2 group),4 g/kg(MP4 group),and 6g/kg(MP6 group)of microecological preparation to the basic diet,respectively.The experiment lasted for a total of 60 days.The results showed that:(1)Compared with the CON group,the final body weight,weight gain rate,and carcass weight of grass carp in the MP2 and MP4 groups were significantly increased(P＜0.05).(2)Compared with the CON group,the number of lactic acid bacteria in the MP6 group was significantly increased(P＜0.05),while the number of Escherichia coli was significantly reduced(P＜0.05).(3)Compared with the CON group,the concentration of ammonia nitrogen in the water of the MP6 group significantly decreased after 40 days and 60 days(P＜0.05);the nitrite concentrations in the water bodies of the MP2,MP4,and MP6 groups were significantly reduced at 20d,40d,and 60d(P＜0.05);the concentration of hydrogen sulfide in the water of the MP6 group significantly decreased at 20d,40d,and 60d(P＜0.05).Conclusion:Adding medium and low level(2,4 g/kg)microecological preparation to the basic diet can promote the growth of grass carp;Adding high-level(6 g/kg)microecological preparation to basic bait can improve gut microbiota,optimize aquaculture water quality,and reduce harmful substances in water quality.
维普
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