Effect of cholecalciferol (D3) replacement with 1alpha-hydroxycholecalciferol on broiler breeder hen’s performance

This experiment was carried out to compare the effects of 1?-hydroxy cholecalciferol replacement with cholecalciferol on broiler breeder hen’s performance. 288 Ross"308" broiler breeder hens at 57 weeks of age were allocated to a randomized complete design with six treatments and four replication of twelve females and 1 male each. Treatments include: 3500 IU/kg vitamin D3 (T1), 3340 (T2), 3300 (T3), 3260 and 3180 IU D3 (T5). The incomplete levels of the vitamin D3 in T2, T3, T4 and T5 supplemented by adding 1?(OH)D3 to the diets at levels 10, 12.5, 15 and 20 gr/ton, respectively and treatment with no D3 supplementation. Results showed, compared to lower levels of the same metabolites and also as compared with the hens fed D3, significant reduction in egg production when 20 g/Ton 1?(OH)D3 was added in diet; however, no differences were observed in egg weight, egg specific gravity, hatchability, early, middle and late embryo mortality and piped egg, plasma calcium and phosphorous concentration and tibia ash between treatments supplemented with combination of vitamin D3 and 1?(OH)D3 as compared with D3. The hens fed diet without supplement vitamin D showed significant decrease in egg production and egg mass, egg specific gravity, hatchability and significant increase in feed conversion ratio and early and late embryonic mortality, without any effect on other traits. In conclusion, replacement of 1?(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.