Water is an important factor for the survival of the body, and it is the basic substance of blood, intercellular and intracellular. As a solvent, water ensures the metabolic utilization of nutrients and the discharge of metabolic wastes; maintains a relatively stable internal environment by controlling the pH, osmotic pressure and electrolyte concentration of body fluids; participates in thermoregulation; acts as a lubricant in the body. Water is also a constituent of eggs.​​
1. Water source The chicken body's need for water can be met by the endogenous water produced by the water in the feed, the drinking water and the final product of nutrients. Feed water: All kinds of feeds contain water, such as green fodder with water content of 70%-90%, cereals 12%-14%, cakes 10%, roughage 12%-20%. Supplement body water. Drinking water: In order to keep chickens at the best growth rate and production performance and improve feed utilization, it is necessary to ensure clean drinking water. In general, the water intake of chickens is related to the feed. In the case of feeding compound feed, the water intake of chickens should be 2-2.5 times the amount of dry matter consumed, and 1.5-2 times that of laying hens. Endogenous water: water is formed during the metabolism of nutrients in the body. The oxidation of 1 gram of fat, carbohydrate and protein in the body will produce 1.19 grams, 0.56 grams and 0.45 grams of water, respectively. The amount of endogenous water is very small, which cannot meet the water needs of chickens.​​
2. Hazards due to water shortage Chickens have a continuous demand for water, and fresh drinking water must be supplied adequately. If the supply is not timely, it will affect production and health. When the chicken body loses 10% of its water, it will cause death. Laying hens have a more obvious response to water shortage. If water is cut off for 24 hours, the egg production rate will drop by 30%; if water is cut off for 48 hours, they will die seriously. Restriction of water intake by 20%-50% for broilers will seriously affect production and feed remuneration.​​
3. Factors affecting the amount of drinking water Fresh drinking water is an important way to meet the water demand of chickens. The amount of water a chicken needs to drink is also affected by many factors. (1) Ambient temperature: Ambient temperature is one of the factors affecting the water demand of chickens. When the ambient temperature exceeds the critical temperature (14.5-25.5°C), the chickens begin to pant, the water evaporated from the lungs increases, the water intake increases significantly, and the feed intake decreases. With the evapotranspiration of water from the lungs, the water excreted by the kidneys also increases, resulting in soft feces. This mechanism is necessary for chickens to maintain life within the necessary limits and to maintain normal body temperature. When the temperature is above 21°C, for every 1°C rise, the amount of drinking water increases by 7%, from 21°C to 32°C, the water intake doubles. When the temperature of laying hens rises from 10 ℃ to above 32 ℃, the water consumption can be doubled. The water consumption at 32°C and 37°C was 2 times and 2.5 times that at 21°C, respectively. (2) Production goals: the higher the egg production rate, the greater the chicken water demand. Laying hens drink more water than broilers, and their ratio to feed consumption is 2:1 and 1.5:1, respectively. (3) Other factors: Chickens are extremely sensitive to saline and hate warm water. Water intake increased when dietary salt, fiber, and protein were increased. Enzyme preparations and trace elements are added to the diet, and the water intake is increased.​​
4. Water quality In production practice, it is necessary to pay attention not only to the quantity of drinking water supplied to chickens, but also to the quality of water. Drinking water requires freshness, heavy metal content not exceeding drinking water standards, and no pathogenic bacteria and pesticide residues. Because unqualified drinking water and undrinkable water will interfere with the absorption of nutrients in the feed and the exertion of antibacterial drugs, it will even affect the appetite, cause diarrhea, and in severe cases, the chickens will become sick or even die.