Autophage targeting bile-resistant Enterococcus sp. as a lipid digestibility and emulsification modifier and...

The ban on antibiotic growth promoters has intensified the demand for precise alternatives to sustain growth and gut health in poultry. The present study aimed to evaluate the impact of isolated autophages against Enterococcus bacteria resistant to high concentrations of bile on lipid digestion and chicken performance. A total of 240 one-day-old Arian × Hy-Line W36 chicks were assigned to five equal groups replicated six times with eight chicks per cage in a completely randomized design. Data were subjected to one-way ANOVA, and differences among treatments were considered significant at P < 0.05. The treatments included a control group, phage group (receiving an oral phage dose of 108 PFU) per day, Enterococcus group (receiving an oral Enterococcus dose of 106 CFU), ox bile (0.4 g/kg), and virginiamycin antibiotics (0.2 g/kg). Results showed that phage against Enterococcus sp. improved the feed conversion ratio (FCR) like virginiamycin (2.87 and 2.84, respectively) with a significant difference from other treatments (P < 0.05). Ether extract digestibility (81.48% vs. 79.27%) and in vitro oil-emulsification index (13.0% vs. 4.2%) were significantly increased in the phage-treated group compared with the control (P < 0.05), indicating improved lipid utilization. Phage against Enterococcus sp. increased intestinal gram-negative bacteria counted on MacConkey agar compared with other groups (P < 0.05). In vitro oil-emulsification index perfectly mirrored the inhibition of bile salt hydrolase (BSH) activity in ileum digesta of antibiotics and bacteriophage-treated groups. It could be concluded that specific inhibition of Enterococcus bacteria with high bile hydrolase activity by bacteriophage can improve EE digestibility and performance like growth-stimulating antibiotics.