On the influence of diet on the retention time of food in the digestive tract of cows

Authors

• Aarne Mäkelä Department of Animal Husbandry, University of Helsinki
• Liisa Liakka Department of Animal Husbandry, University of Helsinki

DOI: https://doi.org/10.23986/afsci.71535

Abstract

The retention times of dry matter and its constituents in the digestive tract of cows on hay+sugar beet pulp (5 cows) and cows fed on hay+swedes (8 cows) are compared with the retention times pertaining to cows fed on hay+concentrate or hay only. The following conclusions were reached; On a hay+sugar beet pulp diet the mean retention time of dry matter in the reticulo-rumen, and the retention times of lignin in the reticulo-rumen, in the whole digestive tract, and in the digestive tract following the reticulo-rumen are of the same magnitude as the corresponding retention times on a hay+concentrate diet (figs. 1, 2, 5, and 6). The mean retention time of membrane substances in the reticulo-rumen seems to be shorter and that of valuable N-free nutrients in the reticulo-rumen longer than the corresponding retention times on a hay+concentrate diet (figs. 3 and 4). On a hay+swede diet the mean retention times of dry matter and membrane substances in the reticulo-rumen are of the same magnitude as on a hay+concentrate diet (figs. 1 and 3). The mean retention time of valuable N-free nutrients in the reticulo-rumen and, in abundant feeding, the retention times of lignin in the reticulo-rumen, in the whole digestive tract, and especially in the digestive tract following the reticulo-rumen are shorter than on the hay+concentrate diet (figs. 2, 4, 5, and 6). On the hay+sugar beet pulp and the hay+swede diets the retention times are in general of the same magnitude. However, the retention time of membrane substances in the reticulo-rumen is shorter and that of the valuable N-free nutrients considerably longer on a hay+sugar beet pulp than on a hay+swede diet. Replacing a certain amount of hay by concentrates, sugar beet pulp or swedes on a dry matter basis seems to have no effect on the mean retention time of dry matter in the reticulo-rumen. However, a retarding effect on the rate of passage of typical hay constituents (lignin and membrane substances) and an accelerating effect on that of valuable N-free nutrients characteristic of concentrated foods was observed. The said replacing accelerates the rate of passage of lignin in the disgestive tract following the reticulo-rumen on a hay+swede diet.