Effects of dietary alternatives (probiotic, green tea powder, and Kombucha tea) as antimicrobial growth promoters on growth, ileal nutrient digestibility, blood parameters, and immune response of broiler chickens

A feeding trial was conducted to study the effects of alternative antimicrobial growth promoters (probiotic, Kombucha tea, and green tea powder) in wet, wheat-based diets on broiler performance, carcass yield, organ weights, immune response, and histomorphological measurements of the small intestine. One hundred and sixty-one-day-old male broiler chicks were randomly assigned to 1 of 4 dietary treatments for 6 weeks. The dietary treatments were: (a) control (1.2 g water/gram of dry feed), (b) control diet supplemented with 1 g/kg probiotic (8 × 105 colony forming units (CFU) of Bacillus subtilis/gram), (c) control diet plus 1.2 g/kg diet Kombucha tea (20 % concentration), and (d) control diet plus 10 g/kg green tea powder. The body weight and feed intake were significantly (P < 0.05) increased by the dietary inclusion of the Kombucha tea compared to the control and green tea-fed broilers. However, an improvement in performance traits was observed in broilers fed with the probiotics. Plasma lipids of birds fed the green tea powder diet consisted of lower cholesterol and TG and higher HDL than those of control birds. Protein digestibility was significantly higher (P < 0.05) for birds given the Kombucha tea supplement compared to that of the control birds. The probiotic diet increased (P < 0.05) the villus height/crypt depth ratio and the villus height in the duodenum. Overall, the results in this work show that Kombucha tea and probiotic supplements in feed display growth promoting effects similar to those of traditional antibiotics; therefore, these products might be alternatives to antibiotic growth promoters.