Study Of Zinc Sources On Growing-Finishing Pigs

The study was conducted to investigate the effect of different zinc sources replacing the inorganic zinc on growing-finishing pigs.264DLY crossed growing pigs, averaging about28kg in body weight were randomly divided into control group, trial group Ⅰ,Ⅱ,Ⅲ, Ⅳ and Ⅴ (with4repeats each group and11pigs each repeat),and were respectively fed with control diet(basic diet,the zinc content were100mg/kg in the early period and70mg/kg in late period respectively,100%zinc sulfate),50%Zn-Met2replace100%zinc sulfate,100%Zn-Met2replace100%zinc sulfate,100%Zn-Met replace100%zinc sulfate,100%Zn-Gly2replace100%zinc sulfate,100%zinc fumarate replace100%zinc sulfate. The results show by the following.1. Production performance:There was no significant difference on ADG among the groups in early period (p>0.05). ADG of trial groups increased to some extent compared with control group, especially ADG of group Ⅲ was significantly higher than control group and group Ⅱ (p<0.05). Compared with control group, feed conversion ratio(F/G) of group Ⅰ, Ⅱ,Ⅲ decreased by3.52%,4.41%,1.76%(P>0.05) in early period; and F/G of group Ⅰ,Ⅱ,Ⅲ, Ⅳ decreased by7.50%,2.86%,7.86%,1.79%respectively in late period. In whole trial period, ADG of Group Ⅰ,Ⅱ,Ⅲ, Ⅳ, Ⅴ increased by3.69%, 3.57%,13.86%,6.25%,1.45%respectively, especially ADG of group Ⅲ was significantly higher than control group (p<0.05),there was no significant difference in F/G among groups. But feed efficiency of the group Ⅲ was the best, control group lowest.2. Serum biochemical parameters:Adding different organic zinc replace inorganic zinc in diet can improve serum biochemical parameters in a certain extent, but there was no significant difference.3.Digestibility and absorptivity:There was no significant difference in CP, EE and CF digestibility by using different zinc sources. But compared with control group, group Ⅰ、Ⅱ、Ⅲ、Ⅴ increased by2.52%,4.42%,0.48%,1.50%respectively in CP digestibility(p>0.05). Group Ⅱ was the best in CP and EE digestibility. There was no significant difference in trace elements absorptivity among organic and inorganic zinc. But compared with control group, group Ⅰ increased by5.11%.4. Organization trace elements:There was significant difference in serum Cu and serum zinc between group Ⅲand control group(p<0.05). Group Ⅲ was the highest in serum iron and serum zinc on organization liver and tibia,and There was no significant difference in other organic zinc groups. It is thus clear that adding Zn-Met, Zn-Met2, Zn-Gly2and zinc fumarate to replace inorganic zinc in diet can increase deposition, absorption and utilization of trace elements. Zn-Met(groupⅢ) has the most effect.5. Carcass meat performance:Compared with control group,there had different degrees of improvement on slaughter performance of group Ⅰ, group Ⅱ, groupⅢ, groupⅣ, group Ⅴ. Group Ⅴ was the best, thereafter was group Ⅲ. It is thus clear that using organic zinc replace inorganic zinc can improve pork color on growing-finishing pigs,and Zn-Met(groupⅢ)can increase eye muscle area and water holding capacity.Thus they can improve pork quality.In conclusion, Adding Zn-Met, Zn-Met2, Zn-Gly2to replace inorganic zinc in diet can improve ADG and F/G on growing-finishing pigs. The organic zinc can increase deposition of trace elements in organization. Zn-Met(group Ⅲ) was both the best. Using organic zinc replace inorganic zinc can improve pork color on growing-finishing pigs,and Zn-Met(groupⅢ)can increase eye muscle area and water holding capacity.Thus they can improve pork quality.