Effects of drinking water supplemented with apple vinegar, essential oils, or colistin sulfate on growth performance, blood lipids, antioxidant status, intestinal morphology, and gut microflora of broiler chickens

With rising concerns about antibiotic resistance and its consequences on public health, the identification of safe and effective alternatives to antibiotics in the poultry industry has become increasingly critical. This study aimed to evaluate the effects of supplementing drinking water with apple vinegar and essential oils, compared to an antibiotic growth promoter, on the growth performance, serum lipid profile, antioxidant status, intestinal morphology, and gastrointestinal microflora population of broiler chickens. A total of 240 one-day-old male broiler chickens were randomly assigned to four treatments, each consisting of six replicate pens with ten birds per pen. The broiler chickens received the following experimental treatments: normal drinking water without additives (control) and drinking water supplemented with antibiotic (0.25 ml/L), apple vinegar (1 ml/L), and essential oils blend (0.5 ml/L). The results showed that adding antibiotic or essential oils blend to drinking water improved body weight gain and feed conversion ratio throughout the entire rearing period (P < 0.05). The serum levels of cholesterol and low-density lipoprotein in broilers that received apple vinegar or essential oils blend were lower than those in the control and antibiotic groups (P < 0.05). The essential oils blend treatment significantly increased the activity of glutathione peroxidase and superoxide dismutase in the serum of broiler chickens compared to the other treatments (P < 0.05). Furthermore, adding essential oils blend to the drinking water increased villus height and villus height to crypt depth ratio in the jejunum of broilers (P < 0.05). The broiler chickens in the apple vinegar and essential oil blend groups also exhibited a lower population of Enterobacteriaceae and a higher count of lactic acid bacteria in the ceca (P < 0.05). In summary, the addition of essential oils blend to the drinking water of broiler chickens has beneficial effects on production performance and can serve as an effective alternative to antibiotic growth promoters.