There are concerns about inclusion of antibiotics in the feed of broiler chickens, because of the development of antibiotic resistance, leading to a search for alternative feed additives. Turnip extract is known to have antibacterial properties but has not been tested in the diet of broiler chickens. We allocated 200 broiler chicks to receive one of four levels of turnip extract in their water, 0, 150, 300 or 450 ppm, or a standard antibiotic, Virginiamycin, over a 42-day growing period. Although initially there were detrimental effects of providing 450 ppm, overall the 150 ppm level of supplementation increased weight gain, compared with birds given Virginiamycin, and decreased gizzard weight. Birds given 150 ppm or Virginiamycin had increased low-density lipoproteins (LDLs) and reduced very low-density lipoproteins (VLDLs) in their blood serum and reduced antibody responses to sheep red blood cells, compared to birds in the 450 ppm treatment. Birds given turnip extract at 450 ppm had fewer Gram-negative lactose and coliform bacteria than those provided with no turnip extract, and those provided with 150–300 ppm had the same as those provided with Virginiamycin. Turnip extract could potentially replace antibiotics included in the feed of broiler chickens for growth promotion and the control of bacterial infection of the gastrointestinal tract.
Antibacterial Properties of Whey Protein Coating and Mentha aquatica L. Essential Oil on Coliform Bacteria in Iranian White Cheese
