Effects And Mechanism Of Eco-diet On Fecal Nitrogen And Microelement Excretion For Growing Pigs

The experiment was conducted to investigate the application effects and mechanism of low-protein balance diet and organic microelement additives on growth promotion and fecal pollution reduction of growing pigs. Three reduced excretion diet was designed and growth performance, blood index and fecal stuff excretion in different groups was measured respectively.A total of120Duroc×Landrace×Yorkshire pigs were divided into4groups randomly and equally. Group I was control group. Group Ⅱ was LPD group, with a lower of Crude Protein level at1.5percentage point and additional Lys, Met and Thr supplemented. Group III was organic microelement group, with some Fe-Gly, Cu-Met and Zn-Met replacing50%ferrous sulfate,50%blue copperas and50%zinc sulphate monohydrate respectively. Group IV was LPD combined with organic microelement group, with additional handling both for group Ⅱ and group Ⅲ. Growth performance, fecal nitrogen excretion, fecal microelement excretion like Cu, Zn, Fe, Mn, blood biochemical index and blood enzymatic activity in each group were measured respectively. Results as follows:1Effects on growth performance of growing pigsADFI in group Ⅱ, group Ⅲ and group Ⅳ was1844.70g/d,1996.21g/d and1814.39g/d, respectively. ADG in group Ⅱ, group Ⅲ and group Ⅳ was720.23g/d,722.12g/d and723.26g/d, respectively; FCR in group Ⅱ, group Ⅲ and group Ⅳ was2.56:1,2.80:1and2.53:1, respectively. There is no significant difference on ADFI, ADG and FCR between groups. However it shows a tendency that growth performance was improved in group Ⅱ, group Ⅲ and group Ⅳ. Compared with control group, economic benefit of group Ⅱ was improved by7.71%and that was improved by9.31%of group Ⅳ.2Effects on fecal nitrogen excretion and fecal microelement excretion of growing pigsFinal fecal nitrogen in group II and group IV was4.15%and3.58%, it was reduced by25.96%(p<0.05) and44.21%(p<0.05) respectively; Fecal copper, fecal zinc and fecal manganese in group III was445.32mg/kg,992.27mg/kg and823.00mg/kg, it was reduced by51.65%(p<0.05),17.36%(p<0.05)和5.61%(p>0.05) respectively, fecal ferrum was4972mg/kg(p>0.05); Fecal copper, fecal zinc and fecal manganese in group IV was501.99mg/kg,798.97mg/kg and831.36mg/kg, it was reduced by45.50%(p<0.05)、33.46%(p<0.05) and4.65%(p>0.05) respectively, fecal ferrum was4396.67mg/kg (p>0.05).3Effects on blood biochemical index of growing pigsThere is no significant difference in serum content of TP, ALB, GLB, A/G, CER, BUN and SI between groups.4Effects on blood enzymatic activity of growing pigs There is also no significant difference in enzymatic activity of ACP, AKP, LDH, ALT, AST and AST/ALT.In conclusion, while keep the growth performance the same level as control group, using LPD can save feed cost, reduce fecal nitrogen excretion and increase economic benefit; using organic microelement additives can reduce fecal copper excretion, fecal zinc excretion and fecal manganese excretion; using LPD combined with organic microelement additives can save feed cost, reduce fecal nitrogen excretion, fecal copper excretion, fecal zinc excretion and fecal manganese excretion and increase economic benefit, and combined diet was superior to LPD and organic microelement additives diet in reducing fecal stuff excretion. Both LPD and combined diet have no difference on fecal ferrum excretion.