Effect of anti-fibroblast growth factor 23 antibody on phosphate and calcium metabolism in adenine gavaged laying hens.

Dietary factors such as adenine have been linked to phosphate-calcium metabolism disturbance and adverse productive outcomes. Anti-fibroblast growth factor 23 (FGF-23) antibody has been proposed to ameliorate adenine-induced abnormal FGF23/phosphate metabolism. This experiment was conducted to investigate the application of anti-FGF-23 antibody in adenine-gavaged laying hens. Single Comb White Leghorn laying hens with (n = 10) or without (control group, n = 10) systemic anti-FGF-23 antibody were orally gavaged with adenine (600 mg/hen/D) for 21 consecutive days. Adenine gavage increased (P ≤ 0.01) plasma phosphate and calcium levels and tended to increase (0.05 < P ≤ 0.1) plasma 1,25-dihydroxy-cholecalciferol [1,25(OH)2D3] level of hens without FGF-23 antibody. In hen with anti-FGF-23 antibody, adenine gavage increased (P ≤ 0.01) body weight and plasma calcium level and decreased (P ≤ 0.05) plasma FGF-23 level. Feed intake of hens in both treatments was suddenly decreased (control hens decreased from 111 to 55 g, P ≤ 0.01; anti-FGF-23 hens decreased from 96 to 46 g, P ≤ 0.01) 10 D after adenine gavage. Anti-FGF-23 antibody tended to increase (0.05 < P ≤ 0.1) plasma phosphorus level of hens before adenine gavage, interestingly, and decreased (P ≤ 0.01) plasma FGF-23 level and kidney index (% of body weight) of hens after adenine gavage. In conclusion, anti-FGF-23 antibody might be used (before or in the early stage) to delay the development of adenine-induced abnormal FGF23/phosphate metabolism. This is the first study to investigate the FGF-23 status in chickens suffering from dietary factors which may cause abnormal renal phosphate resorption.