Injection of pGRF Gene Plasmid May Relieve Growth Depression Induced by Lipopolysaccharide in Weanling Piglets

The purpose of this study was to evaluate the effect and the potential mechanism of administering a pGRF gene plasmid on the growth and immunological function of weanling piglets subjected to immune-stress.Eighteen weanling(Duroc×Landrace×Large White) piglets aged 35 d±2 d and initial BW of 7.86 kg±0.59 kg were randomly assigned to three treatments according to gender and BW by using a single factor design.The three treatments were injections of a pGRF gene plasmid,pGRF gene plasmid followed by challenge with lipopolysaccharide(LPS),and LPS to piglets not receiving the plasmid.Each treatment group consisted of six piglets.The results were as follows:piglets in the pGRF gene plasmid plus LPS treatment had a better growth performance than those only receiving LPS(P0.05), and F/G of piglets in the pGRF gene plasmid plus LPS group were very slightly lower(P0.05) than those in the LPS group;serum levels of IGF-1 in the pGRF gene plasmid plus LPS group were significantly higher than those in the LPS group(P0.05 or P0.01);serum levels of IgG in the pGRF gene plasmid plus LPS group were higher than those in the LPS group(P0.05);serum levels of IL-1 and IL-6 in the pGRF gene plasmid plus LPS group were significantly lower than those in the LPS group(P0.05 or P0.01).