EFFECT OF ANTIBIOTIC ALTERNATIVES IN POULTRY NUTRITION: PHYTOCHEMICALS AND PROBIOTICS

Abstract

This study assessed the impact of dietary phytochemicals and probiotics, both separately and in combination, as substitutes for antibiotic growth boosters in broiler chickens conducted at University of Veterinary and Animal Sciences, Lahore. A total of 480-day-old Ross 308 chicks were assigned to four dietary treatments in a 2 × 2 factorial design: control (base diet), phytochemical supplementation (500 mg/kg essential oil mix), probiotic supplementation (1 g/kg multi strain preparation), and a combination of both interventions. Growth performance, intestinal morphology, cecal microbiota, immunological responses, and oxidative stress indicators were assessed throughout the 42-day study. The results indicated that both phytochemicals and probiotics enhanced body weight and feed conversion ratio relative to the control group (P < 0.05), with the most significant benefit noted in the combination group (BWG = 2,625 g; FCR = 1.61). Birds administered supplements showed increased villus height and villus-to-crypt ratio, decreased Escherichia coli counts, and elevated populations of Lactobacillus spp. Immunological studies demonstrated increased serum IgA and IgG levels and diminished pro-inflammatory cytokines (IL-6 and TNF-α) in the supplemented groups; however, oxidative stress markers showed decreased malondialdehyde levels and increased antioxidant enzyme activity. The combined use of phytochemicals and probiotics consistently yielded the best results in terms of performance, gut health, immunological function, and oxidative metrics, indicating a synergistic effect. These findings indicate that phytochemicals and probiotics serve as viable, sustainable alternatives to antibiotics in poultry production, enhancing productivity and animal health, while diminishing dependence on antimicrobial growth boosters.