Effects of acetic acid supplementation in broiler chickens orally challenged with Salmonella pullorum

This study was conducted to investigate the comparative efficacy of three different concentrations of acetic acid on broiler chickens experimentally challenged with Salmonella enterica serovar Pullorum (S. Pullorum). A total of 360 birds were divided into five groups (A–E). Group A served as the unchallenged, untreated control. All the birds in groups B–E were challenged with 4 × 104 cfu/mL of S. Pullorum. Birds in groups C, D, and E were respectively treated with three different concentrations, 0.5%, 1%, and 1.5%, of acetic acid. Pathological examination revealed congested and hemorrhagic liver, hepatitis and necrotic areas in the liver, hydropericardium, focal necrosis in the spleen, epithelial desquamation of the intestinal mucosa, and congested lungs and hazy appearance of air sacs in birds challenged with S. Pullorum. Acetic acid supplementation (1%) helped to reduce the number and severity of these gross and histopathological changes. Counts of S. Pullorum in cecal digesta were significantly reduced with increasing concentrations of acetic acid (P < 0.05). However, acetic acid supplementation at a higher rate (1.5%) also showed adverse effects in terms of higher percentage of diarrhea and bad growth performance in birds challenged with S. Pullorum. Among the three different concentrations, 1% acetic acid supplementation showed partially protective effects by showing better growth performance, lower feed conversion ratios (P < 0.05), and lower rates of gross and histopathological changes.