Effects of Dietary Phytobiotic Mixtures on Growth Performance, Nutrient Digestibility, Intestinal Histomorphology, Cecal Microbiota, and Antioxidant Status in Fattening Ducks

This study aims to evaluate the effects of two phytobiotic mixtures on performance, nutrient digestibility, histomorphology, microbiota, and antioxidant status in fattening ducks. A total of 180 day-old male mixed-type ducks were randomly assigned to three dietary groups: a control group receiving a basal diet, and two treatment groups (PM1: commercial phytobiotic formulation containing menthol, eucalyptus oil and turmeric leaf oil as key ingredients and PM2: commercial phytobiotic formulation containing garlic oil as a key ingredient) supplemented at 250 g/ton of feed. Ducks were reared for 49 days with six replicates of ten ducks. Performance parameters, including body weight (BW), body weight gain (BWG), and average feed intake (AFI), were significantly improved in phytobiotic groups (p ≤ 0.05). Apparent digestibility of dry matter, crude protein, ether extract, and starch remained unaffected (p > 0.05). Histological analysis showed no significant differences in villus height (VH) or crypt depth (CD). However, cecal microbiota culture-based analysis revealed increased total anerobic bacteria and Lactobacillus counts in PM1 and PM2 (p ≤ 0.05). Antioxidant status demonstrated reduced MDA levels and elevated total phenolic content (TPC) and total antioxidant capacity (TAC) in breast and thigh tissues of treated ducks. Overall, phytobiotic supplementation improved performance and microbiota balance, supporting the potential application of these phytobiotic formulations at the inclusion level of 250 g/ton in fattening ducks’ nutrition.