%0 Journal Article %T Effects of 1α-OH-D3 on Broiler Chickens, Performance %J Iranian Journal of animal Science %I پردیس کشاورزی و منابع طبیعی دانشگاه تهران %Z 2008-4773 %A CHAKSARI, Iman %A ZAGHARI, Mojtaba %A KHALAJI, Saeed %D 2013 %\ 05/22/2013 %V 44 %N 1 %P 23-33 %! Effects of 1α-OH-D3 on Broiler Chickens, Performance %K 1α-OH-D3 %K Cholecalciferol %K Microbial phytase %K Broiler Chicken %K performance %R 10.22059/ijas.2013.32128 %X An experiment was conducted to evaluate the effects of 1α-OH-D3 either with or withoutCholecalciferol, microbial phytase as well as different levels of dietary calcium, and phosphorus onbroiler chickens, performance. A number of 576 male broiler chickens (Ross 308) were made use of ina completely randomized design of a factorial arrangement (3×2×2×3), comprised of 36 treatments, 4replicates of 4 chicks in each battery cage. Factors included three levels of 1α-OH-D3 (0, 5 and 10μg/kg), two levels of Cholecalciferol (0 and 5000 ICU/kg), two levels of microbial phytase (0 and 500FTU/kg), as well as three levels of Ca and phosphorus (100, 75 and 50% of Ross broiler nutritionrecommendation values). Dietary treatments were implemented within an age interval of from 1 to 42days. Supplementation of diets of 5 and 10 μg/kg of 1α-OH-D3 reduced body weight and feed intake at7, 35 and 42d (P<0.01; P<0.05). Supplementation of 500 FTU/kg of Phytase enzyme in the dietincreased body weight at 7 and 14 days (P<0.05). Interaction between 1α-OH-D3 and phytase on feedconversion ratio was significant (P<0.01), in a way that addition of 500 FTU/kg of Phytase to dietcontaining 5 μg/kg of 1α-OH-D3 improved feed conversion ratio at 28d (P≤0.01). 1α-OH-D3supplementation increased tibia breaking force, linearly (P<0.01). Results indicated that addition of1α-OH-D3 to broiler chickens, diets alleviates the risk of tibial dyschondroplasia incidence. Yet, theappropriate recommended dosage needs to be further investigated. %U https://ijas.ut.ac.ir/article_32128_7ca0de1311fb24abf7500966fd58f0e0.pdf