Essential Oils as Feed Additives for Reducing Fungal Load and Improving Poultry Health

Abstract

Fungal contamination of the feed is one of the most significant problems which can impact on poultry health, productivity and feed safety and this is related to the risk of mycotoxin exposure. The present study aimed at assessing the effect of dietary essential oils on fungal load, mycotoxin concentrations, growth performance, antioxidant status, immune responses, gut microbiota and gut morphology in broiler chickens. The feeding experiment lasted 42 days and 240 broilers were distributed equally into four dietary treatments (six replicate pens per treatment): Control, oregano essential oil, thyme essential oil, or a blend of both essential oils. Dietary essential oils showed a reduction in total fungal load and Aspergillus spp. contamination, the most significant of which was seen in the birds fed with EO blend. The concentration of AFB1, OTA, DON and ZEN was also found to be lower in the groups supplemented with essential oil compared to the control. The supplementation with essential oils increased final body weight, body-weight gain, average daily gain and feed conversion ratio without having any significant effect on feed intake. The antioxidant response was strengthened with an increase in SOD, CAT, GSH-Px, T-AOC and a decrease in MDA levels. The immunoglobulin levels were raised, and the levels of IL-6 and TNF-α were lowered. Essential oils also enhanced villus height, VH:CD ratio, beneficial bacteria and expression of genes related to intestinal barrier function, such as MUC2, ZO-1, and OCLN. EO blend tended to give the most significant responses. In summary, the results suggest the potential for essential oils to offer several benefits, including their ability to enhance the safety of feed, antioxidant activity, immune regulation, intestinal health, and broiler productivity. Further controlled studies are recommended to confirm these effects and to determine optimum inclusion rates for application in poultry production.