| α-Glyceryl monolaurate is a kind of medium chain fatty acid ester.In this study,the effects of GML on growth performance and immune function of weaned piglets were investigated,andthe mechanism GML on Porcine reproductive and respiratory syndrome virus(PRRSV)in vitro was investigated.This study is divided into three experiments.Experiment 1: The inhibitory effect of GML on Escherichia coli,Salmonella and Staphylococcus aureus in vitro was studied by Oxford cup method.The results showed the minimum inhibitory concentration of GML on Salmonella and Staphylococcus aureus were 0.156 mg/mL and 0.079 mg/mL,respectively.1 mg/mL GML could significantly inhibit Salmonella after 12 h treatment,and Staphylococcus aureus could be significantly inhibited after 4 h treatment.Experiment 2: The effects of GML on growth performance,immune function,flora and PRRSV antibody level of weaned piglets were studied.A total of 270 weaned piglets were divided into three groups.Piglets were fed with basic diet,basic diet + 500mg/kg GML and basic diet + 1 000mg/kg GML respectively.Serum and fecal samples were taken on the 7th,14 th and 21 st days for 21 days,to detection of serum immune factors,PRRSV antibody levels and the number of Escherichia coli,Salmonella and Lactobacillus in fecal samples.The results showed that feeding GML improved the growth performance of piglets.The number of fecal Escherichia coli and Salmonella in GML piglets were significantly lower than that in control piglets.The inflammatory factors TNF-α,IL-6 and IL-1β in serum were significantly decreased,and the level of PRRSV antibody in serum was decreased compared with the control piglets.Feeding with 1 000mg/kg GML was better than 500mg/kg GML.Experiment 3: The effect of GML pretreatment on the prevention of PRRSV infection in MARC-145 cells and the effect of GML treatment on PRRSV infected MARC-145 cells were studied.The results showed that GML reduced the gene expression of PRRSV-N protein in MARC-145 cells,reduce the expression of inflammatory factor IL-6.In conclusion.The GML inhibits Salmonella and Staphylococcus aureus in vitro.The GML regulated intestinal flora of weaned piglets,reduced the number of E.coli and Salmonella in feces.The GML reduced the levels of inflammatory factors and virus antibodies in serum of piglets.The GML inhibited the infection of PRRSV on MARC-145 cells and decreased the gene expression of IL-6. |
