Effect Of Nano Cu On Growth Performance And Approach To The Mechanism In Pigs

72 weanling crossbred pigs (duroc ×landrace ×yorkshire) were used to study the effects of nanometer Cu (Nano Cu) on growth performance, serum biochemical parameters, internal secretion indexes, routine nutrients in longissimus and liver, and approach to the mechanism of the effects in pigs.All pigs (10.43±2.08kg initially) were divided into three groups based on demands of feeding trial, each of group included three replicates of 8 pigs each. They were control group and testⅠ(supplemented 20 mg/kg tylosin +100 mg/kg SM2)and testⅡ(supplemented 1500 mg/kg nano Cu). The feeding test continued 139 days.The whole feeding trial included three phases ,the piglets received the basal diet(DE-3.23 Mcal/kg; CP-18.70%), the growing pigs received the basal diet (DE-3.11 Mcal/kg;CP-17.09%) and the finishing pigs received the basal diet (DE-3.06 Mcal/kg;CP-16.02%).All pigs were fed and drinked freely.After feeding trial,six pigs in each treatment were selected based on similar live weight and slaughtered at day 139 ,and samples collected for assay.Sample of serum ,longissimus and liver were collected and stored in frozen state.Concentrations of TP, ALB, SUN, TG, GLU, Ch, P, Ca and activities of ALP, GOT,GPT and SOD in serum were determined. Contents of CE, CP and CA in longissimus and liver were also determined. The results of the feeding trial showed that: (1) Adding nano Cu in piglet's diet increased ADFI by 5.93%(P<0.05); (2)during the finishing phase, adding nano Cu in diet increase ADG by 21.45%(P<0.05) compared with the test group Ⅰ; (3) and F/G decreased by 16.72% compared with control during finishing phase, decreased F/G by 7.50%(P<0.05) during the whole test. Serum biochemical parameters analysis indicated that supplementation with 1500mg/kg nano Cu significantly increase the activities of GPT (P<0.01) and SOD (P<0.05), the concentration of ALB and TP in serum decreased (P<0.01),and the concentration of SUN (P<0.01),TG (P<0.05),Ch (P<0.01),GLU (P<0.05) in serum decreased ,too. Adding nano Cu in pig's diet, had no significantly influence on the concentration of GOT and ALP in serum. It was found that adding nano Cu significantly increased the level of GH(P<0.01) in serum. And consumption of nano Cu decreased the content of INS in serum(P<0.05), but nano Cu had no influence on the content of T3 and T4 in serum.The results obtained from this research implicate that (1) supplemental nanometer copper increased the level of GH which is synthesized and secreted by pituitary,decreased SUN content in serum ,improved protein anabolism and efficiency of feed;(2) nanometer copper increased the activity of SOD in serum and improved the capability of eliminating the harmful ?O2-,which could help pigs health;(3) supplemental nanometer copper can improve the metabolism of fat in body ,could the level of fat in muscles.(4)supplemental tylosin+SM2 increased the pig's mortality.