The experiments were carried out to determine sodium requirements for light (LS) and egg-brown (EBS) pullets from 7 to 12 weeks of age. It was used a completely randomized design according to a 6x2 factorial (sodium levels: 0.04; 0.10; 0.16; 0.21; 0.27 and 0.32% X 2 strains), with five replicates of six pullets per experimental unit. Feed intake, water intake, daily weight gain, feed: gain ratio, rectal temperature, and comb size were evaluated, as well as feces dry matter and humidity. In the two experiments, there was no interaction (P>0.05) between sodium levels (SL) and strains on the studied variables. Feed intake was not affected by LS, but it was greater in EBS than in LS birds (P <0.05). LS had significant effects on daily weight gain and feed: gain ratio according to the quadratic model, and comb size was greater in LS compared to EBS birds. The increase in dietary sodium levels increased water intake and feces humidity, whereas feces dry matter decreased. Rectal temperature was not affected by the treatments. For SL and EBS, it is recommended 0.22% Na or a daily intake of 123 and 140 mg of sodium, respectively, from 7 to 12 weeks of age.
Sodium bicarbonate; performance; electrolyte balance; aviculture
