THE NUTRITIONAL THIAMIN STATUS OF LACTATING RATS AND THIAMIN TRANSFERINTO MILK AND OFFSPRING

This study was conducted to determine whether moderate alterations in dietary thiamin concentrations during lactation would influence the bo dy thiamin of lactating rats, and the transfer of thiamin into milk an d to their offspring within a short time of 6 and 13 days. Therefore, after parturiton, rat dams were divided into 6 groups of 8 each, and w ere fed diets during lactation with 0.5, 6, 9, 12, 24 and 36 mg/kg thi amin over a total of 13 dais. Milk was analysed for its thiamin concen tration at day 6 and 13 of lactation. Thiamin status including transke tolase activity in blood and erythrocytes, and thiamin concentration i n blood, liver and carcass were measured at day 14 of lactation both f rom the rat dams and their 13-days old pups. Rats receiving 0.5 mg/kg thiamin in their diet were classified as thiamin-deficient on the basi s of reduced body weight, and transketolase activity in blood and eryt hrocytes, The thiamin requirement during lactation can therefore be as sessed at 6-9 mg/kg. Thiamin concentration in milk ranged between 0.2 and 5.6 mg/kg, and was influenced strongly hv the dietary thiamin supp ly. Also, the body thiamin concentration of the offspring also reflect ed strongly the dams' dietary intake, and the thiamin in milk, respect ively. If the tissues are listed in order of their dose-dependence, a sequence was obtained in which blood was followed by the liver and car cass. However. in all cases, thiamin concentration in the body defined no clear-cut saturation characteristic.