The aim of this study was to evaluate the efficacy of a microencapsulated blend of botanicals (BOT, AviPower®5) in diets for newly weaned pigs orally challenged with F18+ enterotoxigenic E. coli (ETEC).
Sixty-four 21-day-old weaning pigs were divided in 4 groups (n=16): negative control (NC, basal diet); positive control (PC, basal diet); treated groups with BOT added in basal diet (BOT1: 1 kg/MT; BOT2: 2 kg/MT). On d7, PC, BOT1, and BOT2 were challenged with ETEC (1.5×1010 CFU). Growth performance and fecal score were recorded until d28. On d14, half of pigs were euthanized to collect jejunal samples for mucosa-associated microbiota and intestinal health analysis. Data were analyzed with SAS MIXED procedure.
During d7 to 14, PC had lower (p < 0.05) growth performance compared to NC. During d7 to 28, G:F was improved (p < 0.05) in BOT1 and BOT2 compared to NC and PC. From d7 to d11, fecal score was worsened (p < 0.05) in PC compared to NC but, on d10, BOT improved (p < 0.05) it compared to PC.
Despite the challenge, the mucosa-associated microbiota of PC was not different from NC, but BOT1 and BOT2 showed lower (p < 0.05) Staphylococcus compared to NC and PC. However, PC had reduced (p < 0.05) ZO-1 and occludin in the jejunum compared to NC, whereas BOT1 and BOT2 increased (p < 0.05) their expression and tended to reduce TLR4 levels compared to NC and PC. The jejunal mucosa of PC also had higher (p < 0.05) IL-6, but BOT1 and BOT2 reduced its concentration to the same of NC. Moreover, intestinal Ki-67+ was reduced (p < 0.05) in PC, but it was increased (p < 0.05) in BOT1 and BOT2 compared to PC.
In conclusion, BOT could improve growth performance and fecal scores of newly weaned pigs by supporting their health during ETEC challenge through the modulation of mucosa-associated microbiota, reduction of inflammatory response, and enhancement of gut integrity in the jejunum.
