Effect of Vitamin D3 replacement with 1α-hydroxycholecalciferol on the performance of broiler breeder hens

This experiment was carried out to evaluate the effects of 1α-hydroxycholecalciferol as a replacement for cholecalciferol on broiler breeder hen performance. 288 Ross "308" broiler breeder hens at 57 weeks of age were allocated to a randomized complete block design with six treatments and four replications of twelve females and 1 male each. The treatments consisted of 3500Iu/kg vitamin D₃(Control),combination of 3340IU D₃+10 g/Ton 1α(OH)D₃, 3300IU D₃+12.5 g/Ton 1α(OH)D₃, 3260IU D₃+15gr/Ton 1α(OH)D₃, 3180IU D₃+20 g/Ton 1α(OH)D₃ and one additional group was fed no supplemental D₃. The results of this study indicated egg production, egg mass, feed conversion, egg specific gravity, early and late embryo mortality and hatchability of the broiler breeder hens fed the vitamin D₃ deficient basal diet was significantly lower than all other treatments (P<0.05). In addition to egg production, egg mass and feed conversion between treatments were significantly differ, and egg production was significantly lower when added as 20 g/Ton 1α(OH)D₃ as compared to lower levels of the same metabolites and also as compared with the hens fed D₃(P<0.05) , however  no differences were observed in egg weight, egg specific gravity, hatchability, early, middle and late embryo mortality and pip egg between treatments supplemented combination of vitamin D_­3 and 1α(OH)D₃ as compared with D₃ (P>0.05).The result of this experiment indicated that  replacement of 1α(OH)D₃ with D₃ in broiler breeder diets have no beneficial effect on egg production, egg shell quality and hatchability. It seems, that hens are able to metabolize sufficient 1,25(OH)₂D₃ from dietary vitamin D₃ to meet requirement.