Comparison of Garlic (Allium sativum), Probiotic and Antibiotic Supplementation as Growth Promoters in Broiler Chickens

Abstract

Unconventional feed additives such as herbs, medicinal and aromatic plants, organic acids, and probiotics have been used as alternatives to antibiotics to enhance growth in poultry and farm animals. This study aimed to evaluate the effects of garlic and probiotics on growth promotion compared to antibiotics. A total of 240 unsexed one-day-old broiler chicks (Ross 308 strain) were used. At two weeks of age, the chicks were randomly assigned to four experimental groups: a control group fed a basal diet, a second group fed a diet containing 0.5% garlic, a third group fed a diet containing 0.5% probiotic (yeast), and a fourth group fed a diet supplemented with 50 ppm of the antibiotic enrofloxacin. The evaluated parameters included feed intake, feed conversion ratio, final body weight, body weight gain, absolute and relative carcass weight, breast, and thigh, and the amount of blood loss. Additionally, the weight and length of selected internal organs were measured. Overall, the results indicated that the productive performance traits, carcass weight and its components, and internal organ measurements of birds fed diets containing garlic, probiotics, or antibiotics showed no significant differences (p≥0.05) compared to the control group. Exceptions included the superiority of the control group over the other groups in terms of the absolute weight of the carcass and its cuts, also a significant decrease in weight gain in the garlic group (1728.15 g vs 1873 g in the control group), a reduction in feed intake in the probiotic group (2695.33 g vs 2725.33 g in the control group), and decreased liver weight and increased spleen weight in the antibiotic group (35.51 g and 3.93 g). It is concluded that under the conditions of this study, the inclusion of garlic, probiotics, or antibiotics at the tested levels did not exert a growth-promoting effect in broiler chickens.