The aim of the study was to evaluate a botanical-based feed additive (BOT) both in vitro on cultured enterocytes and in vivo in weaner piglets orally challenged with F4+ enterotoxigenic E. coli (ETEC).
In vitro, Caco-2 cells were treated with BOT and infected with 5×107 CFU of ETEC (BOT+); enterocytes integrity, and ETEC adhesion and translocation were measured. Unchallenged (CTR-), challenged (CTR+), and antibiotic (colistin, COL+) controls were included.
In vivo, 30 F4-susceptible weaner pigs were divided in 3 groups (n=10): positive control (CTR+, no treatments); control with colistin in water (COL+); treatment receiving BOT, microencapsulated in lipid matrix, at 2 kg/MT (BOT+). On d9, each pig was orally challenged with 3×109 CFU of ETEC. Body weight (BW), fecal score, and ETEC shedding were recorded until d23.
Data were analyzed with ANOVA (in vitro) or ANCOVA (in vivo, covariate: d0 BW), with differences significant at P<0.05 and tendencies at P≤0.1.
In vitro, integrity of CTR+ enterocytes was significantly reduced (26% of starting value), while BOT+ kept it at around 80%, in line with CTR- and COL+. Moreover, BOT+ reduced ETEC adhesion and translocation across enterocytes by 1 log10(CFU/mL) (p<0.05).
In vivo, despite BOT+ led to higher overall fecal ETEC shedding vs CTR+ and COL+ (P<0.001), no differences were observed in fecal scores, and BOT+ tended to improve BW compared to both CTR+ and COL+ at d14 (+1.1 kg) and d23 (+1.5 kg).
BOT protected enterocytes during ETEC infection in vitro and may support growth of ETEC-challenged piglets.
Section: 35 – Advances in non ruminant nutrition
Presentation: Theater (oral)
Presenting: Andrea Bonetti
Keywords: Feed supplements and additives, Adaptation and stress, Health, Production diseases, Multifactorial diseases, Growth and development
Species (mainly) related: Pigs
Discipline (mainly) related: Nutrition
