Antibacterial Effect Of Lysozyme Preparation And Its Application In The Diet Of Weaned Piglet

In this study,lysozyme was used to replace antibiotics in diets of nursery piglets.The feeding experiments were carried out to study the feasibility and mechanism of lysozyme to replace antibiotics in diets of weaned piglets via evaluating the growth performance,blood biochemical indexes and intestinal mucosal morphology.A total of 180 piglets were randomly assigned to five different diets(control group,antibiotic group,50 mg/kg lysozyme group A,100 mg/kg lysozyme group B,200 mg/kg lysozyme group C according to the principle of similar weight,same source and half of male and female.There were six replicates with six piglets per replicate per dietary treatment.Piglets were weaned at 23 days of age and entered the experiment.The feeding experiment lasted for 2 weeks.The results are as follows:(1)Lysozyme exhibited bacteriostatic activity against three pathogenic bacteria(Staphylococcus aureus,Escherichia coli and Salmonella)at concentrations of 50,100 and 200 ug/m L.There was no significant difference in average daily feed intake and daily gain among the antibiotic group and the lysozyme group.(2)Dietary lysozyme supplementation of 50 mg/kg or 100 mg/kg could maintain the similar average daily feed intake and daily gain at the same level as that of antibiotic supplementation group,but using 200 mg/kg lysozyme replacing colistin sulfate could reduce the average daily feed intake and daily gain of piglets,but the reduction was not significant.(3)The height of jejunal villus was greatly affected by the amount of lysozyme added,which shows the change rule of first increasing and then decreasing with the increase of lysozyme.The amount of lysozyme added has no significant effect on the height of ileal villus.In conclusion,lysozyme exhibited bacteriostatic activity against Staphylococcus aureus,Escherichia coli and Salmonella,50 or 100 mg/kg lysozyme supplementation in the diet of weaned piglets can obtain the similar growth performance as antibiotics group.Adding 100 mg/kg lysozyme can effectively reduce diarrhea in piglets.