PurposeTo study the effects of tea polyphenols (TP) supplementation on serum lipid indexes, egg white antioxidant capacities, egg yolk cholesterol content and liver lipid metabolism of Changshun green-shell laying hens.
MethodsA total of 240 180-day-old laying hens were selected as experimental animals, which were randomly divided into three treatment groups with 10 replicates in each group, and eight laying hens per replicate. The duration of the experiment was 56 days. The three treatments were as follows: control group (fed with basal diet), 200 mg/kg TP group and 400 mg/kg TP group, which were fed 200 and 400 mg/kg TP based on the basal diet, respectively.
ResultsCompared with the control group, the contents of triglyceride, total cholesterol and low density lipoprotein cholesterol in serum of laying hens of 400 mg/kg TP group were significantly decreased (P<0.05), but the content of serum high density lipoprotein cholesterol was significantly increased (P<0.05); the sulfhydryl content of egg white was significantly increased, while the carbonyl content was significantly decreased (P<0.05). The content of egg yolk cholesterol was significantly decreased in 200 and 400 mg/kg TP groups than those in the control group (P<0.05); and the expression of liver ACC, HMGA and CYP7A1 mRNA were decreased (P<0.05), but the expression of AMPK and LDLR mRNA were increased (P<0.05).
ConclusionDietary supplemented with 400 mg/kg TP could enhance the antioxidant level of egg white, reduce the cholesterol level of egg yolk, and improve the lipid metabolism of serum and liver.
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