Abstract
Changes in nitrogen (N) balance were investigated in 4-week-old male Wistar rats fed a magnesium (Mg)-deficient diet, in comparison with rats fed a normal control diet. After 42 days of feeding, final body weight, weight gain and food efficiency were significantly decreased in rats fed the Mg-deficient diet. Rats fed the Mg-deficient diet also showed significant decreases in serum Mg concentration, apparent absorption of Mg and Mg retention from 14 days until the end of the feeding period. There was no significant difference in apparent absorption of N between the two groups. At 14 and 42 days of the Mg-deficient diet, urinary N excretion was significantly increased, N retention was significantly decreased, and serum total protein concentration was also significantly decreased. These results suggest that a Mg-deficient diet depresses protein utilization.
