Nutrient digestibility response to graded dietary levels of sodium chloride in weanling pigs

BACKGROUND: Sodium (Na+), chloride (Cl-) and phosphorus (Pi) are involved in a number of metabolic and physiological processes in the body, and these mineral elements must be supplied to the animal via the diet. The intention of this study was to evaluate the effect of dietary supplementation with different levels of sodium chloride (0.1, 0.2, 0.3, 0.4, 0.5 and 0.6% NaCl) on apparent and true P digestibility (APD and TPD) and dry matter (DM), crude protein (CP) and calcium (Ca) digestibility in weanling pigs. RESULTS: Dietary NaCl had a quadratic effect on both APD and TPD (P < 0.05) but not on DM, CP and Ca digestibility (P > 0.05). At an NaCl concentration of 0.41% the APD and TPD values were 41.5 and 53.3% respectively. CONCLUSION: These results suggest that a high level of dietary Na+ may enhance P absorption and improve its digestibility by coupling Na+ transportation to Pi absorption via the energy-requiring Na+/P-i co-transporter. (c) 2008 Society of Chemical Industry.