Dietary supplementation with Eucommia ulmoides improves production performance, egg quality, meat characteristics and physiological status of aging laying hens

The decline in egg production and the gradual physiological deterioration observed during the late-laying period are significant factors contributing to decreased profitability in the poultry industry. This study explores the effects of adding Eucommia ulmoides leaf powder (EULP) to the diet on the production performance and physiological functions of 70-week-old Lohmann laying hens through a 56-day feeding experiment. The results indicated that 4 % fermented Eucommia ulmoides leaf powder (F-EULP) supplementation significantly reduced (p < 0.01) the rates of broken and soft-shelled eggs, and increased (p < 0.05) the egg production rate by 21 %. Furthermore, a 3 % EULP supplementation enhanced yolk color by 0.75 Roche units and egg white viscosity. 4 % F-EULP also decreased (p < 0.001) the drip loss in pectoral and thigh muscles, improved (p < 0.05) the content of essential amino acids (Val, Met, Phe), reduced (p < 0.001) the levels of saturated fatty acids (lauric acid, heptadecanoic acid, heneicosanoic acid, lignoceric acid), and increased (p < 0.05) unsaturated fatty acids (Oleic acid, Linoleic acid, α-Linolenic acid). Additionally, serum total cholesterol (TCHOL) and triglycerides (TRIG) were notably reduced (p < 0.01), accompanied by enhanced hepatic superoxide dismutase (SOD) activity. Network pharmacological analysis verified that active components such as Eucommia ulmoides leaf kaempferol and quercetin might regulate lipid metabolism, antioxidation, and egg-laying performance through core targets such as ESR1 and EGFR. In conclusion, a supplementation level of 4 % F-EULP can be used as the preferred additive level to improve the egg-laying efficiency, meat quality, and overall health of elderly laying hens, providing a feasible nutritional strategy for extending the egg-laying cycle and enhancing the utilization value of culled hens.