Diurnal and daily variations in the composition of cow faeces

Authors

• Maija-Liisa Salo Department of Animal Husbandry, University of Helsinki
• Ulla Peltola Department of Animal Husbandry, University of Helsinki
• Kaija Kotilainen Department of Animal Husbandry, University of Helsinki

DOI: https://doi.org/10.23986/afsci.71775

Abstract

The work is concerned with the diurnal and daily variations in the composition of cow faeces. Samples were taken from four dairy cows five times a day during the course of three days. The cows were fed on roughage and concentrates. The faecal samples were analysed for hemicellulose, cellulose, lignin, crude protein, total ash and the ash soluble in 1N HCI. The following results were noted: Large variations occur in the composition of cow faeces. The largest variations relate to the cellulose, crude protein and total ash, whereas the content of lignin varies only little. Diurnal regularity was not noted. A close positive correlation was noted between the contents of hemicellulose and cellulose, as well as between the crude protein and the ash contents. A close negative correlation existed between both groups of carbohydrates and the crude protein, both carbohydrate groups and the ash, and between the crude protein and crude lignin. A high ash peak, attributable to sparingly soluble ash, was noted on several days. These ash-rich samples always have a high content of crude protein but a low content of carbohydrates. The digestibilities of the cellulose and crude protein were inversely related and varied during the same day of sampling within a range of as much as 12—13 percent units. The digestibility and rate of feed passage cannot be reliably evaluated by a grab sampling technique, at least not in instances when the cows are receiving both roughage and concentrates. As a possible reason for the variations it is suggested that the feed leaves the reticulorumen as different fractions. Shortly after the feeding, the material rich in concentrate moves on, whereas later mainly roughage material passes further into the alimentary tract. In the large intestines the former fraction results in a more intensive growth of bacteria, and the faeces originating from it contains a relatively higher proportion of bacterial matter.