Intake of Water Containing Condensed Tannin by Cattle and Sheep

Abstract

Ingestion of small amounts of condensed tannin (CT) by ruminants can prevent bloat, improve nitrogen retention, and reduce excretion of urea, a precursor of ammonia and the greenhouse gas nitrous oxide. Because grasses and many forbs don’t contain CT, it is desirable to find a reliable way to have ruminant livestock ingest small amounts of CT when they consume high-quality forage. Putting CT in their drinking water may be a reliable approach, but only if all animals drink enough to meet their requirements for water. Therefore, objectives of this study were to determine the amount of variation in intake of water containing different amounts of CT when this was the only water available, and if cattle and sheep would drink water with CT in it if offered tap water simultaneously. Animals were penned or pastured individually, fed twice daily (first cattle and sheep trial) or grazed (second cattle trial) and had ad libitum access to tannin water, tap water, or both. Liquid intake was measured daily. Steers drank tannin solutions (mean daily intake 49.7-58.3 kg), but variation in intake among steers was higher than for tap water (SD were 44%-58% greater for the two most concentrated tannin solutions). At the highest concentration of tannin, steers ingested 2.3% of their daily feed intake in CT. During most of the preference trial, steers preferred water over tannin water when offered both simultaneously (P < 0.002), but drank some tannin water each day. Sheep drank tannin solutions, but individual variation in tannin solution intakes were greater than for tap water. Placing CT in water of cattle and sheep may be a useful way to put small amounts of CT in them. However, they will likely drink less tannin water if normal water is available.