Dietary requirements of sodium and chloride for slow-growing broiler breeds during finisher phase of production

The experiment was conducted to estimate dietary requirements of sodium and chloride for Lingnan yellow chickens from 43 to 63 days of age. A total of 750 broiler males were randomly divided into 5 treatments, and each had 6 replicates with 25 birds per replicate. The control diet was formulated without supplemented NaCl. Dietary treatments 2 to 5 were the control diet supplemented with NaCl and contained equal levels of Na and Cl, 0.1%, 0.2%, 0.3%, and 0.4% of the diets, respectively. The results showed that NaCl supplementation increased body gain, feed and water intake, while improved FCR (P < 0.001). Body gain, serum sodium, and osmolality (OSM) presented a quadratic broken-line regression (R-2 = 0.975, P < 0.05) at 0.09%, 0.1%, and 0.1%, respectively. Serum level of potassium decreased linearly (P = 0.033) with increased dietary sodium and chloride. Feeding a diet with 0.1% sodium and chloride resulted in higher thigh muscle (P < 0.01). The color lightness (L*) of the breast meat decreased linearly (P = 0.009), while the redness increased linearly (P = 0.038) at 0.4 % sodium and chloride. Dripping loss decreased at 0.4% sodium and chloride (P = 0.003). In conclusion, by quadratic broken-line regression model, dietary sodium and chloride requirements to optimize body gain, serum sodium and potassium levels and OSM were 0.09%, 0.10%, 0.10%, and 0.10%, respectively, for Lingnan broiler males as an example for slow-growing broiler breeds from 43 to 63 days of age.