Further studies of the rate of passage of food through the alimentary tract of pigs

Abstract

1. Four replicated experiments were made to determine the rate of passage of meal through the alimentary tract of pigs on different feeding treatments. In each experiment stained meal was used and the results were expressed by means of excretion curves. From these, mean retention times (R values) were calculated. All the curves were of a similar sigmoid shape.2. A significant inverse relationship was found between the mean retention time and the total weight (meal plus water) of the ration. This relationship was found when (a) the weight of meal was constant and the weight of water was varied, (b) the weight of water was constant and the weight of meal was varied, and (c) the total combined weight of meal and water (at the same ratio) was varied.3. The digestibility of the dry matter and crudec protein in Exps. 1–3 was not altered greatly as a result of the different feeding treatments.4. In Exp. 4, similar rates of passage were found in pigs fed on the two rations of widely different digestibilities.5. The dry-matter content of the faeces of the pigs was remarkably constant over a wide range of water and food intakes when using the same meal.