Effects of Lacticaseibacillus paracasei and Monensin on Performance and Antioxidant Status in Eimeria tenella Infected Broilers

Coccidiosis caused by Eimeria tenella remains one of the most detrimental parasitic diseases in poultry, leading to impaired growth performance, poor feed conversion, and substantial economic losses, thereby hindering sustainable poultry production.This study aimed to evaluate the effects of the probiotic Lacticaseibacillus paracasei, administered alone or in combination with the anticoccidial agent monensin, on growth performance, feed conversion ratio (FCR), and antioxidant status in broiler chickens experimentally infected with E. tenella.A total of 125 one-dayold broiler chickens were randomly assigned to five groups: uninfected control, infected control, monensin, probiotic, and combined probiotic plus monensin.The probiotic was provided in drinking water (4 mL/L; 1 × 10⁸ CFU/mL), while monensin was included in the diet (1 g/kg).Growth performance parameters and antioxidant indicators, including superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels, were measured and statistically analyzed.The co-administration of L. paracasei and monensin significantly (P < 0.05) increased body weight gain and improved FCR compared to the infected control group.Furthermore, these enhancements were statistically superior (P < 0.05) to those observed with probiotic treatment, indicating a synergistic effect of combined treatment.These findings suggest that supplementation with L. paracasei, particularly when combined with monensin, enhances feed efficiency, oxidative balance, and overall health performance in E. tenella infected broilers.The integration of probiotics with anticoccidial agents represents a promising strategy for sustainable poultry production and improved food security.