Effects Of Feeding Rate In Spring And Summer And Intermittent Fasting On The Growth,survival And Health Indicators Of The Hybrid Yellow Catfish "Huang You 1"

In recent years,diseases in yellow catfish have occurred frequently,causing huge economic losses to farmers.Feeding as an important part of economic fish farming,it has been confirmed that it will affect the health of fish;meanwhile,overfeeding is also the main source of pollution in aquaculture water.Therefore,this paper takes the hybrid yellow catfish “Huang you No.1” as the research object,and studying the effects of feeding rate and intermittent fasting on the growth,survival and health indicators of yellow catfish in pond cages.Below are key research findings:(1)In pond cages with a water temperature range of 16.5°C-26.8°C,the survival rate of hybrid yellow catfish about 50.00±0.74 g decreased significantly with the increase of feeding rate between 0,0.5% body weight/d and apparent satiety feeding/d(P<0.05).Final weight,weight gain rate,specific growth rate,and fullness increased significantly with the increase of feeding rate(P<0.05).Observations of liver histological injury features were optimal in 0 feeding rate group,and the comprehensive analysis results of liver function biochemical indicators,intestinal shielding function indicators,and immune function indicators were best in the 0.5%body weight/d feeding rate group.(2)In pond cages with a water temperature range of 26.6°C-33.7°C,the survival rate,liver histological and liver function biochemical indicators of hybrid yellow catfish about 10.00±0.39 g did not change significantly with the increase of feeding rate between 1%,2%,apparent satiety feeding rate(P>0.05),Final body weight,weight gain rate,specific growth rate and feed coefficient increased significantly with the increase of feeding rate(P<0.05).The liver-to-body ratio and fullness decreased significantly and then remained relatively unchanged with the increase of feeding rate(P<0.05).Liver histology and biochemical indexes of liver function had no significant changes with the increase of feeding rate(P>0.05).The results of comprehensive analysis of intestinal shielding function indicators were the best at 2% feeding rate.The results of comprehensive analysis of immune function indicators were worst at 1%feeding rate and there was no significant difference between the other two groups(P>0.05).(3)In pond cages with a water temperature range of 26.6°C-33.7°C,the survival rate of hybrid yellow catfish “Huang you No.1” about 10.00±0.51 g did not change significantly under different intermittent fasting programs(P>0.05),There were no significant differences in final weight,weight gain rate and specific growth rate between the apparent satiety feeding group,and the 7-day satiated and 1-day fasting group,and both were higher than 3-day satiated and 1-day fasting group.There were no significant differences in liver histology,liver function biochemical indicators,intestinal shielding function indicators,and immune function indicators under different intermittent fasting programs(P>0.05).The results of this study showed that no feeding and apparent satiety feeding rate in spring,1% feeding rate and apparent satiety feeding rate in summer will all affect the health of hybrid yellow catfish.7-day satiated and 1-day fasting feeding programs can save feed input under the premise of ensuring optimal growth.Sum up,when the water temperature 16.5°C-26.8°C in spring,it is recommended that 0.5% feeding rate was the appropriate feeding rate for hybrid yellow catfish.when the water temperature 26.6°C-33.7°C in summer,7-day satiated and 1-day fasting is recommended as an appropriate feeding strategy for hybrid yellow catfish.The results of this study provide scenario selection and data reference for the improvement of healthy breeding technology and optimizing the existing hybrid yellow catfish feeding strategy.