Effects of fermented feed rich in γ-polyglutamic acid on performance,egg quality,serum biochemical parameters and lipid metabolism of laying hens during later laying period
The purpose of this experiment was to investigate the effects of different proportions of fermented feed rich in γ-PGA on production performance,egg quality,serum biochemical indicators,and lipid metabolism in laying hens during later laying period.A total of two hundred and forty 71-week-old Jinghong No.3 laying hens were randomly divided into 4 groups with 4 replicates in each group,and 15 chickens per replicate.The hens in control group were fed a basal diet,and the others in groups of Ⅰ,Ⅱ and Ⅲ were fed the basal diets supplemented with 0.5％,2％and 8％fermented feed rich in γ-PGA replaces parts of the basal diets respectively.The experiment lasted for 28 days after 7 days per-experiment.The results showed that:(1)Compared with the control group,the average egg weight of each experimental group increased,but the increase was not significant(P＞0.05).The rate of damaged and deformed eggs decreased,among them,group Ⅰ dropped 52.6％compared to the control group(P＜0.01).(2)The egg yolk color and eggshell strength of each experimental group showed increasing trends,at the same time,the malondialdehyde content in the egg yolk of group Ⅰ dropped 41.5％compared to the control group(P＜0.01).(3)The total protein,globulin and phosphorus content in each experimental group showed increasing trends,but the differences were not significant(P＞0.05).The serum calcium content in groups Ⅰ and Ⅱ decreased by 16.5％and 22.9％respectively(P＜0.05),and the glucose content in Ⅰ,Ⅱ and Ⅲ group down by 36.6％,19.1％and 17.4％respectively(P＜0.01),in the meantime,the uric acid level had no significant difference(P＞0.05)in each test group.(4)The levels of serum triglyceride(TG),total cholesterol(T-CHO),and low density lipoprotein cholesterol(LDL-C)in each test group decreased,while the content of HDL-C increased,among which,the total cholesterol(T-CHO)and TG levels in group Ⅰ dropped 34.4％and 30.9％respectively(P＜0.05),the HDL-C levels in groups Ⅰ and Ⅱ were 5.13 and 9.31 times as many as those in the control group,respectively(P＜0.05).In conclusion,adding appropriate amount of fermented feed rich in γ-PGA to the diet of laying hens could increase average egg weight,yolk color,egg shell strength and the content of phosphorus in serum,reduce the rate of damaged and deformed eggs,the content of malondialdehyde in the yolk and the serum glucose level,control serum lipid metabolism,maintain serum triglycerides and cholesterol at normal levels in laying hens during the later laying period.Therefore,fermented feed rich in γ-PGA had the potential to be used as a feed additive for laying hens,and the addition level of 0.5％had the best effect from production perspective.
万方数据
维普
