Dietary inclusion of multispecies probiotics to reduce the severity of post-weaning diarrhea caused by Escherichia coli F18+ in pigs

This study was aimed to determine the efficacy of multispecies probiotics in reducing the severity of post-weaning diarrhea caused by enterotoxigenic Escherichia coli(ETEC)F18+on newly weaned pigs.Thirty-two pigs(16 barrows and 16 gilts,BW=6.99±0.33 kg)at 21 d of age were individually allotted in a randomized complete block design with 2×2 factorial arrangement of treatments.Pigs were selected from sows not infected previously and not vaccinated against ETEC.Pigs were fed experimental diets for 25 d based on 10 d phase 1 and 15 d phase 2.The factors were ETEC challenge(oral inoculation of saline solution or E.coli F18+at 2×109 CFU)and probiotics(none or multispecies probiotics 0.15%and 0.10%for phase 1 and 2,respectively).Body weight and feed intake were measured on d 5,9,13,19,and 25.Fecal scores were measured daily.Blood samples were taken on d 19 and 24.On d 25,all pigs were euthanized to obtain samples of digesta,intestinal tissues,and spleen.The tumor necrosis factor alpha(TNFα),malondialdehyde(MDA),peptide YY(PYY),and neuropeptide Y(NPY)were measured in serum and intestinal tissue.Data were analyzed using the MIXED procedure of SAS.The fecal score of pigs was increased(P<0.05)by ETEC challenge at the post-challenge period.The ETEC challenge decreased(P<0.05)jejunal villus height and crypt depth,tended to increase(P=0.056)jejunal TNFα,increased(P<0.05)ileal crypt depth,and decreased(P<0.05)serum NPY.The probiotics decreased(P<0.05)serum TNFα,tended to reduce(P=0.064)jejunal MDA,tended to increase(P=0.092)serum PYY,and increased(P<0.05)jejunal villus height,and especially villus height-to-crypt depth ratio in challenged pigs.Growth performance of pigs were not affected by ETEC challenge,whereas the probiotics increased(P<0.05)ADG and ADFI and tended to increase(P-0.069)G:F ratio.In conclusion,ETEC F18+challenge caused diarrhea,intestinal inflammation and morphological damages without affecting the growth performance.The multispecies probiotics enhanced growth performance by reducing intestinal inflammation,oxidative stress,morphological damages.