Water as a Nutrient

Knowledge Nuggets

• Water is the single most important nutrient for livestock. Cattle can live for long periods of time without food, however without water, death can occur in a matter of days. Water comprises 70% of lean adult animal body.

• Water is involved in virtually every physiological process. Water is a medium for transporting nutrients, waste material, hormones and other chemical messengers, as well as food along the gastrointestinal tract. It helps to regulate body temperature, acts as a lubricant for skeletal joints and is a component of many basic chemical reactions.

• Water requirements for beef cattle increase in hot conditions. Water consumption increases by 235% when temperatures increase from 0 Celsius to 32 Celsius. Additional water will be required if a wind is blowing as well.

• Pregnant cows increase water consumption in the last trimester of pregnancy. Water intake is 50% higher than for non-pregnant animals. Lactating cows consume additional 0.87 kg water for every litre of milk produced over and above what is needed to maintain body function.

• Feeding dry hay or silages with 65% moisture content influences total water consumption by animals. The wetter the feed, the lower the amount of water consumed. Higher fibre feeds also increase water intake.

• Cows can eat fresh, loose snow to obtain their water needs. It can take up to 2 days for cows to become accustomed to snow. To determine if cattle are consuming enough snow to meet water requirements, monitoring their feed intake.

• Unfortunately, the quality of the water provided for livestock is often overlooked. Water quality is assessed for bacteria and mineral levels in the water. The major difficulty is establishing levels at which animal health, welfare and productivity may be impaired.

• Water quality is assessed for pH, total dissolved solids (TDS), and nitrates and nitrites. pH values less than 7 are increasingly acidic and values greater than 7 are increasingly alkaline. TDS is the main indicator whether mineral levels will be a problem. Water with a TDS of less than 1,000 mg/L is acceptable for all classes of livestock. Above that level, the effects may range from no noticeable effect to temporary diarrhea to decreased productivity. Nitrates and nitrites in water react with hemoglobin in the blood making it incapable of transporting oxygen.

• Water may contain bacteria, viruses, protozoa and parasite eggs. Water chlorination will remove harmful bacteria and other microorganisms. Protozoa and enteroviruses are more resistant to chlorination than bacteria.

• Producers wanting information on how to take water samples and where to send samples should contact their local water specialist or health unit.