Edwards (1989a, 1990) has reported that dietary supplementation of a low Ca diet containing 27.5 µ.g/kg cholecalciferol with 10 µ.g/ kg 1,25-dihydroxy­cholecalciferol [1,25-(0H)iD3] significantly decreased the incidence and severity of tibial dyschondroplasia (TD) and increased tibia bone ash. These studies were the first to suggest that TD may be characteristic of a cholecal­ciferol deficiency in the broiler chicken. Edwards made no attempt to limit maternal ,cholecalciferol reserves of the chicks or the amount of ultraviolet light received by the chickens from the battery brooder fluorescent lights or sunlight. Presumably, the birds were able to meet much of their requirement for cholecalciferol via ultraviolet irradiation of cholecalciferol precursors in the skin... ( To continue your read download the below pdf).

 The effect of flourescent Lights on the development of Tibial Dyschondroplasia and Rickets in Broiler Chickens