Effects Of Interaction Between Vitamin A And Vitamin D On Growth Performance, Immune Functions And Metabolism Of Calcium And Phosphorous In Broilers

The experiment was conducted to elucidate the effects of interaction between vitamin A and vitamin D on growth performance, immune functions and metabolism of calcium and phosphoros in broilers. 384 8-day-old AA male broilers with similar body weight were randomly allotted into 16 treatments with 3 replicates in each treatment, with 8 broiler in each replicate. Broilers were fed four levels of dietary vitamin A (1,500 ,3000, 15000, and 45000IU/kg) and four levels of vitamin D ( 500, 1,00, 2,500, and 5000 IU/kg) in a 4×4×3 factorial arrangement. . The results showed as follows:1. Diet containing vitamin A 3000 IU/kg would result in the best growth rate, and diet containing vitamin A 15000 IU/kg would result in the best immune function, and diet containing vitamin A 45000IU/kg would result in a significant decrease in growth performance and immune function of broilers.2. While dietary vitamin A level was 3000IU/kg , the serum vitamin A and vitamin E concentrations were stable. While dietary vitamin A levels was 15000 and 45000IU/kg repectively , vitamin A concentrations in liver and kidney were significantly increased, the concentrations of vitamin E in serum, kidney and liver were decreased .3. While dietary vitamin A level was 45000IU/kg , the bone ash content, bone calcium content , BMD (bone mineral density) ,and AKP (Alkaline Phosphatase) activity of serum were decreased. Phosphorus content in bone was significantly increased. While dietary vitamin A levels was 15000IU/kg, the content of bone calcium had the tendency to be decreased, the content of bone phosphorus was increased, AKP activity activity in serum had the tendency to be decreased.4. While dietary vitamin D level was 1250IU/kg, growth performance and immune functions in broilers were the best . While dietary vitamin D level was 2500 or 5000IU/kg, the growth performance had a tendency to be decreased . While dietary vitamin D level was 5000IU/kg, the immune functions of broilers wees decreased.5. While dietary vitamin D level was 5000IU/kg, bone calcium concentraton and BMD had a tendency to be increased, and calcium and phosphorus contents in serum were also higher .