Study On The Application Of Schizochytrium Powder In Laying Hens

This study was to investigate the effects of dietary Schizochytrium powder on the production performance,egg quality,antioxidant function,and fat composition of eggs in laying hens.A total of 1344 healthy Jing Fen No.1 laying hens were randomly divided into4 treatments.There were 12 replicates per treatment and 28 laying hens per replicate.The treatment groups were: control group(basic diet),5% flaxseed group(5% FLA),2.5%flaxseed+0.25% Schizochytrium powder group(2.5% FLA+0.25% SCH),and 0.5%Schizochytrium powder group(0.5% SCH).The prefeeding period is 1 week,and the experiment lasted for 4 weeks.On day 14 and 28 of the experiment,blood and egg samples were collected,hens were slaughtered on day 28.The results were as follows:1 The effect of Schizochytrium powder on the production performance in laying hensDuring days 1-14 and days 15-28,compared with the control group,the FLA and SCH treatments did not affect the feed intake,feed to egg ratio,egg production rate,average egg weight,and egg production of laying hens(P>0.05).Therefore,adding Schizochytrium powder to the diet of laying hens has no negative impact on the production performance of laying hens.2 The effect of Schizochytrium powder on egg quality and texture of cooked eggsOn day 14,compared with the control group,the FLA and SCH treatments had no effects on eggshell thickness,egg shape index,eggshell strength,watermark egg score,egg weight,egg yolk specific gravity,eggshell specific gravity,protein height,egg yolk color,and haugh unit(P>0.05).On day 28,0.5% SCH group the proportion of egg yolk showed a decreasing trend(P=0.082).On day 28 of the experiment,compared with the control group,the texture index of cooked eggs significantly increased with the addition of 2.5% FLA+0.25% SCH,5% FLA,and 0.5% SCH in the diet(P<0.05).Adding 5% FLA and 0.5% SCH to the diet significantly increased the cohesion and viscosity of cooked eggs(P<0.05).However,adhesion score was significantly reduced(P<0.05).Therefore,adding an appropriate proportion of Schizochytrium powder to the diet of laying hens has no negative impact on egg quality,while improving the texture and other indicators of eggs.3 The effect of Schizochytrium powder powder on blood biochemical index of laying hensOn day 14,compared with the control group,the addition of FLA and SCH to the diet did not significantly affect the levels of GLU,Ca,TG,TC,LDL,TB,TP,ALT,ALP,UA,GGT,CK,LDH in the serum of laying hens(P>0.05);The 0.5% SCH treatment increased the HDL content in the serum of laying hens(P<0.05).Adding 5% FLA,2.5%FLA+0.25% SCH,and 0.5% SCH to the diet significantly reduced the AST activity in the serum of laying hens(P<0.05).On day 28,compared with the control group,the addition of FLA and SCH to the diet did not significantly affect the levels of GLU,Ca,TG,TC,TB,TP,ALT,ALP,UA,GGT,CK,LDH in the serum of laying hens(P>0.05).Adding 0.5% SCH to the diet significantly increased the HDL content,decreased the LDL content in the serum of laying hens(P<0.05).The activity of AST in serum of laying hens was decreased with the addition of 5% FLA and 0.5% SCH(P<0.05).Therefore,adding an appropriate proportion of Schizochytrium powder to the diet of laying hens can accelerate the metabolic rate of cholesterol transported back to the liver outside each tissue,reduce the rate of cholesterol deposition in the body tissues,and improve the metabolism of cholesterol in the body.4 The effect of Schizochytrium powder on the antioxidant activity of laying hensOn day 14,compared with the control group,the activities of T-SOD and GSH-PX in the serum of laying hens fed with 2.5% FLA+0.25% SCH,5% FLA,and 0.5% SCH were significantly increased(P<0.05).Meanwhile,the content of MDA was significantly decreased(P<0.05).On day 28,compared with the control group,the activities of T-SOD,GSH-PX,and CAT,as well as T-AOC in the serum of laying hens fed with 2.5% FLA+0.25% SCH,5%FLA,and 0.5% SCH were significantly increased(P<0.05).Meanwhile,the MDA concentration was significantly reduced(P<0.05).The activity of T-SOD,CAT,and T-AOC in the liver of laying hens was significantly increased(P<0.05).However,the effect on the activity of GSH-PX and MDA in the liver of laying hens was not significant(P>0.05).Therefore,adding Schizochytrium powder to the diet of laying hens can enhance the antioxidant capacity of their serum and liver.5 The effect of Schizochytrium powder on the activity of lipid related metabolic enzymes in the liver of laying hensCompared with the control group,the addition of 2.5% FLA+0.25% SCH,5% FLA,and 0.5% SCH in the diet had was significantly reduced in the activity of FAS in liver of laying hens(P<0.05).And the activity HSL was significantly increased(P<0.05).Therefore,the addition of Schizochyte powder to the diet of laying hens can significantly reduce FAS enzyme activity and enhance HSL enzyme activity,thereby regulating the activity of liver fat metabolism related enzymes.6 The effect of Schizochytrium powder on the fatty acid composition of eggs(1)The egg fatty acid composition on day 14Compared with the control group,C15:0 and C20:0(arachidic acid)in the diet supplemented with FLA and SCH yolks had a downward trend(P<0.1);The contents of C16:0(palmitic acid),C18:2n6c(linoleic acid),C20:1(arachidonic acid),C20:2,C20:4n6(AA),C24:1n9,SFA,n-6 PUFA,n-6/n-3 were significantly reduced(P<0.05);Meanwhile,SFA and n-3 PUFA significantly increased(P<0.05).(2)The egg fatty acid composition on day 28Compared with the control group,the contents of C16:0(palmitic acid),C18:2n6c(linoleic acid),C20:2(arachidic acid),C18:2n6c(linoleic acid),C20:0(arachidic acid),C20:2,C20:4n6(AA),C24:0(xylic acid),C24:1n9,SFA,n-6 PUFA,n-6/n-3 in the diet supplemented with FLA and SCH yolks were significantly reduced(P<0.05);The content of C20:5n3(EPA),C22:6n3(DHA),USFA,and n-3 PUFA significantly increased(P<0.05).(3)The content of fatty acid in eggsOn day 14,compared with the control group,the content of ALA,EPA,DHA,and n-3PUFA in whole eggs with 2.5% FLA+0.25% SCH,5% FLA were significantly increased(P<0.05).On day 28,The addition of 5% FLA significantly increased the ALA content in whole eggs(P<0.05).In whole eggs with 2.5% FLA+0.25% SCH,5% FLA,and 0.5% SCH the content of EPA,DHA,and n-3 PUFA was increased compared with the control group(P<0.05).In conclusion,adding different levels of Schizochytrium powder in the feed has no effect on the production performance of laying hens,could improve the antioxidant capacity,modulate the activity of fat metabolism related enzymes in liver.Dietary inclusion of 0.5% SCH could increase the content of DHA and EPA in eggs,and the DHA content in the whole egg deposits around 14 days,which could be used for producing DHA enriched eggs.