Effect of different non-chloride sodium sources on the performance of heat-stressed broiler chickens

Abstract

1. One hundred and eighty 1-d-old broiler chicks were used to evaluate the effect upon broiler performance during severely hot summer months of three different sodium salts: sodium bicarbonate (NaHCO₃), sodium carbonate (Na₂CO₃) and sodium sulphate (Na₂SO₄), in starter and finisher diets having an identical electrolyte balance (DEB) of 250 mEq/kg.

2. The non-chloride sodium salts were added to contribute the same amount of sodium and were substituted at the expense of builder's sand in the basal diets containing common salt (NaCl) as Na and Cl source.

3. Each diet was fed to three experimental units having 15 chicks each until 42 d of age. Severe heat-stress conditions, maintained in the rearing room, were indicated by high average weekly room temperature (minimum 29·3°C; maximum 38·0°C).

4. Diets containing sodium salts gave better body weight gain, feed intake and feed to gain ratio than the control diet. Sodium salts also enhanced water intake as well as water to feed intake ratio. This effect was more pronounced in broilers fed NaHCO₃ supplement (with NaCl in the basal diets).

5. The increased water intake resulted in lower body temperature in heat-stressed birds fed NaHCO₃ supplemented diet than in birds fed other sodium salts. A lower mortality rate was noted with NaHCO₃ (15·15%), Na₂CO₃ (13·64%) and Na₂SO₄ (15·15%) supplements than with the control (33·33%) treatment.

6. Better carcase and parts yield were observed in sodium supplemented broilers. Sodium salts reduced the alkalotic pH and enhanced the blood sodium content, which ultimately improved the blood electrolyte balance and overall performance of heat-stressed broilers.

7. Supplementing broiler diets with sodium salts improved the live performance of heat-stressed broilers and better productive performance was noted with NaHCO₃ than other sodium supplements.