Water is the most important nutrient of the broiler. Although a bird can survive for several weeks without food, it will die after a few days without water.
Water consumption in the broiler is an effective management tool to monitor flock progress as it is directly correlated to food intake. The correlation is estimated to be 0.98 (Lott and co-workers 2003) which means that, when water consumption changes 98% of the time food consumption will change correspondingly. By accurately monitoring water intake the farmer can get a good idea of food consumption.
Birds will consume 1.6 - 2 times as much water as food – on a kg for kg basis. In its lifetime, a 2-3kg broiler will drink 8 – 8.5kgs water (at normal temperatures) compared to eating +/- 5 kg food. An estimate of daily water requirement at normal temperatures (25°C) can be worked out by taking the age of the bird in days and multiplying by 5.7g. (Pesti and co-workers 1985)
Increase in temperature will affect water intake, particularly after day 18, as the birds will consume more water to cool themselves. The following table gives a rough guide of water intake in litres/1000 broilers by age in weeks.
AGE (WKS)10° C21.1°C32.2°C37.8°C
When tracking water and feed consumption it was noted (G Tabler) that if water intake dropped one day, it usually increased correspondingly the next day. It is thought that a one day variance in water intake is not cause for concern as the birds seem to make up the difference the next day. However, if water intake remains depressed for 2 or more days this indicates a problem, which may include the following:
•    Sick birds
•    Drinker height (too low or too high)
•    Air locks in the drinking line
•    Clogged drinkers or nipples
•    A dramatic change in light intensity or temperature
•    Changes in daylight hours (not an issue in Zimbabwe)
•    Insufficient pressure in water lines.
•    Feed changes or feed outages.
•    Change in additives or treatments in water
•    Insufficient drinkers for the number of birds.
Watering Systems
•    In nipple watering systems the requirement is 1 nipple per 10 – 12 birds at 5 weeks.
•    Chick fonts – allow 2/100 birds
•    Bell drinkers – 1/100 birds
Birds should not have to walk more than 1 metre to reach water so allow adequate spacing of drinkers.
REF:     Dr S Watson , Dr G Tabler 
P Jackson for table.