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(P【0.05), and F/G of piglets in the pGRF gene plasmid plus LPS group were very slightly lower(P】0.05) 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(P【0.05 or P【0.01);serum levels of IgG in the pGRF gene plasmid plus LPS group were higher than those in the LPS group(P【0.05);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(P【0.05 or P【0.01).

Dietary ellagic acid supplementation attenuates intestinal damage and oxidative stress by regulating gut microbiota in weanling piglets

Intestinal oxidative stress triggers gut microbiota dysbiosis,which is involved in the etiology of postweaning diarrhea and enteric infections.Ellagic acid(EA)can potentially serve as an antioxidant supplement to facilitate weaning transition by improving intestinal oxidative stress and gut microbiota dysbiosis.Therefore,we aimed to investigate the effects of dietary EA supplementation on the attenuation of intestinal damage,oxidative stress,and dysbiosis of gut microbiota in weanling piglets.A total of126 piglets were randomly assigned into 3 groups and treated with a basal diet and 2 m L saline orally(Ctrl group),or the basal diet supplemented with 0.1%EA and 2 m L saline orally(EA group),or the basal diet and 2 m L fecal microbiota suspension from the EA group orally(FEA group),respectively,for 14 d.Compared with the Ctrl group,EA group improved growth performance by increasing average daily feed intake and average daily weight gain(P<0.05)and decreasing fecal scores(P<0.05).EA group also alleviated intestinal damage by increasing the tight junction protein occludin(P<0.05),villus height,and villus height-to-crypt depth ratio(P<0.05),while decreasing intestinal epithelial apoptosis(P<0.05).Additionally,EA group enhanced the jejunum antioxidant capacity by increasing the total antioxidant capacity(P<0.01),catalase(P<0.05),and glutathione/oxidized glutathione(P<0.05),but decreased the oxidative metabolite malondialdehyde(P<0.05)compared to the Ctrl group.Compared with the Ctrl group,EA and FEA groups increased alpha diversity(P<0.05),enriched beneficial bacteria(Ruminococcaceae and Clostridium ramosum),and increased metabolites short-chain fatty acids(P<0.05).Correspondingly,FEA group gained effects comparable to those of EA group on growth performance,intestinal damage,and intestinal antioxidant capacity.In addition,the relative abundance of bacteria shifted in EA and FEA groups was significantly related to the examined indices(P<0.05).Overall,dietary EA supplementation could improve growth performance and attenuate intestinal damage and oxidative stress by regulating the gut microbiota in weanling piglets.