The present study was designed to find the effect of an antibiotic, an organic acid and a probiotic on performance traits, blood biochemical parameters and antioxidant status during the starter phase exposed to Salmonella typhimurium challenge. A total of 300 day-old broiler chicks were randomly allocated to control (basal diet), T1: infected with Salmonella enteric subsp. Typhimurium; T2: infected + avilamycin; T3: infected + organic acid; T4: infected + Bacillus subtilis; T5: infected + organic acid + probiotic. The results showed that body weight, feed conversion ratio and production efficiency factor did not differ (P > .05) between the control and treated groups. Blood albumin and aspartate aminotransferase increased significantly (P < .05) in birds in T5 during the first week. Similarly, total protein and triglyceride concentration increased significantly (P < .05) in T4 and T5. The total antioxidant capacity in the second week decreased significantly in T4 compared to the control. Thiobarbituric acid reactive substances during the first and second weeks did not differ significantly (P > .05) between the control and treated groups. We concluded that the effect of organic acid blend and B. subtilis was similar to that of the antibiotic in broilers during the starter phase exposed to S. typhimurium challenge.

A total 560 day-old broiler chicks (Ross 308) was randomly allocated to seven treatments (eight replicates). Control (basal diet), T1, infected with Clostridium perfringens, T2, infected + Avilamycin at the rate of 0.2 g/kg T3, infected + essential oil of thyme, T4, infected + Sanguinarine, T5, infected + Anti-Salmonella phytobiotic, T6., infected + essential oils of thyme, anise and others (oregano, carvacol, yucca extract and cinnamaldehyde). Feed conversion ratio (FCR) were significantly (P<0.05) high in the T2 during the third week. The dressing percentage decreased significantly (P<0.05) and intestinal weight increased (P<0.05) in T1. Blood protein, and globulin increased significantly (P<0.05) in birds in T6 during fourth weeks, while blood alanine transaminase (ALT) increased significantly (P<0.05) in T5. Thiobarbituric acid reactive substances (TBARS) increased significantly (P<0.05) in T5 and T6. Similarly, villus height and width increased significantly (P<0.05) in T5 and T6. From the results of the present study, it was concluded that different feed additives could be substituted with antibiotics in the feed of broiler exposed to Clostridium perfringens challenge.

There is a growing concern over the use of antibiotics due to the increased resistance of pathogens in broiler. The present study was designed to find the comparative effect of an antibiotic, and some phytogenic on performance traits, blood biochemical parameters, and antioxidant status during starter phase exposed to Salmonella typhimurium challenge. A total of 560-day-old broiler chicks (Ross 308) were randomly allocated to seven treatments (eight replicates). Control (basal diet); T1, infected with Salmonella enterica subsp. typhimurium; T2, infected + avilamycin at the rate of 0.2 g/kg; T3, infected + essential oil of thymol; T4, infected + phytogenic; T5, infected + anti-Salmonella organic acid; and T6, infected + essential oils of thyme, anise, and other components. Body weight gain and feed conversion ratio (FCR) were significantly (P < 0.05) high in the T2 and T5 at the end of the first and the second week and similar to T4. During the second week, European production efficiency factor (EPEF) was also significantly (P < 0.05) high in T2, T4 and T5. Blood albumin increased significantly (P < 0.05) in birds of T2 in the first week, while during the second week, blood glucose and triglyceride concentration decreased significantly (P < 0.05) in T5. Blood ALT concentration decreased significantly (P < 0.05) in T6 compared to other treatments in the second week. Total antioxidant capacity (at the end of the second week) and thiobarbituric acid reactive substances (TBARS) did not change significantly. From the results of the present study, it was concluded that different feed additives could be substituted with antibiotics in the feed of broiler exposed to S. typhimurium challenge.