LAUSR

The purpose of this study was to ascertain the appropriate levels of dietary sodium (Na+ ) and chloride (Cl- ) for 29- to 70-day-old goslings and to investigate the effects of different levels of Na+ and Cl- on the growth performance, water consumption, blood parameters and excreta quality of goslings to provide a reference for the healthy production of goslings. In Experiment 1, a total of 432 29-day-old male Jiangnan White goslings were randomly allotted to nine treatments according to a 3 × 3 factorial design, with six pens containing eight birds per treatment. The goslings were fed diets with three concentrations of Na+ (0.10%, 0.15% and 0.20%) and three concentrations of Cl- (0.15%, 0.20% and 0.25%). The experimental period was 42 days. In Experiment 2, a total of 24 70-day-old Jiangnan White goslings were selected for four treatments (0.10% Na+  × 0.15% Cl- ; 0.10% Na+  × 0.25% Cl- ; 0.20% Na+  × 0.15% Cl- and 0.20% Na+  × 0.25% Cl- ) and housed separately in metabolic cages. The faeces were collected for 3 consecutive days. In Experiment 1, the average daily feed intake (ADFI), average daily gain (ADG) and feed/gain (F/G) ratio of goslings were unaffected by the treatments. However, low levels of Na+ and Cl- significantly reduced the water consumption of goslings in the later growth period (p < 0.05). The average water consumption of goslings fed with 0.10% Na+  × 0.15% Cl- was significantly lower than that of the goslings fed with 0.20% Na+  × 0.25% Cl- (56 days, 1304.2 ml vs. 1471.7 ml; 63 days, 1452.8 ml vs. 1610.8 ml; 70 days, 1540.0 ml vs. 1775.4 ml; p < 0.05). The interaction between Na+ and Cl- (Na+  × Cl- ) had a significant impact on the blood haemoglobin (HGB) and haematocrit (HCT) levels in the goslings (p < 0.05). HGB increased linearly with increasing levels of Na+ . HGB and HCT first increased and then decreased with increasing levels of Cl- . In Experiment 2, Na+ and Cl- levels had significant effects on the excreta moisture content (p < 0.05). Goslings fed with 0.10% Na+  × 0.15% Cl- had a low moisture content of 5.58% compared to the goslings fed with 0.20% Na+  × 0.25% Cl- (87.51% vs. 93.09%; p < 0.05). The levels of dietary Na+ had a significant effect on the retention ratio of Na (p < 0.05), with the value for the 0.20% Na+ group being significantly higher than that for the 0.10% Na+ group (p < 0.05). In summary, different levels of Na+ and Cl- did not affect the growth of goslings. To reduce the water consumption and moisture content of excreta, the Na+ and Cl- levels in the diet can be as low as 0.10% and 0.15%, respectively.