Effect of dietary calcium on tibial dyschondroplasia. Interaction with light, cholecalciferol, 1,25-dihydroxycholecalciferol, protein, and synthetic zeolite.
A series of experiments was conducted to investigate interactions of dietary calcium levels with ultraviolet light, cholecalciferol (D3), 1,25-dihydroxycholecalciferol [1,25-(OH)2D3], dietary protein, and a synthetic zeolite on the development of tibial dyschondroplasia in broilers. A basal diet low in calcium, high in phosphorus and chloride, and known to promote a high incidence of tibial dyschondroplasia was used. The chicks received ultraviolet radiation from fluorescent lights in addition to 1,100 ICU/kg (27.5 micrograms/kg) of D3 in the basal diet when these were not experimental variables. Regardless of whether the calcium level was low (.65%) or adequate (.95%), the incidence of tibial dyschondroplasia was significantly lower in chicks receiving ultraviolet radiation or dietary vitamin D3 levels well above the required amounts. The addition of 10 micrograms/kg of 1,25-(OH)2D3 to the diet when calcium levels varied from .45 to .95% resulted in a reduction in the incidence of tibial dyschondroplasia and increased tibial bone ash when dietary protein levels were 18 or 22%. The addition of 1% synthetic zeolite to the diet did not influence the incidence of tibial dyschondroplasia when the diet contained widely varying dietary calcium levels (.65 to 1.81%) and .73% phosphorus.
Edwards
H M
HM
Department of Poultry Science, University of Georgia, Athens 30602.
Elliot
M A
MA
Sooncharernying
S
S
D000538:Aluminum Silicates / Q000008:administration & dosage; D000818:Animals; D002117:Calcitriol / Q000008:administration & dosage; D002118:Calcium / Q000008:administration & dosage*; D002645:Chickens; D002762:Cholecalciferol / Q000008:administration & dosage*; D004032:Diet; D004044:Dietary Proteins / Q000008:administration & dosage; D008297:Male; D010009:Osteochondrodysplasias / Q000517:prevention & control / Q000662:veterinary*; D010758:Phosphorus / Q000008:administration & dosage; D011201:Poultry Diseases / Q000517:prevention & control*; D013977:Tibia; D014466:Ultraviolet Rays; D017641:Zeolites
D000538:Aluminum Silicates; D004044:Dietary Proteins; D017641:Zeolites; D002762:Cholecalciferol; D010758:Phosphorus; D002117:Calcitriol; D002118:Calcium