Evaluation Of Metabolizable Energy Of Corn By-products And The Application Of Corn Gluten Feed In Meat Duck

The objective of this study is firstly to evaluate the metabolizable energy(ME)of corn by-products in meat duck based on the chemical compositions of corn by-products,and metabolic trial.Secondly to investigate the effects of the corn gluten feed at graded levels in diets on growth performance,intestinal development and slaughter performance in meat ducks fed diets.This study included two experiments.Experiment 1:Evaluation of metabolizable energy of corn by-products in meat duckThe study was aimed to evaluate the metabolizable energy of corn by-products(12 samples of corn gluten feed,6 samples of corn germ meal.and 7 samples of DDGS)in Cherry Valley meat duck.and further to establish the prediction equations for ME of corn by-products based on chemical composition.Sixty healthy Cherry Valley ducks(Body weight.BW 3.3±0.3 kg)were used.All ducks were randomly allotted into 6 groups with BW,10 replicates of-1 duck per each group,and one group for endogenous.The TME bioassay described by Sibbald(1976 and 1977)were usd with.the feed deprivation of all birds for 48h prior to force feeding,the amount of forced feed was 2%BW,and the 48h period of excreta collection,while the birds assigned for determination of endogenous losses were 48 h period of excreta collection without any feed force feeding.The results showed that:1)AME,AMEn,TME,TMEn of corn gluten feed were 6.36±1.61、6.58±1.57、7.84±1.54、7.29±1.50 MJ/kg,respectively.AME,AMEn,TME,TMEn of DDGS were 10.79±1.23、10.87±1.34、12.89±1.26、12.03±1.36 MJ/kg.respectively.AME,AMEn.TME.TMEn of corn germ meal were7.87±2.10、7.93±1.93)、9.36±2.07、8.8±1.97 MJ/kg-respectively.2)The optimal regression model of s corn gluten feed.DDGS and corn germ meal were:TMEn=-0.219 NDF+16.940(R2=0.8814,P=0.0017),TMEn=0.191 EE-0.542 CF+15.270(R2=0.92113,P=0.0221)and TMEn=-1.179 CF+21.410(R2=0.7614,P=0.0233).respectively.These results suggested that.there were a wide change of AME,AMEn,TME and TMEn in different types of corn by-porducts.according to Sd and CV,and the prediction equations of TMEn established by chemical compositions of corn by-products were reliable.Experiment 2:Effects of dietary corn gluten feed levels on growth performance,nutrient utilization,intestine growth and qulity of breast meat in meat duck aged from 1 to 56 days.This experiment was conducted to determine the effects of dietary corn gluten feed levels on gowth performance,nutrient utilization,intestine growth and quality of breast meat in meat duck aged from 1 to 56 days.Five isonitrogenous and isocaloric experimental diets contained 0%,5%,10%,15%and 20%corn gluten feed,respectively,were formulated based on digestible amino acid.Each dietary treatment consisted of 8 replicate pens of 18 birds.The experiment included three phases:1-14d,15-35d,36-56d.All birds were free acess to water and feed.The results showed:1)Body weight(14,35d),body weight gain and feed intake(1-14d,15-35d)were decreased in a linearly manner by increasing of dietary corn gluten feed levels(P<0.01),while the feed to gain ratio lineary increased(P<0.05)。2)The relative weight and relative length of duodenum,jejunum and ileum at 14 days of age,and the relative weights of the liver at 14 d and 56 d of age significantly increased(P<0.05)with the addition of corn gluten feed.3)With the increase of dietary corn gluten feed levels,the leg muscle weight and percentage(35d)linearly increased(P<0.05),while eviscerated carcass rate(56d)linearly decreased(P<0.05).Ducks fed diet with 5%corn gluten feed lowered(P<0.05)abdominal fat rate compared with fed other diets.According to these results,we recommended that the addition of corn gluten feed in diets for meat ducks during 1 to 14d,15-35d and 35-56d should be less than 5%,10%and 20%,respectively.