Enhancing Broiler Growth, Carcass Quality, Blood Parameters and Intestinal Microbial Load: The Role of Dietary Garlic Powder as a Natural Growth Promoter

Abstract This study evaluated the effects of garlic powder (GP) as a natural growth promoter in broiler diets, replacing traditional antibiotics. Four experimental groups of 264 day-old broiler chicks (Ross 308) were established in a fully randomized design experiment. Each group had six replicates, each with eleven unsexed chicks. The treatments were used as follows: The 1st group was the basal diet without any additive (control group). 2nd, 3rd and 4th groups (GP1, GP2 and GP3) receiving basal diet + 1, 2, and 3 g GP/kg feed, respectively. Results demonstrated that 2 and 3 g GP/kg diets significantly improved feed conversion ratio (FCR), while 1 g GP/kg feed led to the greatest gains in body weight, weight gain, and feed intake. Blood analysis revealed elevated total protein, albumin, and A/G ratios across all GP groups, alongside reduced creatinine and ALT levels. The 3 g GP/kg diet notably increased HDL and reduced total cholesterol (TC) and LDL concentrations. Immunoglobulin Y (IgY) levels were highest in birds fed 1 and 3 g GP/kg, with IgM levels peaking in the 1 g GP group. Additionally, the 3 g GP/kg diet enhanced superoxide dismutase (SOD) activity and reduced malondialdehyde (MDA) levels, a marker of oxidative stress. In contrast, the control group exhibited the highest MDA levels. Additionally, the highest lactic acid bacteria (LAB) and total bacterial count (TBC) were found in the GP1 group. However, the control group had the highest levels of E. coli. In conclusion, incorporating garlic powder into broiler diets enhanced immune response, blood parameters, overall growth, and gut bacteria counts with optimal effects observed at 1 and 3 g GP/kg.