Effects Of Sunflower Seed Meal On Laying Performance,Egg Quality,Antioxidant Capacity And Lipid Metabolism Of Laying Ducks

The purpose of this experiment was to study the effect of sunflower seed meal substitute for part of the soybean meal on laying performance,egg quality,antioxidant capacity and lipid metabolism of the Jingjiang Ma Duck.In the experment,a single factor design was adopted and 720 healthy 22-week-old Jingjiang Ma Ducks with initial body weight of(1.45±0.13)kg were randomly assigned into 6 treatments with 6 replicates per treatment and 20 ducks per replicate.Ducks in control group were fed a corn-soybean meal basic diet without sunflower seed meal;ducks in test groups were fed the basic diet supplemented with 4%,8%,12%,16% and20% sunflower seed meal,respectively.The experiment lasted for 16 weeks.Experiment 1: The purpose of this experiment was to study the effects of dietary sunflower seed meal supplemental level on laying performance,egg quality,organ index and jejunal digestive enzyme activity of laying ducks.The results showed that: 1)From 1to 8 week of the experiment,dietary sunflower seed meal supplemental level had no significant effect on the laying performance of laying ducks(P>0.05).From 9 to 12 week of the experiment,the ratio of feed-to-egg in 20% group was significantly higher than that in the control group and 4% group(P<0.05).With the increase of sunflower seed meal supplemental level,the ratio of feed-to-egg showed a significantly increased linear(P=0.004)effect.From 13 to 16 week of the experiment,the average daily feed intake showed a significantly increased linear(P=0.001)effect,the 20% sunflower seed meal group of laying ducks was significantly higher1 than that in the control group and 4%group(P<0.05).The ratio of feed-to-egg in 20% group was significantly higher than that in the control group(P<0.05).The average egg weight of the 16% and 20% groups was significantly lower than that in the control group.With the increase of sunflower seed meal supplemental level,the average egg weight showed a significantly decreased linear(P=0.009)effect.From 1 to 16 week of the experiment,The ratio of feed-to-egg in 20%group was significantly higher than that in the control group(P<0.05).With the increase of sunflower seed meal supplemental level,the ratio of feed-to-egg showed a significantly increased linear(P=0.017)effect.2)Compare with the control group,dietary sunflower seed meal supplemental level significantly decreased yolk color(P<0.05),but had no significant effect on yolk weight,albunim weight,eggshell weight,eggshell strength,eggshell thickness,haugh unit and egg shape index.Yolk color showed a significantly decreased linear(P<0.001)effect with the increase of sunflower seed meal supplemental level.3)The dietary sunflower seed meal level had no significant effect on liver index,intestinal index,Oviduct index,ovarian index,Large yellow follicle weight /ovarian weight and small yellow follicle weight / ovarian weight of laying duck(P>0.05).4)With the increase of sunflower seed meal supplemental level,the activity of laying duck jejunum α-amylase,lipase,trypsin,chymotrypsin decreased linearly(P<0.001).Compared with the control group,the 16% and 20% groups significantly decreased the activity of jejunum α-amylase,trypsin and chymotrypsin(P<0.05),the 20% group significantly decreased the activity of jejunum lipase in laying ducks(P<0.05).Experiment 2: The purpose of this experiment was to study the effect of sunflower seed meal on the plasma、jejunum and liver antioxidant capacity of laying ducks.The results showed that: 1)Compared with the control group,8% and 12% groups significantly increased the plasma GSH-Px activity of laying ducks(P<0.05),and the 20%group significantly decreased the plasma GSH-Px activity(P<0.05).With the increase of sunflower seed meal supplemental level,the plasma GSH-Px activity showed a significantly increased a quadratic(P = 0.042)effect.2)sunflower seed meal had no significant effect on the jejunum,T-AOC,MDA content,GSH-Px and T-SODactivities of laying ducks(P>0.05).3)Compared with the control group,8% and 12% groups significantly decreased the MDA content of the duck liver and significantly increased