| To investigate the optimum process parameters of extracting essential oil from the star anise fruits of Illicium verum Hook.f by steam distillation,experiment using star anise fruits that was randomly allocated to 4 factors(particle size,soaking time,solid-liquid ratio,distillation time)with 3 levels with the method of orthogonal experiment was conducted to assess extraction efficiency of star anise oil,content of trans-anethole in the oil and extraction yield.The extraction efficiency of star anise oil(SAO)was affected(P < 0.05)by particle size,solid-liquid ratio and distillation time,and the content of trans-anethole of SAO was affected(P < 0.01)by distillation time.The particle size and distillation time had significant effects(P < 0.05)on extraction yield of SAO.Results indicated that the optimum technological parameters were as follows: particle size 40 mesh,soaking 32 h,solid-liquid ratio 1:10,and distillating 3 h as result of extraction rate and yield.To investigate the effects of dietary supplementation of SAO on laying performance,nutrient utilization and antioxidant status of laying hens,a total of 864 Hy-Line brown laying hens at 26 wk of age were randomly allocated to 4 treatments with 6 replicates of 36 birds.Dietary treatments were non-SAO supplementation and supplemented with SAO at the levels of 200,400,and 600 mg/kg diet.The birds were fed the diets for 56 days.All laying hens had significant difference on ADFI in d1 to d56 and tended to have significant egg mass(P = 0.085)in d1 to d28.However,increasing diet concentration of SAO tended to linearly improve(P = 0.062)average egg weight and quadratically increase ADFI(P = 0.081)in d1 to d28.Birds supplemented with SAO had higher(P < 0.05)apparent digestibility(AD)and true digestibility(TD)of CP,OM,Lys,Met,Arg,Thr,Asp,Ser,Glu and Gly than those of control group.Quadratic effects on AD and TD of Lys,Met,Thr,Asp,Ser and Gly were observed(P < 0.05).The quantity of cecum microorganism was similar among treatments.Compared with control group,birds supplemented with SAO improved yolk color and egg nutritional content at d28 and 56 and different times of eggs stored.Inclusion of SAO to diet at the level of 400 mg/kg appeared highest nutrient utilization and egg nutritional content.Supplementation of SAO linearly increased(P < 0.05)activities of total superoxide dismutase(T-SOD)(d28 & d56)and glutathione peroxidase(GSH-PX)(d56)in serum,GSH-PX(d28 & d56)in liver and total antioxidant capacity(T-AOC)(d56)in serum and liver,but linearly reduced(P < 0.05)concentration of malondialdehyde(MDA)(d28 & d56)in liver.Supplementation of SAO linearly increased(P < 0.05)T-SOD activity at d14 and d28,reduced(P < 0.05)MDA concentration in yolk at d42 and d56 of the experiment.Increasing content of SAO linearly increased(P < 0.05)T-SOD activity in yolk of eggs stored at d 0,14,28,42 and 56,decreased(P < 0.05)MDA content of eggs stored at d42 and 56,whether laying hens fed diets for 28 or 56 days.The T-SOD activity and MDA content in yolk of laying hens were affected(P < 0.001)by the eggs stored time whether laying hens fed diets for 28 days or 56 days.Inclusion of star anise oil in diets of laying hens may extend the egg storage time by increasing antioxidant status of egg yolk.Dietary supplementation of SAO enhanced egg nutrient content,nutrient utilization and overall antioxidant status of laying hens in a dose-dependent manner. |
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