Effects Of Haematococcus Pluvialis On Growth,Body Color,Antioxidation,Hepatopancreas And Intestinal Of Procambarus Clarkii

Procambarus clarkii is an important economic shrimp in China,but in its breeding process there are different batches of Crayfish size specifications,different body color and other problems.Haematococcus pluvialis can improve the growth performance of aquatic animals,and rich in astaxanthin,can improve the body color of aquatic animals,improve the antioxidant capacity of aquatic animals.Therefore,this paper aims to determine the appropriate amount of H.pluvialis in P.clarkii feed by supplementing P.clarkii feed with different levels of H.pluvialis,and to provide a scientific basis for the development of functional feed for P.clarkii.The present study was determine the optimal requirement of H.pluvialis in the feed of P.clarkii.Six isonitrogenous and isolipidic(32% protein,6% fat)experimental diets containing 0(H0),0.3%(H0.3),0.6%(H0.6),0.9%(H0.9),1.2%(H1.2)and 1.5%(H1.5)H.pluvialis were designed.A total of 720 healthy and uniform-sized P.clarkii(9.2±0.04 g)were randomly divided into six groups,with three replicates in each group.The P.clarkii were cultured in a cement pond(long 3 m,wide 2 m,deep 1 m).The feeding trial lasted for days.The results are shown as follows:(1)Effects of dietary H.pluvialis supplementary on growth performance,body color and body composition of P.clarkiiThe weight gain rate(WG)and specific growth rate(SGR)of P.clarkii were significantly affected by the dietary H.pluvialis supplementary.The WG and SGR of H0.6group were the highest among all groups(P<0.05).No significant differences of flesh content,feed coefficient and whole-body composition were found among all groups(P<0.05).The condition factor of P.clarkii increased as the H.pluvialis supplementary increased from 0.0 to 0.3%,and then decreased as the H.pluvialis supplementary increased from 0.3 to1.5%.The hepatosomatic index of H1.2 group was the lowest among all groups,while H0 group was the highest.The Salmo Fan,Roche value of body color of P.clarkii increased as the H.pluvialis supplementary increased from 0.0 to 0.9%,and then decreased as the H.pluvialis supplementary increased from 0.9 to 1.5%.Astaxanthin content in shrimp shell and muscle increased as the H.pluvialis supplementary increased from 0.0 to 0.9%,and then decreased as the H.pluvialis supplementary increased from 0.9 to 1.5%.(2)Effects of dietary H.pluvialis supplementary on haemolymph biochemical indexes and antioxidant capacity of P.clarkii.The activities of alanine aminotransferase(ALT)and aspartate aminotransferase(AST)in hemolymph of P.clarkii decreased as the increasing H.pluviali supplementary.Total cholesterol(T-CHO)increased as the H.pluvialis supplementary increased from 0.0 to 0.6%,and then decreased as the H.pluvialis supplementary increased from 0.6 to 1.5%.The total cholesterol content in H0.3,H0.6 and H0.9 groups was significantly higher than that in H0 and H1.2 groups(P<0.05).Triglyceride(TG)increased first and then stabilized.The contents of total protein,albumin and globulin of the hemolymph in H0 group were significantly lower compared to those in the other groups(P<0.05).Lysozyme(LZM)activity first increased and then decreased,and the activity in the H1.2 group was significantly higher than that in the H0 group(P<0.05).Contrary to malondialdehyde(MDA)level,superoxide dismutase(SOD)activity in hemolymph was significantly higher in P.clarkii fed with H.pluviali supplementary compared to group(P<0.05).Glutathione peroxidase(GSH-Px)activity of hemolymph in H1.2 group was significantly higher than that in H0 group(P<0.05).Catalase(CAT)activity of hemolymph in H0.9 and H1.5 groups was significantly higher than that in H0 group(P<0.05).There was no significant difference in total antioxidant capacity(T-AOC)in hemolymph among the groups(P>0.05).The hepatopancreatic MDA content in P.clarkii when fed dietary supplied with H.pluvialis was significantly lower than that in P.clarkii when fed dietary supplied without H.pluvialis(P<0.05).Hepatopancreatic T-AOC first increased and then decreased T-AOC in H0.6 and H0.9 groups was significantly higher than that in H0 group(P<0.05).There was no significant difference in hepatopancreatic SOD activity among all groups(P>0.05).The hepatopancreatic GSH-Px activity of adding group was significantly higher than that of no adding group(P<0.05).Hepatopancreatic CAT activity increased first and then decreased.CAT activity in H0.3 and H0.9 groups was significantly higher than that in H0 group(P<0.05).(3)Effects of dietary H.pluvialis supplementary on hepatopancreatic and intestinal digestive enzymes and structure in P.clarkii.No significant differences of hepatopancreatic digestive enzyme activities were found among H0.3,H0.9,H1.5 groups and H0 group(P>0.05).The hepatopancreatic protease activity in H0.6 and H1.2 groups was significantly lower than that in H0 group(P<0.05).There was no significant difference of hepatopancreatic lipase activity between H0.3 group and H0 group(P>0.05).The hepatopancreatic lipase activity of H0 group was significantly higher than that of the other experimental groups(P<0.05).There was no significant difference in hepatopancreatic amylase activity among all groups(P>0.05).There was no significant difference in intestinal protease activity between H0.3 group and H0 group(P>0.05).The intestinal protease activity of H0 group was significantly higher than that of the other experimental groups(P<0.05).The intestinal lipase activity in H0.9,H1.2 and H1.5groups was significantly lower than that in other groups(P<0.05).There was no significant difference in intestinal amylase activity among groups(P>0.05).There were no pathological changes in hepatopancreatic and intestinal structure of P.clarkii when fed dietary supplied with H.pluvialis.Conclusion:(1)The optimal dietary supplementary of H.pluvialis can improve growth performance and body color,improve the antioxidant capacity in P.clarkii.(2)There were no pathological changes in hepatopancreatic and intestinal structure of P.clarkii when fed dietary supplied with H.pluvialis.(3)The optimal dietary H.pluvialis supplementary of P.clarkii was 0.3-0.6%(astaxanthin content 63.3 mg/kg-126.6mg/kg).