title: Evaluation of Relative Bioavailability of 25-Hydroxycholecalciferol to Cholecalciferol for Broiler Chickens.
abstract: This study was conducted to evaluate the relative bioavailability (RBV) of 25-hydroxycholecalciferol (25-OH-D3) to cholecalciferol (vitamin D3) in 1- to 21-d-old broiler chickens fed with calcium (Ca)- and phosphorus (P)-deficient diets. On the day of hatch, 450 female Ross 308 broiler chickens were assigned to nine treatments, with five replicates of ten birds each. The basal diet contained 0.50% Ca and 0.25% non-phytate phosphorus (NPP) and was not supplemented with vitamin D. Vitamin D3 was fed at 0, 2.5, 5.0, 10.0, and 20.0 μg/kg, and 25-OH-D3 was fed at 1.25, 2.5, 5.0, and 10.0 μg/kg. The RBV of 25-OH-D3 was determined using vitamin D3 as the standard source by the slope ratio method. Vitamin D3 and 25-OH-D3 intake was used as the independent variable for regression analysis. The linear relationships between the level of vitamin D3 or 25-OH-D3 and body weight gain (BWG) and the weight, length, ash weight, and the percentage of ash, Ca, and P in femur, tibia, and metatarsus of broiler chickens were observed. Using BWG as the criterion, the RBV value of 25-OH-D3 to vitamin D3 was 1.85. Using the mineralization of the femur, tibia, and metatarsus as criteria, the RBV of 25-OH-D3 to vitamin D3 ranged from 1.82 to 2.45, 1.86 to 2.52, and 1.65 to 2.05, respectively. These data indicate that 25-OH-D3 is approximately 2.03 times as active as vitamin D3 in promoting growth performance and bone mineralization in broiler chicken diets.
authors.affiliation: Department of Animal Science, College of Life Science, Shangqiu Normal University, Shangqiu, Henan 476000, China.
authors.forename: J C
authors.initials: JC
authors.lastname: Han
authors.affiliation: Department of Animal Science, College of Life Science, Shangqiu Normal University, Shangqiu, Henan 476000, China.|College of Animal Husbandry and Veterinary Science, Henan Agricultural University, Zhengzhou, Henan 450002, China.
authors.forename: G H
authors.initials: GH
authors.lastname: Chen
authors.affiliation: Department of Animal Science, College of Life Science, Shangqiu Normal University, Shangqiu, Henan 476000, China.|College of Animal Husbandry and Veterinary Science, Henan Agricultural University, Zhengzhou, Henan 450002, China.
authors.forename: J G
authors.initials: JG
authors.lastname: Wang
authors.affiliation: Department of Animal Science, College of Life Science, Shangqiu Normal University, Shangqiu, Henan 476000, China.|College of Animal Husbandry and Veterinary Science, Henan Agricultural University, Zhengzhou, Henan 450002, China.
authors.forename: J L
authors.initials: JL
authors.lastname: Zhang
authors.affiliation: Department of Animal Science, College of Life Science, Shangqiu Normal University, Shangqiu, Henan 476000, China.
authors.forename: H X
authors.initials: HX
authors.lastname: Qu
authors.affiliation: Department of Animal Science, College of Life Science, Shangqiu Normal University, Shangqiu, Henan 476000, China.
authors.forename: C M
authors.initials: CM
authors.lastname: Zhang
authors.affiliation: Department of Animal Science, College of Life Science, Shangqiu Normal University, Shangqiu, Henan 476000, China.
authors.forename: Y F
authors.initials: YF
authors.lastname: Yan
authors.affiliation: Department of Biotechnology and Animal Science, National Ilan University, I-Lan 26047, Taiwan.
authors.forename: Y H
authors.initials: YH
authors.lastname: Cheng
keywords: 25-Hydroxycholecalciferol; Bone; Broiler Chicken; Cholecalciferol; Growth; Relative Bioavailability