Real-time PCR detection of the effect of postweaning on the expression of cytokines and NF-kB in piglets.

: Pig weaning involves radical changes, which affect health, behavior and performance. Weaning stress dramatically impacts the porcine immune system. This study aimed to evaluate the expression of different cytokines and nuclear factor kappa B (NF-kB) in growing postweaning pigs. Forty piglets weaned at 28 days of age, with an average starting weight of 10.12±0.28 kg were considered for the analysis (time 0) and followed up for 28 days (time 1). Growth performance, skin lesions, cytokines and NF-kB expression were measured. The results showed an increased expression of two cytokines with pro-inflammatory effect, interleukin (IL)-8 and interferon-gamma (IFN-γ), a cytokine with anti-inflammatory effect, IL-4, and a cytokine with both pro- and anti-inflammatory effects, IL-6. An effect of time was observed for body lesions. Compared to females, male piglets had higher levels of all cytokines tested (IL-1β, IL-6, IL-8, IL-10, TNF-α, IL-4) except IFN-γ. Also NF-kB resulted expressed higher in males compared to females. In conclusion, this study demonstrated that weaning in piglets is associated with increased expression of inflammatory cytokines.