Metabolic Water as Percentage of Total Water Intake

Correct Answer: 5–10%

Metabolic water — produced during oxidation of nutrients — comprises 5–10% of the total water intake of domestic animals. Despite its small proportion, it plays a critical role in water balance, especially in arid environments.

Sources of Water in Animals

• Drinking water: The largest source (~70–80% of total)
• Preformed water in feed: Succulent fodder = 80–90% water; hay = 12–14% water (~15–20% of total)
• Metabolic water: 5–10% of total water intake

Special Adaptations

Camels minimise water loss and maximise metabolic water by: (1) Oxidising hump fat (fat = 1.07 g water/g oxidised), (2) Tolerating large body temperature fluctuations to reduce sweating, (3) Producing very concentrated urine and dry faeces.

Water Requirements of Cattle

Adult cattle need 3–5 litres of water per kg of dry matter intake.