Use of coated nano zinc oxide as an additive to improve the zinc excretion and intestinal morphology of growing pigs. (3rd April 2019) - Bai, Miaomiao
Abstract: Two experiments were designed to explore the effects of coated zinc (Zn ) oxide nanoparticles (NZO ) on the diarrhea ratio, antioxidant capacity, intestinal morphology, and zinc excretion in growing pigs. In Exp.1, 270 growing pigs (21.88 ± 0.8 kg initial BW) were allocated to three treatments, each for 30 d: (i) control group (CG ), basal diet containing Zn-free premix + 100 mg Zn/kg from ZnSO4 ; (ii) high Zn (HZN), basal diet containing Zn-free premix + 2, 250 mg Zn/kg from ZnO; (iii) coated nano ZnO (CNZO), basal diet containing Zn-free premix + 100 mg Zn/kg from coated NZO. In Exp.2, 21 crossbred growing pigs (17.04 ± 0.01 kg initial BW) were allocated to three treatments, each for 28 d: (i) HZN, basal diet containing Zn-free premix + 2, 250 mg Zn/kg from ZnO; (ii) low concentration of nano ZnO (LNZO), basal diet containing Zn-free premix + 100 mg Zn/kg from 5% coated NZO material; (iii) high concentration of nano ZnO (HNZO), basal diet containing Zn-free premix + 100 mg Zn/kg from 10% coated NZO material. In Exp. 1, compared with the CG diet, CNZO significantly reduced the diarrhea rate ( P < 0.05) and increased the activities of glutathione peroxidase and superoxide dismutase ( P < 0.05). Compared with HZN, CNZO decreased the activities of serum alanine aminotransferase, and alkaline phosphatase, as well as the fecal zinc concentration ( P < 0.05). In Exp. 2, pigs fed LNZO or HNZO had an increased final BW, average daily weigh and diarrhea rate, and a decreased level of Zn in the plasma, liver, and feces on day 14 compared with the HZN group ( P < 0.05). The villous height and villous height/crypt depth ratio of duodenum were higher ( P < 0.05) in the HZN group than the HNZO group, whereas the higher villous height of jejunum was observed in the LNZO group compared with that in the HNZO group ( P < 0.05). We found that CNZO (100 mg/kg Zn) could improve the antioxidant capacity and reduce fecal Zn emission. However, the diarrhea rate was not effectively suppressed when compared with the HNZO supplementation. Furthermore, coated NZO material of 5% concentration is more effective in improving the morphology of intestinal villus.