Dietary Optimal Metabolic Energy,Crude Protein,Calcium and Available Phosphorus Levels of Wuqin 10 Meat Ducks Aged from 5 to 9 Weeks
This experiment was conducted to study the effects of dietary formulations with different nutritional lev-els on growth performance,body size indexes,slaughter performance,serum biochemical indexes and nutrient appar-ent availability,to determine the appropriate dietary metabolic energy(ME),crude protein(CP),calcium(Ca)and available phosphorus(AP)levels of Wuqin 10 meat ducks aged from 5 to 9 weeks.A total of 504 Wuqin 10 meat ducks at 28 days of age were randomly divided into 9 groups with 4 replicates per group and 14 ducks per repli-cate.The orthogonal design of L9(34)with 4 factors and 3 levels was applied,and nine experimental diets were for-mulated according to different nutrient levels,including 3 ME levels(12.10,12.50 MJ/kg and 12.90 MJ/kg),3 CP levels(16.5%,18.5%and 20.5%),3 Ca levels(0.60%,0.80%and 1.00%)and 3 AP levels(0.30%,0.40%and 0.50%).Nine groups of ducks were fed for 35 days.The results indicated that:1)dietary ME level significantly affected the average daily feed intake(ADFI),average daily gain(ADG),feed/gain(F/G),semi diver length,body oblique length,shank girth,abdominal fat percentage and skin fat percentage,and serum uric acid(UA),glucose(GLU)and phosphorus(P)concentrations of meat ducks aged from 5 to 9 weeks(P<0.05);2)dietary CP level dramatically influenced the ADFI,ADG,sternal length,body oblique length,chest width,breast muscle percentage,abdominal fat percentage and skin fat percentage,and serum total cholesterol(TC),GLU and P contents of meat ducks aged from 5 to 9 weeks(P<0.05);3)the ADFI,sternal length,shank length,shank girth,body oblique length,semi-diver length,abdominal fat percentage,and serum GLU,Ca and P contents of meat ducks aged from 5 to 9 weeks were markedly affected by dietary Ca level(P<0.05);4)the ADG,F/G,body oblique length,chest width,shank girth,abdominal fat percentage and skin fat percentage,and serum UA and GLU contents of meat ducks aged from 5 to 9 weeks were significantly affected by dietary AP level(P<0.05).Summarily,considering the results of growth performance,body size indexes,slaughter performance and blood biochemical inde-xes obtained from this experiment,the optimal dietary ME,CP,Ca and AP levels of Wuqin 10 meat ducks aged from 5 to 9 weeks were 12.50 MJ/kg,18.5%,0.8%and 0.4%,respectively.