Antibacterial effects of nano-emulsified cumin oil on performance and carcass characteristics in weaning rabbits infected by Clostridium perfringens type A

Abstract

Background

This study aimed to evaluate the antibacterial effects and growth-promoting potential of nano-emulsified cumin oil (NECO) in vitro and in vivo trials using newly weaned Gabaly rabbits. NECO was tested as both a preventive and curative agent against Clostridium perfringens type A infection through dietary supplementation.

Methods

The study included two experimental phases: (1) an in vitro trial to determine the bacterial inhibition potential of different NECO concentrations (0.1, 0.2, 0.5, and 1 mL) and (2) an in vivo trial using 120 four-week-old newly weaned male Gabaly rabbits (0.544 kg average body weight) allocated into five groups (n = 24/group were divided into 3 replicates, 8 animals each). The groups were: G1 (negative control, no infection or supplement), G2 (NECO control, supplemented with 10 mL/kg diet), G3 (positive control, infected with C. perfringens type A, no supplement), G4 (preventive NECO, supplemented with 10 mL/kg diet before infection), and G5 (curative NECO, supplemented with 10 mL/kg diet after infection). NECO was formulated as a stable nano-emulsion using a high-shear homogenizer.

Results

The in vitro study demonstrated that NECO inhibited C. perfringens growth at all tested concentrations, with complete inhibition observed at 1 mL. Based on this, the 1 mL concentration was selected for in vivo trials. Infected rabbits (G3) exhibited clinical signs including anorexia, depression, severe diarrhea, and bloat, with a morbidity rate of 90% and a 35% mortality rate by the 5th day post-challenge. NECO supplementation significantly improved (p < 0.05) final body weight (FBW), total weight gain, and average daily gain (ADG) in G2 compared to G3. While G4 and G5 did not significantly differ in FBW or ADG from the control (G1), all NECO-supplemented groups had improved feed conversion ratio (FCR) compared to G3 (p < 0.05). The best FCR was observed in G2 (3.80), followed by G4 (4.51) and G5 (4.77), while the worst was in G3 (5.31). Histopathological and postmortem findings confirmed reduced disease severity with NECO supplementation.

Conclusion

These results suggest that NECO serves as a natural antibacterial alternative, effectively mitigating C. perfringens infection while enhancing growth performance.