Effects Of Coated Plant Essential Oil On Growth Performance And Intestinal Function Of Weaned Piglets As A Substitution Of Colistin Sulfate

The experiment was to study the effects of different levels of coated essential oils on growth performance,intestinal flora,inflammatory response,antioxidant activity and intestinal barrier function of weanling piglets as a substitution of colostin sulfate.Two hundred crossbred piglets weaned at 25 d with body weight of 7.23 ± 0.75 Kg were randomly divided into 5 groups,each group had 5 columns.Each column had 8 piglets with half of the male and female.Two groups with a basic diet of colostin sulfate or no colostin sulfate served as antibiotic group or control group.The other 3 groups were fed with diets basically included 100,200,300 mg/kg essential oils without colostin sulfate.Feeding research of 35 days was divided into two stages.On the 7th day after weaning,five piglets were selected for slaughter and sampling from the control group,antibiotic group and 200 mg/kg essential oils group.The results are as follows:(1)Adding 100 mg/kg or 200 mg/kg coated essential oils groups could maintain a growth performance comparable to the antibiotic group.However,adding 300 mg/kg coated plant essential oil significantly reduced the feed intake and daily gain(P <0.05).(2)Compared with the control group,adding of coated essential oils or colostin sulfate could significantly reduce the diarrhea rate of piglets(P <0.01).Adding 200 mg/kg,300 mg/kg essential oils or 60 mg/kg colostin sulfate could significantly reduce the diarrhea score(P <0.05).(3)Compared with the control group,the addition of essential oils or antibiotics could significantly reduce the quantity of Escherichia coli and Enterococcus in colon contents(P <0.05),and had no significant effect on the quantity of Lactobacillus(P> 0.05).(4)Compared with the control group,adding 200 mg/kg essential oils could significantly increase the villus height and the ratio of villus length to crypt depth(P <0.05),increased the mRNA level of occludin in jejunum mucosa of piglets(P <0.01),reduced the content of D-lactic acid and DAO activity in plasma at the 7th and 14 th day after weaning(P <0.01).(5)Compared with the control group,adding 200 mg/kg essential oils could significantly reduced the mRNA level of the intestinal inflammatory cytokines of IL-1?(P <0.01)and TNF-?(P<0.05).In addition,adding 200 mg/kg essential oils could significantly increase the concentration of sIgA in the jejunum mucosa(P< 0.05).(6)Compared with the control group,adding 200 mg/kg essential oils could significantly increase the activity of SOD and GSH-px in jejunum homogenate,and significantly decrease the content of MDA(P <0.05).On the other hand,adding essential oils could significantly decreased the content of ROS in plasma at the 7th and 14 th day after weaning(P <0.01).In conclusion,adding 100 or 200 mg/kg coated essential oils in weaning piglet diets could maintain a growth performance comparable to that of adding 60 mg/kg of colostin sulfate.The addition of coated essential oils is beneficial to reduce the number of intestinal pathogens in weaned piglets,relieve oxidative stress and inflammation state,strengthen the intestinal barrier function,eventually alleviate weaning diarrhea.