The objective of this experiment was to determine the effect of supplementation of hot melt extrusion (HME) processed Zn sulfate on growth performance, nutrients digestibility, small intestinal morphology and excretion of Zn in weanling pigs. A total of 200 piglets of mixed sex randomly allotted to four treatments on the basis of initial BW (7.15±0.81 kg). There were five replicates in each treatment with 10 pigs per replicate. The experimental treatments consisted of: 1) basal diet containing ZnSO4; 2) basal diet containing Zn-Methionine (ZnMet); 3) basal diet containing low level of nano-Zn as HME (ZnHME50); 4) basal diet containing medium level of nano-Zn as HME ZnSO4 (Zn-HME75). The average daily gain was improved by the ZnMet and ZnHME75 compared with the pigs fed ZnSO4 supplemented diets (p=0.009). Moreover, ZnHME75 and ZnMet affected on the ATTD of CP during phase 2 (p=0.014). The villus height (VH) was affected by increasing when pigs fed diets supplemented the ZnHME75 (P=0.044). The pigs fed diets supplemented ZnHME50 had significantly the lowest (p=0.037) Zn content in liver compared with other treatments. The Zn content in the feces was significantly higher (p<0.001) in ZnSO4 and ZnMet compared with ZnHME50 or ZnHME75. In conclusion, it could be concluded that dietary Zn can be reduced by 25% with ZnHME without any detrimental effect on performance of weanling pigs.

Background : Zinc (Zn) is one of dietary micronutrients and it is second highest trace element in the body. Over 95% of Zn is located in the cells, but its dominant storage site is absent in the body. Deficiency of Zn may result in anorexia, dysgeusia, dysosmia, skin rash, infection, alopecia, growth failure, and impaired wound healing. Therefore, adequate supplementation of Zn is very important to maintain normal physiological conditions. Methods and Results : Zinc sulfate monohydrate (ZnSO4)-loaded nanocomposites (NCs) were fabricated by using a hot-melt extruder (HME) system. Soluplus (SP) was adopted as an amphiphilic polymer matrix for HME processing. The micro-size of ZnSO4 dispersion was reduced to nano-size by HME processing with the use of SP. ZnSO4 could be homogeneously dispersed in SP through HME processing. ZnSO4/SP NCs with a 75 ㎚ mean diameter, a 0.1 polydispersity index, and a -1 mV zeta potential value were prepared. The physicochemical properties of ZnSO4/SP NCs and the existence of SP in ZnSO4/SP NCs were further investigated by solid-state studies. Nano-size range of ZnSO4/SP NC dispersion was maintained in the simulated gastrointestinal environments (pH 1.2 and 6.8 media). No severe toxicity in intestinal epithelium after oral administration of ZnSO4/SP NCs (at 100 ㎎/㎏ dose of ZnSO4, single dosing) was observed in rats. Conclusion : These results imply that developed ZnSO4/SP NC can be used as a promising nano-sized zinc supplement formulation. In addition, developed HME technology can be widely applied to fabricate nano formulations of inorganic materials.