Figure 4.

Vitamin D metabolite plasma concentrations of 35 d broiler chickens fed different levels of calcium with or without 1-alpha-hydroxycholecalciferol supplementation (D₃ + 1α;D₃, respectively). (A) 24,25-dihydroxycholecalciferol (24,25-(OH)₂-D₃) (B) 25-hydroxycholecalciferol (25-OH-D₃) (C) Cholecalciferol (Vitamin D₃) (D) Comparison of relative concentration between each vitamin D₃ metabolite between D₃ and D₃ + 1α groups; diagonal patterned bars denote D₃ and solid bars denote D₃ + 1α. 1α supplementation effect with 25-OH-D₃. Interaction between calcium inclusion and 1α supplementation with plasma vitamin D₃. Line graphs show means ± standard error means [n = 3; General linear models (GLM), *p < 0.05; ***p ≤ 0.0001].