2017 Volume 65 Issue 1 Pages 11-18
Common carp (mean body weight: 25 ± 5.7 g) were fed three semi-purified diets of different levels of NaCl concentration (0.027%, 0.35%, and 1.75% Na). Feces collected during the initial (day 11-14) and final (day 20-23) phases of feeding were analyzed, and the net intestinal absorption of protein, organic matter, dry matter, sodium, phosphorus, calcium, magnesium, iron, zinc, and manganese was estimated using yttrium as a non-absorbable reference. Fecal Na was similar (0.51-0.65%, dry feces), irrespective of dietary NaCl content. Fecal phosphorus decreased from 0.25% to 0.18% (P = 0.051, final phase), fecal magnesium also decreased (P = 0.018), and fecal protein tended to decrease from 7.63% to 6.75% (P = 0.069, final phase) with an increase in dietary NaCl. The net absorption of dry matter increased from 82.3% to 84.3% (P = 0.017, final phase), and that of organic matter increased from 84.7% to 86.1% (P = 0.037, final phase) with an increase in dietary NaCl. Net absorption or fecal content of calcium, iron, zinc, and manganese was similar, irrespective of dietary NaCl levels. These results indicate that dietary NaCl has minor effects on net intestinal absorption of aforementioned nutrients under the present experimental conditions.
