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

The experiment was conducted to determine the effects and interaction of feeding different levels of VA and vitamin E on growth performance, immune functions and metabolism of calcium and phosphoros in broiler chicks. 384 1-day-old broilers with similar body weight were randomly allotted into 16 treatments with 3 replicates in each treatment, with 8 broilers in each replicate. Broilers were fed four levels of dietary VA (1500, 3000, 15000, and 45000IU/kg) and four levels of vitamin E ( 5, 15, 150, and 1500 IU/kg) in a 4×4 factorial arrangement. The results showed as follows:1. The addition of 1500 ,3000IU/kg VA would result in better growth rate, and 3000 IU/kg VA would be the best ; the addition of 15000, 45000 IU/kg VA would stimulate cell immune functions of broilers but decrease the growth performance.2. The addition of 5, 15 IU/kg VE would result in better growth rate and 150, 1500 IU/kg VE would result in lowert growth rate . The addition of 15, 150 IU/kg VE would result in better immune functions and 5, 1500 IU/kg VE would result in lower immune functions.3. The interaction between A and E was significant for immune function , serum VA and VE concerntrations and liver , kidney VE concerntrations in broilers. The addition of 15000 and 45000 IU/kg VA would contradict with VE; the addition of 5, 15 and 150IU/kg VE would cooperate with VA, but would contradict with VA by 1500 IU/kg of VE in the diet, especially with high level VA.4. Feeding the high levels of VA ( 45000IU/kg) decreased the tibia ash content, tibia calcium content , tibia mineral density and decreased AKP (Alkaline Phosphatase) activity of serum and the addition of 15000 IU/kg VA would decreased above items to different extent. The addition of 1500 IU/kg VE would tend to increase serum calcium content and tibia mineral density.5. The results suggested that the adequate requirements of dietary VA in broilers was 3000IU/kg, and diet containing VA 15000IU/kg was referred to as marginally excess in VA, and farther validated dietary VA was excess while dietary VA level was 45000IU/kg. Adequate requirements of VE in broilers was 15IU/kg, diet containing VE 150IU/kg was referred to as marginally excess in VE, and dietary VE was excess while dietary VE level was 1500IU/kg. The experiment suggested that addition of 3000 IU/kg VA and 15IU/kg VE in diets of broilers would be the best.