Apparent Metabolizable Energy Of Corn,Soybean Meal,Enzyme-treated Soybean Meal,and Fermented Soybean Meal For Laying Hens

Three experiments were conducted to compare the effect of 2 substitution methods on the determination of apparent metabolizable energy(AME)of corn and soybean meal(SBM)for laying hens,to determine the AME of enzyme-treated soybean meal(ESBM),and fermented soybean meal(FSBM),and conventional soybean meal(CSBM)in laying hens,and to determine the AME and net energy(NE)values of 2 corn samples both stored for 3 years in laying hens with total reference diet substitution method.Exp.1 was aimed to compare 2 substitution types,total reference diet substitution method(TRDSM)and energy-yielding ingredients substitution method(EYISM),in the determination of AME of corn and SBM for laying hens by the reference diet substitution method.Sixty 28-wk-old Hy-Line Brown laying hens were assigned to the 5 diets according to a completely randomized block design.Each of the 5 diets was fed to six replicate cages with 2 birds per cage.Results showed that the AME values of corn obtained using the TRDSM and EYISM were 3,701 and 3,736 kcal/kg(DM)(P=0.637),respectively,and the AME values of SBM were 2,413 and 2,458 kcal/kg(DM),respectively.The 2 substitution types have no effect on AME of corn and SBM.The energy-yielding ingredients substitution method was recommended to be used to determine the AME of ingredients in laying hens.Exp.2 was conducted to evaluate 1 sample of CSBM,1 sample of ESBM,and 3 samples of FSBM from the local market in laying hens using the reference diet substitution method.Seventy-two 32-wk-old Hy-Line Brown laying hens were assigned to the 6 diets according to a completely randomized block design.Each of the 6 diets was fed to six replicate cages with 2 birds per cage.Using the reference diet substitution method,the determined AME values for CSBM,ESBM,FSBM1,FSBM2,and FSBM3 were 2,592,2,801,2,744,2,752,and 2,723 kcal/kg(DM)(P=0.04),respectively.The ESBM,FSBM1,FSBM2,and FSBM3 had 209,152,160,and 131 kcal/kg(DM)greater AME values,respectively,compared with the CSBM.Exp.3 was to determine the AME and net energy(NE)values of 2 corn samples both stored for 3 years in laying hens with total reference diet substitution method.Fifty-four Hy-Line Brown hens at the age of 36 weeks were used.A completely randomized block design was used to evaluate 3 diets in 6 respiratory chambers with 3 birds per chamber with 6 repeat runs per diet.The AME values of corn 1 and corn 2 were 3,485 and 3,675 kcal/kg DM,respectively,and the NE values were 2,575 and 2,693 kcal/kg DM,respectively.The AME values of the 2 stored corn samples were lower than these of fresh corn in Exp.1.The AME and NE values of the 2 corn samples both stored for 3 years were lower than the literature values for fresh corn.In conclusion,the energy-yielding ingredients substitution method was recommended to be used to determine the AME of ingredients in laying hens.The AME and NE values of ESBM and FSBM in the current study were higher than CSBM.The AME and NE values of the 2 corn samples both stored for 3 years were lower than the fresh corn.