The Effect of Supplementation with Organic Acid and Oregano Oils in Drinking Water on Pekin Duck Growth and Welfare

This study evaluated duck growth, health, and welfare in response to water supplementation with organic acid (OA) and oregano oils (OOs) in Pekin duck. The treatments used in this study included a control (CON) treatment with no water additives given, an OA treatment (ProPhorce Exclusive NC®), and an OO treatment (Nubiotic 4X Concentrate®). The OA and OO improved the feed conversion ratio (FCR) and body weight (BW) (p < 0.01) compared to the control (CON). Both OA and OO showed differences (p < 0.05) in villus height and crypt depth compared to the CON. But only OA showed an increase (p < 0.01) in villus height and villus height/crypt depth ratio. On D 35, the total plasma corticosterone levels, heterophil-to-lymphocyte ratios, and asymmetry scores for OA and OO were decreased (p < 0.05) compared to CON, indicating lower stress susceptibility. The pH levels of OA ceca and jejunum were lower (p < 0.05) compared to CON. Tibia breaking strength was increased (p = 0.02) for OA compared to CON, while no differences were found with OO (p > 0.05). In conclusion, these experiments indicate that OA and OO can be used to improve duck growth, feed efficiency, stress susceptibility, and bird welfare.