Effect Of PGRF Gene Plasmid On Weaned Piglets Which Immune-challenged By LPS Or Triple Vaccine

The purpose of this study was to evaluate the effect of pGRF gene plasmid on the performance and immunological function of immune-challenged Weaned Piglets for28±2d by LPS and triple vaccine,and also the potential mechanism of these effects were discussed.Thirty-six weaned DLY pigs with age of 28±2d and initial were paired assigned to six treatments according to gender and weight by single factor design.Each treatment had six replicates,three male and three female,each replicate has one piglet.The six treatments were contronl group;1.0 mg pGRF gene plasmid group;100μg/kg.BWLPS (lipopolysaccharide)group;1.0 mg pGRF+100μg/kg BWLPS group;double dose Triple vaccine group and pGRF+double dose Triple vaccine group.In the beginning of the experiment,pGRF gene plasmid group,pGRF+LPS group and pGRF+triple vaccine group were only once injected 1.0mg pGRF gene plasmid per head and only one time,.At 11 and 18 day of the experiment,pGRF+LPS group and LPS(lipopolysaccharide)group were injected lipopolysaccharide according to 100μg per kilogram body weight;pGRF+ triple vaccine group and triple vaccine group were injected double dose triple vaccine; pGRF gene plasmid group and control were injected normal saline.Three hour after injected the peripheral blood were get and serum were dieresised,the concentration of IGF-I,IL-1,IgG and IL-6 in serum were measured.Feed consumption,average daily gain (ADG),feed to gain ratio(F/G)were recorded.Dietary treatment did not have additive antibiotics.During the 25 days experiment the piglets were allowed ad libitum to feed and water,the the concentration of IgG were determined using immuno-turbidimetry method, and IGF-I,IL-1 and IL-6 was determined by ELISA technique.The results were as follows: 1)The piglets in the pGRFand pGRF+LPS groups had a better growth performance than those in the LPS group(P＜0.05),The piglets in the pGRFand pGRF+Triple vaccine group had a better growth performance than those in the Triple vaccine group group(P＜0.05).2)The concentration of serum IGF-1 in the pGRF group was significantly higher(P＜0.01)than both in the pGRF+LPS and LPS groups,and also between the latter two groups there were significant difference in IGF-1(P＜0.05).It has the same rule in the groups that deal whitTriple vaccine.3)The concentration of serum IgG in the pGRF and pGRF+LPS groups was higher(P＜0.05)than that in the LPS group,The concentration of serum IL-1 and IL-6 in the pGRFand pGRF+LPS groups was significantly higher(P＜0.01)than those in the LPS group.It has the same rule in the groups that injected Triple vaccine.So,it can be said that:pGRF can improve statuses of immune challenge induced by lipopolysaccharide injection and Triple vaccine,and improve the growth performance and Immunological function of the weaned piglets.