This study was to investigate effects of
zinc oxide nanoparticle (Nano-ZnO) on growth, immunity, intestinal morphology and function of
intrauterine growth retardation (IUGR) finishing pigs. Six normal
birth weight (NBW) and 12 IUGR male piglets were obtained and weaned at 21 d. NBW-weaned piglets fed basal diets (NBW group), IUGR-weaned piglets allocated to two groups fed basal diets (IUGR group) and basal diets further supplemented 600 mg Zn/kg from Nano-ZnO (IUGR+Zn group), respectively. All pigs were slaughtered at 163 d. Results showed: (1) IUGR pigs showed no difference in
body weight at 77d and 163d (P > 0.05), while had increased villus height (VH) and villus surface area in jejunum (P < 0.05) and enhanced
interleukin-6, TNF-α and NF-κB
mRNA expression (P < 0.05) as compared to NBW group; Compared with IUGR group, dietary Nano-ZnO did not affect the
body weight (P > 0.05), but increased VH to crypt depth ratio and
IgA concentration (P < 0.05) and decreased TNF-α and NF-κB
mRNA expression in jejunum (P < 0.05). (2) IUGR increased the number of swollen mitochondria and autolysosomes, and
protein expressions of sequestosome-1 (P62) and
microtubule-associated protein light chain 3 B/A (LC3B/A) in jejunum as compared to NBW group (P < 0.05); Compared with IUGR group, Nano-ZnO decreased the number of swollen mitochondria and autolysosomes, and P62 and LC3B/A
protein expression (P < 0.05). (3) IUGR increased mucosal contents of
malondialdehyde and
protein carbonyl (PC) and
Keap1 protein expression (P < 0.05) as compared to NBW group; Compared with IUGR group, dietary Nano-ZnO increased activities of total
antioxidant capacity,
catalase,
glutathione peroxidase, and
glutathione content (P < 0.05), and enhanced
nuclear respiratory factor 2 (Nrf2),
glutamate-cysteine ligase modifier subunit and
glutathione peroxidase 1 mRNA expression, and increased total and nuclear Nrf2
protein expression (P < 0.05), and decreased
malondialdehyde and PC content, and
Keap1 protein expression (P < 0.05) in jejunum. Results suggested that IUGR pigs showed postnatal catch-up growth and improved intestinal morphology, and dietary Nano-ZnO may further improve intestinal morphology, reduce
inflammation, decrease autophagy and alleviate oxidative stress via Nrf2/Keap1 pathway in jejunum of IUGR pigs.