Abstract
1. Gastrointestinal size, intestinal absorption of glucose and L‐methionine, and intestinal endogenous nitrogen in Pekin ducks were measured after the birds were subjected to force‐feeding with excessive amounts of a diet based on maize or barley for 12 d.
2. Force‐feeding significantly increased the weight and area of the crop, the weight of the proventriculus, the length and area of the jejunum and ileum, but decreased the weight of the gizzard and the thickness of its caudodorsal thick muscle. Feeding a barley‐based diet also decreased the thickness of caudodorsal thick muscle of gizzard.
3. Force‐feeding enhanced the absorption rates (μmol/cm2) of glucose and L‐methionine in both jejunum and ileum. Ducks fed on a maize‐based diet showed a slightly higher absorption rate of glucose compared to those fed on a barley‐based diet.
4. Force‐feeding caused a significant increase of endogenous non‐protein nitrogen (μg/cm2/h) in both jejunum and ileum and a slight increase of endogenous protein nitrogen in the jejunum.