title: Influence of vitamin D3, 1 alpha-hydroxyvitamin D3, and 1,25-dihydroxyvitamin D3 on eggshell quality, tibia strength, and various production parameters in commercial laying hens.
abstract: Four hundred 53-wk-old Hyline W36 laying hens were randomly allocated to 10 treatments. The effects of feeding two vitamin D3 metabolites, 1 alpha-hydroxyvitamin D3 [1 alpha-(OH) D3] and 1,25-dihydroxyvitamin D3 [1,25-(OH)2 D3], each at five dietary levels (0, .75, 1.50, 3.00, and 4.50 micrograms/kg of feed) were determined on eggshell quality and tibia strength in commercial laying hens (Experiment 1). In Experiment 2, 1,440 Hyline W36 65-wk-old laying hens were used to determine the effects of four levels of vitamin D3 (0, 500, 1,000, and 1,500 ICU vitamin D3/kg) and three levels of dietary 1,25-(OH)2 D3 (0, .5, and 1.0 microgram/kg of feed) on eggshell quality, tibia strength, and egg production. In Experiment 1, neither 1,25-(OH)2 D3 nor 1 alpha-(OH) D3 affected eggshell quality or production criteria. Tibia weight was increased by adding either 1,25-(OH)2 D3 or 1 alpha-(OH) D3. In Experiment 2, 1,25-(OH)2 D3 increased percentage of shell, shell weight, and egg breaking strength when 0 ICU D3/kg was fed but had no effect at higher levels of vitamin D3. Egg production, feed consumption, and egg weight were also increased with supplemental 1,25-(OH)2 D3 when 0 ICU D3/kg was fed. Tibia weight and tibia breaking strength were also increased by adding 1,25-(OH)2 D3 to the diet. The commercial laying hen metabolizes sufficient 1,25-(OH)2 D3 from dietary vitamin D3 to maintain shell quality but not enough to maintain tibia strength.
authors.affiliation: Poultry Science Department, Auburn University, Alabama 36849.
authors.forename: T J
authors.initials: TJ
authors.lastname: Frost
authors.forename: D A
authors.initials: DA
authors.lastname: Roland
authors.forename: G G
authors.initials: GG
authors.lastname: Untawale
mesh_terms: D000818:Animals; D002117:Calcitriol / Q000494:pharmacology*; D002118:Calcium / Q000097:blood; D002645:Chickens / Q000254:growth & development / Q000502:physiology*; D002762:Cholecalciferol / Q000494:pharmacology*; D004435:Eating / Q000187:drug effects; D004528:Egg Shell / Q000187:drug effects*; D005260:Female; D006887:Hydroxycholecalciferols / Q000494:pharmacology*; D010058:Oviposition / Q000187:drug effects; D010758:Phosphorus / Q000097:blood; D011897:Random Allocation; D013977:Tibia / Q000187:drug effects
chemical_list: D006887:Hydroxycholecalciferols; D002762:Cholecalciferol; D010758:Phosphorus; D002117:Calcitriol; D002118:Calcium; C008088:alfacalcidol