Effects of grapefruit juice supplementation on the performance, egg quality, and blood biochemistry of late-phase laying hens

This study investigated the effects of grapefruit juice supplementation on the performance, egg quality, and blood biochemistry of late-phase laying hens. A total of 144 Babcock White laying hens, aged 62 weeks and weighing 1603.05 ± 14.33 g, were divided into six groups. Each group was further divided into four replicates containing six hens each. Grapefruit juice was added to the hens’ drinking water at concentrations of 0% (control), 0.25%, 0.50%, 1.0%, 2.5%, and 5.0% for four weeks. Grapefruit juice supplementation positively affected hen-day egg production and egg mass, but did not affect body weight, feed consumption, feed conversion ratio, or egg weight. The water consumption of the 5.0% group was higher than that of the other groups. Although grapefruit juice supplementation increased the Haugh unit, albumen index, and yolk index values, it decreased the eggshell thickness and egg yolk colour values. Serum glucose levels were lower in the 1.0% and 2.5% groups (134.83 mg/dL and 148.16 mg/dL, respectively) than in the control group (186 mg/dL), and serum immunoglobulin G levels were higher in the 1.0% and 2.5% groups than in the other groups. While the grapefruit juice supplementation increased the total antioxidant capacity of the hens, it reduced their gamma-glutamyl transferase values. No differences were observed between the groups in terms of high-density lipoprotein, low-density lipoprotein, cholesterol, alanine aminotransferase, alkaline phosphatase, or total oxidant status values. The results indicate that providing grapefruit juice to laying hens improves their performance, egg quality, and metabolism, depending on dose.