Effect Of 25-Hydroxycholecalciferol When Fed To Ducks

The objective of present study is to determine the effect and optimum level of 25-Hydroxycholecalciferol on beijing duck bone and breast muscle development;and determine the phosphorus sparing effect of 25-hydroxycholecalciferol and Phytase when fed to Beijing Duck.To study the effects of 25-Hydroxycholecalciferol (25-OH-D3) in ducks,2160 1-d-old Beijing ducks were randomly allocated to 12 treatments with 6 replicates of 30 ducks per replicate to investigate the effects of 25-OH-D3(0,35,70 and 105μg/Kg) on live,slaughter performance and bone mineralization in Beijing ducks (1 to 45d of age) fed basal diets containing three levels of vitamin D3 (2 500,3 000 and 3 500IU/kg).The results showed 1) There was no effect on average body weight,weight gain,feed intake and feed conversions fed with 25-OH-D3.The ratio of breast meat increased with increase in concentrations of 25-OH-D3(0,35,70μg/Kg) while decreased significantly(P < 0.05) when fed with 105μg/Kg25-OH-D3 compared to diets with 35,70μg/Kg25-OH-D3.At 14d,the concentration of phosphorus in tibia increased with increase in concentration of 25-OH-D3(0,35,70 and 105μg/Kg)while was significant differences between diets with 25-OH-D370,105μg/Kg and 0,35μg/Kg; 2) At 15 to 35d of age, the weight gain increased significantly(P<0.05)when diets containing 3 000,3 500IU/kg vitamin D3 compared to 2 500 IU/kg vitamin D3.At 14 and 45d of age,the concentration of calcium increased significantly (P< 0.05) when diets containing 3 500IU/kg vitamin D3 compared to 2 500 and 3 OOOIU/kg vitamin D3; 3) At 14 and 45d of age,there were significant effects of interaction between 25-OH-D3 and vitamin D3 on the concentration of calcium,phosphorus (P<0.01) and phosphorus (P <0.05) in tibia respectively.A study was conducted to evaluate 6 phosphorus(P) levels, using diets supplementated with/without 70ug/kg 25-hydroxycholecalciferol (25-OH-D3) and 1500U/g Phytase. Each treatment was assigned to 8 pens of 10 10d of age male Beijing Duckings.At 21 and 35 d growth performance and the mineral content of bone and serum, bone mineralization, bone breaking and litter P were determined. The results showed 1)There was no effect on performance and bone mineralization with decrease in concentrations of P(0.45%,0.4%) while Beijing duck tibia ash and strength decreased significantly(P<0.05) when fed with 0.35% P compared to diets with 0.4% P at 20d.2) Compared to diets with 0.4% P,with the decrease in concentrations of P(0.35%,0.3% and 0.25%) in diets supplemented with 25-OH-D3 and Phytase,the concentration of fece P decreased significantly during the period of 18 to 20d while weight gain(10 to 20d),tibia ash and strength decreased significantly(P<0.01 or P<0.05).3) At 21 to 35d of age,there was no effect on performace and b(?)ne mineralization between groups.Based on above results:1) The optimum adding level of 25-OH-D3 was 70μg/Kg of diet containing 3 OOOIU/kg vitamin D3.2) The optimum requirement of available P was 0.4% or 0.3% when diets supplementated with 70ug/kg 25-hydroxycholecalciferol and 1500U/g Phytase.