Effects of organic acid supplementation on antioxidant capacity and immune responses of broilers challenged orally with Salmonella enterica subsp. enterica Typhimurium

Four commercial organic acids and a reference antibiotic, Neoxyval, were administered to commercial broilers to evaluate the efficacy of these products during pre- and post-challenge with Salmonella enterica subsp. enterica Typhimurium (S. Typhimurium) on selected indicators of their antioxidant status and immune responses in serum. Two hundred and eight broilers received one of the following seven treatments: positive control group (CTL+); negative control (CTL.); antibiotic Neoxyval, (NEOX); Gallimix (GALI); FormaXOL (FORMA); Fysal (FYS); and Selko-pH in drinking water (SELK). The chicks in treatments T2 to T7 were challenged with (3 x109 cfu/mL) of S. Typhimurium on day 16. Each treatment consisted of 10 cage replicates with four birds per cage for a starter (0 - 14 days of age) and a finisher (15 - 42 days of age) period. The results revealed that the total antioxidant capacity (TAC) value was highest when birds were supplemented with organic acids, with the highest value for FORMA (0.70 mM), which was not different from those of the FYS (0.67 mM), SELK (0.66 mM) and GALI (0.64 mM) treatments. Birds receiving treatment, CTL., produced the highest H2O2 value (75.9 ìM), while, FYS, FORMA and SELK lowered H2O2 concentration significantly (51.1, 53.8 and 55.0 ìM, respectively). Anti-Salmonella titre was significantly improved by dietary organic acid supplementation. The highest Salmonella titre was recorded for birds that received FORMA (1.54) as compared with all other treatments. Week of sampling showed a significant effect on Salmonella and Newcastle disease titres. In summary, the tested organic acids, especially FORMA, had a positive influence on TAC and Salmonella titres and reduced the H2O2 concentration in serum.Keywords: Broilers, immune responses, organic acids, oxidative stress, total antioxidant capacit