The experiment was conducted to estimate the ideal dietary sodium (Na) and chloride (Cl) level for broilers during day 1 to 21 using a corn-soybean meal diet under a dietary Na:Cl ratio of 1:1. A total of 490 1-d-old Arbor Acres male broilers were randomly allotted by body weight to one of seven treatments in a completely randomized design. Each treatment consisted of seven replicate cages with 10 chicks per cage. Broilers were fed a Na and Cl-unsupplemented corn-soybean meal basal diet (control, containing 0.02% Na and 0.08% Cl) and the Na and Cl-supplemented basal diets containing 0.14%, 0.20%, 0.26%, 0.32%, 0.38%, and 0.44% Na and Cl levels, respectively for 21 d. The results indicated that average daily gain, average daily feed intake, blood partial pressure of CO2 and concentrations of HCO3-, total CO2, Na+, Cl-, base excess and anion gap, tibial ash, and ash Na contents of broilers were affected (P < 0.001) by dietary Na and Cl level, and increased linearly (P < 0.001) and quadratically (P < 0.001) with increasing Na and Cl levels. Feed/gain ratio, mortality, blood K+ concentration, serum osmotic pressure and K+, glucose and uric acid concentrations as well as heart, liver, and kidney indices of broilers were affected (P < 0.01) by dietary Na and Cl level, and decreased linearly (P < 0.001) and quadratically (P < 0.001) with increasing Na and Cl levels. The estimates of dietary optimal Na and Cl levels were 0.07% to 0.16% according to the best-fitted broken-line or asymptotic models (P < 0.001) of the above sensitive indicators. Therefore, the optimal dietary Na and Cl level was suggested to be 0.16% to support all of the above Na and Cl metabolic requirements of broilers fed the corn-soybean meal diet during day 1 to 21, which is lower than the 0.20% recommendation by the Chinese Feeding Standard of Chicken (2004).
Keywords: blood gas parameter; broiler; optimal dietary sodium and chloride level; organ and tibial parameter; serum physiological and biochemical indicator.
Sodium (Na) and chlorine (Cl) are essential minerals for poultry. The current Na and Cl requirement of white-feathered broilers during day 1 to 21 recommended by the Chinese Feeding Standard of Chicken (2004) was based on previous literature published more than 50 yr ago. The purpose of the present study was to examine the effect of different dietary Na and Cl levels on the growth performance, mortality, average daily water intake, excreta water content, blood gas parameters, serum physiological and biochemical indicators, organ indexes, intestinal morphology, and tibial parameters, to assess the optimal dietary Na and Cl level of broilers using the conventional corn-soybean meal diet during day 1 to 21. The results suggest that the optimal dietary Na and Cl level would be 0.16% for broilers fed the corn-soybean meal diet from 1 to 21 d of age, which is lower than the 0.20% recommendation by the Chinese Feeding Standard of Chicken (2004).
© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science.