不同投饲率下海参肠粉替代鱼粉水平对许氏平鲉生长和生理健康的影响OACHSSCD

[Objective]This study aims to investigate the effects of feeding rate on the growth and physiological health of Sebastes schlegelii with dietary fish meal replaced by different levels of Apostichopus japonicus intestinal meal,and to provide a scientific theoretical basis for the efficient utilization of fish meal alternative resources and the optimization of precision feeding technology.[Method]A 3×4 two-factor experiment,designing three daily feeding rates(mass fraction 1.5%,3.0%,4.5%)and four substitution levels(mass fraction 0%,1%,2%,3%),was conducted in the cage culture for 7 weeks,each treatment had three replicates,and each replicate contained 20 S.schlegelii with an initial body mass of(127.00±0.50)g.The growth,body composition,non-specific immune indicators,digestive enzymes,and serum metabolism of S.schlegelii were measured.[Result]After an 7 weeks feeding trial,the final bodymass,mass gain rate and specific growth rate all exhibited a trend of initial increase followed by subsequent decrease as the replacement level of A.japonicus intestine meal increased.These growth parameters were significantly higher in the 1%replacement group(192.20 g,55.87%,0.84%/d)than those in the 0%and 3%replacement groups.In contrast,the feed conversion ratio in the 2%replacement group(1.97)was significantly lower than that in the 0%and 3%replacement groups,with no significant difference observed between the 2%and 1%replacement groups.At a daily feeding rate of 4.5%,final body mass,specific growth rate,and protein efficiency ratio(181.77 g,0.73%/d,0.91%)were significantly lower than those at daily feeding rates of 1.5%and 3.0%,while the feed conversion ratio was significantly higher in the 4.5%daily feeding rate group(2.53)compared to the 1.5%and 3.0%daily feeding rate groups.The moisture and ash contents in whole body was unaffected by feeding rates,but the ash content was significantly increased with dietary A.japonicus intestine meal(14.93%).Compared with the 0%replacement group,the crude protein mass fraction in whole fish was significantly decreased in the 1%to 3%replacement groups(51.12%,51.98%,51.38%).The crude lipid content in whole fish was significantly higher in the 1%replacement group(30.15%)than that in all other groups,whereas the crude ash content showed a significant increasing trend and was significantly higher in the 3%replacement group(14.93%)than that in the other groups.An increase in the daily feeding rate from 1.5%to 3.0%had no significant effect on the crude protein and crude lipid mass fraction in whole fish.However,the 4.5%daily feeding rate significantly reduced the crude protein and crude lipid contents in whole fish(51.72%,28.12%).The activities of intestinal trypsin,lipase,and amylase were significantly affected by the dual effects of dietary replacement level and daily feeding rate.Increasing the daily feeding rate from 1.5%to 4.5%led to significant reductions in the activities of these three enzymes(1.13 U/μg,1.62 U/g,1.33 U/mg).As the dietary replacement level increased from 0%to 3%,the activities of trypsin,lipase,and amylase all exhibited an initial increase followed by a subsequent decrease,peaking in the 1%replacement group,where the values(13.87 U/μg,3.57 U/g,2.93 U/mg)were significantly higher than those in the 0%and 3%replacement groups.With the increase in the replacement level of A.japonicus intestine meal,the activity of γ-GT showed an increasing then decreasing trend and peaked at the 2%replacement level(13.56 U/L),being significantly higher than that in all other groups.The concentration of blood urea nitrogen displayed an increasing trend and was significantly higher in the 3%replacement group(1.92 mmol/L)than that in the other groups.3%subsititution level significantly influenced the contents of triglyceride and total cholesterol(2.32,3.58 mmol/L).α=0.05.[Conclusion]Replacing 1%-2%of fish meal with A.japonicusr intestine meal at daily feeding rates of 1.5%-3.0%are more conducive to the growth and health of S.schlegelii.