INFLUENCE OF WHEAT BRAN AND ALFALFA MEAL ON THE THIAMIN METABOLISM OFSOWS PROVIDED WITH A SUBOPTIMAL THIAMIN SUPPLY

Two experiments were designed with 12 adult non gravid sows in each of three groups to determine the influence of increasing supplements of wheat bran (0, 225, 675 g/day) and alfalfa meal (0, 575, 1150 g/day) i n a low thiamin compound feed on fecal and urinary thiamin excretion, thiamin balance (=intake minus excretion), availability of native or b acterially synthesized thiamin, and on the extent of bacterial synthes is. The experiments were carried out in two series with sows weighing 180 kg, on average. Fecal thiamin concentration, which was not influen ced by the fibre supplements, amounted to 10-11 mu g/g dry matter, whe reas total excretion increased with each supplementation. More than 95 % of the excreted thiamin was excreted via faeces. Fecal thiamin conce ntration was similar when the same quantities of wheat bran and alfalf a meal were given. The bacterially fermentable substances from wheat b ran and alfalfa meal induced a higher bacterial thiamin synthesis than with pectin. The availability of wheat-bran thiamin was better than t hat of alfalfa-meal thiamin. From the results of the biochemical analy ses (thiamin concentration in blood, ThDP-effect) it was calculated th at thiamin maintenance requirements of sows can be met by 1.20 mg thia min/d.