The effect of citric acid acidification of drinking water on growth performance, cecal pH, and cecal microflora of meat duck

Two experiments were conducted to evaluate the effects of acidification of drinking water with citric acid (CA) on growth performance, cecal pH, and cecal microflora of meat ducks. Preparing tap water containing 5 concentrations of CA (0%, 0.021%, 0.034%, 0.068%, and 0.449%) to lower pH of the solutions from 7.80 (tap water) to 5.45, 4.45, 3.50, and 2.56 was assessed, respectively. A total of 120 1-d-old ducks in Exp. 1, and another 120 15-d-old ducks in Exp. 2 were randomly allocated to 5 drinking water treatments with 6 replicate cages of 4 ducks, respectively. The experimental period was from 1 to 14 d of age in Exp. 1, and was from 15 to 35 d of age in Exp. 2. In both experiments, drinking water administration of incremental concentrations of CA linearly and quadratically reduced (P < .05) water intake of ducks. Feed intake and daily weight gain of ducks in Exp.1 linearly decreased (P < .05), while feed intake in Exp.2 linearly increased (P < .05), and the absolute quantitative level of E. coli (d 35, Exp.2) in the cecum of ducks quadratically decreased (P < .05) as supplementation of drinking water with CA increased. Data obtained from Exp. 1 indicated that ducks from 1 to 14 d of age should not be given acidified drinking water; however, acidified drinking water with 0.068% CA (pH 3.50) can be supplied to ducks from 15 to 35 d of age based on data from Exp. 2.