Net Energy Prediction Of Plant Protein Ingredients To Growing Pigs

Seven experiments were conducted to determine the net energy(NE)of soybean meal(SBM,n =22),expeller-press rapeseed meal(EP-RSM,n = 3),solvent-extracted rapeseed meal(SE-RSM,n =5),full-fat rice bran(FFRB,n = 1),corn germ meal(CGM,n = 1),corn gluten feed(CGF,n = 1),peanut meal(PNM,n = 1)and sunflower meal(SFM,n = 1)and to develop and validate the prediction equations for NE of protein ingredients.In Exp.1,twenty-two SBM produced from soybeans from China(n = 6),USA(n = 6),Brazil(n = 7)or Argentina(n = 3)were determined the digestible(DE),metabolizable(ME)energy and NE and prediction equations for DE and ME in SBM were established.Sixty-nine barrows(Initial BW = 53.1 ± 3.7 kg)were allotted to 1 of 23 diets according to a completely randomized design during two successive periods.The 23 diets included 1 corn basal diet and 22 additional diets were formulated by mixing corn and 24.34%of each source of SBM.The average energy value in SBM from China,USA,Brazil and Argentina were 17.54,17.74,17.45 and 17.92 MJ/kg DM for DE;16.84,17.04,16.70 and 17.38 MJ/kg DM for ME;and 10.00,10.18,9.92 and 10.35 MJ/kg DM for NE,respectively.There are no differences among countries were observed.The best fit equations for SBM were:DE = 38.44-0.43 CF-0.98 GE + 0.11 ADF(R2 = 0.67,P<0.01)and ME =2.74 + 0.97 DE-0.06 CP(R2 = 0.79,P<0.01).In Exp.2,the NE of corn,SBM,EP-RSM and SE-RSM were determined using indirect calorimetry.Twenty-four barrows(Initial BW = 36.4 ± 1.6 kg)were allotted to 1 of 4 diets which included a corn basal diet,a corn-soybean meal basal diet and 2 rapeseed meal diets containing 20%EP-RSM or SE-RSM.The NE of corn,soybean meal,EP-RSM and SE-RSM were 12.46,11.34,11.71 and 8.83 MJ/kg DM,respectively.In Exp.3,total 175 growing pigs(Initial BW = 36.0 ± 5.2 kg)were fed 1 of 5 diets for 28 d,with 5 pigs per pen and 7 pens per treatment in order to validate the measured NE of corn,SBM,EP-RSM and SE-RSM.Diets were a corn-soybean meal diet and 4 diets including 10 or 20%EP-RSM and 10 or 20%SE-RSM.The NE measured in Exp.2 was confirmed by results of Exp.3 with comparable caloric efficiencies of NE for all diets.In Exp.4,the NE for another rapeseed meal samples(EP-RSM,2 samples;SE-RSM,3 samples)were determined and then equations to predict the NE of rapeseed meal were established according to the results of Exp.2 and 4.Thirty-six growing barrows(Initial BW = 41.1 ± 2.2 kg)were allotted into 6 diets comprising 1 corn-soybean meal basal diet and 5 diets containing 19.50%rapeseed meal.The best fit equation for NE of rapeseed meal was NE = 1.14 DE + 0.46 CP-25.24(R2 = 0.96,P<0.01).In Exp.5,the NE of FFRB,CGM,CGF,PNM and SFM were determined and then equations to predict the NE of protein ingredients were established according to the results of Exp.2,4,5 and our previous NE work.Twelve barrows(Initial BW = 32.4 ±3.3 kg)were allotted to a replicated 3×6 Youden square design with 3 successive periods and 6 diets.In each square,there was one corn-soybean meal basal diet and 5 test diets containing 29.25%FFRB,29.25%CGM,24.38%CGF,19.50%PNM,or 29.25%SFM.The NE of FFRB,CGM,CGF,PNM and SFM were 12.33,8.75,7.51,10.79 and 6.49 MJ/kg DM,respectively.The best fit equation for NE of protein ingredients was NE = 0.75 DE + 0.043 ADF-2.18(R2 = 0.89,P<0.01).In Exp.6,twenty-four barrows(Initial BW = 48.8 ± 1.8 kg)were allotted to 1 of 4 diets comprising 1 corn-soybean meal basal diet and 3 diets containing 30%DDGS,20%SE-RSM and 30%SFM in order to determine the DE and ME and predicted the NE of the DDGS,SE-RSM and SFM.The NE of DDGS,SE-RSM and SFM were 9.56,8.20 and 6.54 MJ/kg DM,respectively.In Exp.7,144 growing pigs(Initial BW = 52.2 ± 6.0kg)were fed 1 of 4 diets for 56 d,with 4 pigs per pen and 9 pens per treatment in order to validate the NE prediction equation for protein ingredients.The NE prediction equation for protein ingredients was confirmed by growth trial with comparable caloric efficiencies of NE for ADG or carcass ADG and carcass ADG of lean.In conclusion,the NE of protein ingredients is variable,the NE of soybean meal,EP-RSM,PNM and high-oil corn DDGS were greater than NE of SE-RSM and SFM.The DE,ME,EE and fiber can accurately predicte the NE of protein ingredients for growing pigs.