Dry matter and nitrogen in the duodenal contents of growing pigs: a discrepancy explained.

1. Discrepancies between the results obtained from experiments on pigs with re-entrant duodenal cannulas have been investigated with reference to diet, cannula site and collection procedure. 2. The results obtained from a sealed automatic collection system were different from those obtained from an open manual method and it was concluded that the maintenance of gut intra-luminal pressure in the automatic system was the causative factor.