PSIV-2 Use of protected zinc oxide in lower doses in weaned pigs in substitution for the conventional high dose zinc oxide.

摘要

Zinc oxide has been used traditionally for many years in large doses up to 3000mg/kg feed due to its growth enhancing and diarrhea alleviating properties.The present study tested the hypothesis that protected ZnO in lower dose can substitute the high dose conventional ZnO. A total of 150 crossbred [(Landrace x Yorkshire) x Duroc] weaning pigs with an average body weight of 6.48 ± 1.58kg were blocked based on sex and randomly allotted to 1 of 6 dietary treatments [5 pigs per pen; 5 pens per treatment] for a 6-wk trial in two phases.Treatments consisted of basal diet (NC); Basal diet without Zn in mineral premix with either 2500 ppm unprotected ZnO (PC) or 250, 500, 750 and 1000 ppm protected ZnO (PZ1, PZ2, PZ3 and PZ4 respectively). Data were analyzed using pre-planned contrast as well as polynomial contrast statements to test the linear, quadratic and cubic effect of PZ concentration in the diet.Except for G/F ratio in phase 1, the growth performance during phases 1 and 2 as well as apparent total tract nutrient digestibility in pigs fed PZ diets was comparable with PC diet. The serum Zn concentration of pigs fed PC diet was higher (P < 0.05) than PZ during week 1, 3 and 6.The fecal Zn concentrations were higher (P < 0.05) in pigs fed PC diets compared to NC and PZ diets during week 1, 3 and 6.A linear response of PZ dose was observed on fecal Zn concentration. The fecal E.coli counts were higher in PZ than in PC during week 1 and 3. The Lactobacillus counts were higher (P < 0.05) in PZ1 and PZ2 diets than PC diets during week 6.In conclusion; a lower dose of protected ZnO could replace the higher dose of conventional ZnO.