Effects of dietary taurine supplementation on polyunsaturated fatty acids, cholesterol, and egg quality of egg of hens.

This study aimed to assess the impact of dietary taurine supplementation on egg quality, polyunsaturated fatty acids, and cholesterol contents in egg during the late laying period in hens. A total of 102 44-week-old Roman pink laying hens were randomly divided into six groups, one control group and five treatment groups additionally supplied with 0.01, 0.02, 0.05, 0.1, and 0.2% Taurine (weight/weight). Feed intake and body weight were recorded to calculate production performance, and eggs were collected to analyze egg quality. At the end of the study, 10 laying hens were randomly selected from each group and slaughtered to collect blood, liver, and other samples. The results revealed that 0.05% or 0.1% taurine significantly increased the contents of C18-3n and C18-2n polyunsaturated fatty acids in yolks (p < 0.05). Dietary 0.1% or 0.2% taurine significantly decreased the total cholesterol content (p < 0.05) in egg yolks. Moreover, 0.05, 0.1, and 0.2% taurine significantly reduced the mRNA expression of the cholesterol synthesis rate-limiting enzyme HMGCR and transcription factor SREBP2 in the livers of aged laying hens (p < 0.05), and promoted hepatic cholesterol transporter protein ABCG5 and cholesterol esterase ACAT2 mRNA expression (p < 0.05); 0.2% taurine promoted hepatic bile acid synthesis rate-limiting enzyme CYP7A1 mRNA expression (p < 0.05). Additionally, supplementation with 0.01 to 0.2% taurine significantly increased egg weight, with 0.2% taurine significantly increased egg Albumen height at week 4, with 0.05 and 0.1% taurine significantly increased egg Haugh units at week 12, and with 0.02 to 0.2% taurine decreased yolk color at week 16 (p < 0.05). Supplying 0.05 to 0.2% taurine improved specific aspects of egg quality, enhanced contents of polyunsaturated fatty acids, and reduced egg yolk cholesterol during the late laying period. This study provides scientific evidence for the further taurine use in egg production.