Effect of 1-OH-cholecalciferol supplementation on ileal digestibility of dietary calcium and phosphorus and growth performance of turkey poults

The current study was aimed to investigate the effect of 1-OH-D3 on ileal digestibility of dietary calcium and phosphorus and turkey performance. A total of 225 one-day- old male bronze strain turkey with a mean body weight of 65 g were allocated to 3 treatments with 5 replications (each, 15 birds) for 8 weeks, under a completed randomized design. Diets were adjusted separately for two periods 1-4 and 5-8 weeks of age. The experimental treatments, for the first period were consisted: 1) control, containing D3 (4500 IU/kg) 2) 1-OH-D3 (0.14 gr/kg without D3) 3) 1-OH-D3 (0.07 gr/kg) + D3 (2250 IU/kg) and for the second period of experiment were consisted: 1) control, containing D3 (3500 IU/kg) 2) 1-OH-D3 (0.12 gr/kg) 3) 1-OH-D3 (0.06 gr/kg) + D3 (1750 IU/kg) in the diet. The results showed that no significant differences exist among treatments in turkeys’ body weight, feed intake and feed conversion ratio. However, the use of 1-OH-D3 in treatments 2 and 3 increased the ileal digestibility of calcium and phosphorus and the levels of calcium and phosphorus in plasma and bone, also decreased the activity of alkaline phosphatase in plasma, in compared to the control group (P<0.05). Our findings imply that inclusion 1-OH-D3 to the diet did not affect on growth performance in turkeys. However, it caused to increase absorption and accumulation of calcium and phosphorus in bone. In conclusion, 1-OH-D3 can be used to improve the quality of the turkey bone, alone or in combination with D3