title: Effects and interactions of dietary levels of vitamins A and E and cholecalciferol in broiler chickens.
abstract: Four experiments were conducted to determine the effects and interactions of feeding different levels of vitamins A, cholecalciferol (vitamin D3), and E on broiler chicks. In Experiment 1, chicks were fed marginal vitamin D3 (500 IU/kg) and increasing dietary levels of vitamin A (5,000, 10,000, 20,000, 40,000, 80,000, and 160,000 IU/kg). Bone ash was reduced by 10,000 IU/kg of vitamin A in the diet and at vitamin A levels above 20,000 IU/kg of diet body weight was reduced. In Experiment 2, two levels of vitamin A (1,500 and 15,000 IU/kg) and six levels of vitamin E (10, 500, 1,000, 2,500, 5,000, and 10,000 IU/kg) were added to the basal diet. High levels of vitamins A and E significantly (P < 0.001) reduced bone ash. The vitamin A x E interaction was significant (P < or = 0.05) for rickets. In Experiment 3, the same two levels of vitamin A as Experiment 2 and six levels of vitamin D3 (500, 1,000, 1,500, 2,000, 2,500, and 3,000 IU/kg) were added to the basal diet that contained 10,000 IU/kg of vitamin E. Body weight and bone ash were increased by increasing vitamin D3 with a corresponding reduction (P < or = 0.05) in rickets. In Experiment 4, three levels of vitamin A (1,500, 15,000, and 45,000 IU/kg), three levels of vitamin D3 (500, 1,500, and 2,500 IU/kg), and three levels of vitamin E (10, 5,000, and 10,000 IU/kg) were added to the basal diet. Significant negative responses (P < or = 0.05) to increasing dietary vitamin A were observed for bone ash, rickets, and plasma and liver vitamin E. A significant (P < 0.001) increase in bone ash and plasma calcium with a corresponding reduction in rickets was observed by increasing vitamin D3. Increasing dietary vitamin E adversely affected (P < or = 0.01) bone ash, plasma calcium, and plasma and liver vitamin A concentrations. These results indicate the need for making feed with the proper ratios of vitamins A, D3, and E.
authors.affiliation: Department of Poultry Science, University of Georgia, Athens 30602-2772, USA.
authors.forename: A
authors.initials: A
authors.lastname: Aburto
authors.forename: W M
authors.initials: WM
authors.lastname: Britton
mesh_terms: D000818:Animals; D001835:Body Weight; D002118:Calcium / Q000097:blood; D002645:Chickens / Q000502:physiology*; D002762:Cholecalciferol / Q000008:administration & dosage*; D004032:Diet; D004347:Drug Interactions; D008099:Liver / Q000737:chemistry; D008297:Male; D008903:Minerals / Q000378:metabolism; D014801:Vitamin A / Q000008:administration & dosage*; D014810:Vitamin E / Q000008:administration & dosage* / Q000032:analysis / Q000097:blood
chemical_list: D008903:Minerals; D014801:Vitamin A; D014810:Vitamin E; D002762:Cholecalciferol; C028705:bone ash; D002118:Calcium