Performance and physiological responses of E. coli-challenged broiler chickens to dietary Moringa oleifera

This study was conducted to examine the effects of Moringa oleifera (MO) seed powder on the performance and gut health of broilers challenged with E. coli. A total of 720 one-day-old Ross 308 broiler chicks were randomly allocated to 72 pens across two separate rooms, following a 2 × 6 factorial design. The factors per room included (i) challenge: no or yes, and (ii) feed additive: control (none), antibiotic [oxytetracycline (OTC) at 0.5 g/kg], MO 0.1%, MO 0.2%, MO 0.4%, and MO 0.8%. At 9 days old, birds in both challenged and non-challenged rooms were inoculated with 1.5 ml of E. coli-O157:H7 inoculant (3.8 × 108 CFU) and 1.5 ml of saline, respectively. Performance data showed that, throughout the study, unchallenged birds had better weight gain (WG) and feed conversion ratio (FCR) than challenged birds. On day 35, broilers given OTC and all MO levels showed improved WG (P < 0.001) and FCR (P < 0.003). Interactions between challenge and additives were observed on day 10 for FCR (P = 0.031); on days 24 and 35 for WG (P < 0.001); and on days 24 and 35 for FCR (P < 0.004 and P = 0.002, respectively). On day 24, challenged birds fed all MO levels exhibited higher WG and better FCR than challenged controls, while on day 35, both challenged and unchallenged MO-fed birds showed improved WG and FCR compared to control groups. E. coli significantly increased crypt depth (CD), jejunum muscle thickness, and caecal E. coli colonies. MO significantly enhanced villus height (VH), the VH : CD ratio, villous tip width, and surface area, while decreasing CD, muscle thickness, and E. coli colonies. Challenged birds had significantly lower serum total protein, albumin, and Newcastle Disease Virus (NDV) titres, while serum alanine aminotransferase ALT activity was higher than in non-challenged birds. Overall, Moringa at 0.4% showed comparable or better results than OTC in preventing E. coli-induced declines in broiler performance and gut health.