the liver GSH-Px activity(P<0.05),The activity of liver T-SOD and T-AOC in 20% group decreased significantly(P<0.05).With the increase of sunflower seed meal supplemental level,the activity of T-SOD,GSH-Px and T-AOC in laying duck liver showed a quadratic curve(P<0.001)effect that increased first and then decreased,and the MDA content of the duck liver showed a quadratic curve(P=0.004)effect that decreased first and then increased.4)Compared with the control group,the 4% and 8% sunflower seed meal groups significantly increased the relative expression of CAT and HO-1 m RNA in egg duck liver(P<0.05),and the 12% group significantly increased laying duck liver Nrf2,CAT,HO-1and SOD m RNA relative expression(P<0.05),the 16% group significantly decreased the relative expression of GPX1 m RNA in laying duck liver(P<0.05),the 20% group was significant decreased the relative expression of GPX1 and SOD m RNA in laying duck liver(P<0.05).With the increase of sunflower seed meal supplemental level,the relative expression levels of SOD,CAT and HO-1 m RNA showed a significant quadratic curve(P<0.001)effect that increased first and then decreased.Experiment 3: The purpose of this experiment was to study the effect of sunflowerseed meal supplemental level on lipid metabolism indexes of plasma,liver and yolk,egg yolk fatty acid composition and m RNA expression levels of liver lipid metabolism in laying ducks.The results showed that:1)Compared with the control group,the 8%,12%,16% and 20% sunflower seed meal groups significantly decreased the levels of TG,TC and LDL-C in laying duck plasma(P<0.05),significantly increased Plasma HDL-C content(P<0.05),significantly decreased yolk and liver TC content(P <0.05).The 16%and 20% groups significantly decreased the liver TG content of laying ducks(P<0.05).With the increase of sunflower seed meal supplemental level,plasma TG,TC,LDL-C and yolk,liver TC in laying ducks decreased linearly(P<0.001),and the plasma HDL-C content increased linearly(P<0.001),liver TG The content decreased linearly(P=0.001).2)Sunflower seed meal had no significant effect on the composition of yolk saturated fatty acids(P>0.05),significantly reducing the total monounsaturated fatty acid content(P<0.05)and increasing the total polyunsaturated fatty acid content(P<0.05).With the increase of sunflower seed meal supplemental level,the content of oleic acid(C18: 1)decreased linearly(P<0.001).Sunflower seed meal significantly increased the content of n-6 polyunsaturated fatty acids in yolk(P<0.05),the 12%,16% and 20% groups significantly increased the content of linoleic acid(C18: 2)(P<0.05),the 16% and 20%groups significantly increased the content of eicosadienoic acid(C20: 2)(P<0.05),and the 8%,12%,16% and 20% groups significantly increased the linolenic acid(C18: 3),dihexahexaenoic acid(C22: 6)and n-3 polyunsaturated fatty acids(P<0.05).With the increase of dietary sunflower seed meal supplemental level,the contents of C18: 2,C18:3,C20: 2,C22: 6,n-3 PUFA,n-6 PUFA and Total PUFA in yolk increased linearly(P<0.001).3)Compared with the control group,8%,12%,16% and 20% sunflower seed meal groups significantly increased CYP7A1 m RNA relative expression of laying duck liver(P<0.05),and decreased the m RNA relative expression of HMGCR and SREBP2(P<0.05).8%,12%,16% and 20% groups significantly decreased SREBP1 and ACCα m RNA relative expression of laying duck liver(P<0.001),16% and 20% groups significantly decreased FAS m RNA Relative expression(P<0.05),the 12% group significantly increased CPT1 A m RNA relative expression(P<0.05).In conclusion,sunflower seed meal reduce the yolk color.When the sunflower seed meal supplemental level is less than 16%,it has no unfavorable effect on laying performance and intestinal digestive capacity of laying ducks.8% and 12% sunflower seed meal groups improve the liver antioxidant function of laying duck.When the sunflower seed meal supplemental level is more than 8%,it can promote the lipid metabolism of laying ducks,reduce liver cholesterol and triglyceride content,and promote the deposition of polyunsaturated fatty acids in duck egg yolks.In the erperiment,the appropriate supplemental level of sunflower seed meal is from 8% to 16%.