**2.1 Drinking water**

Drinking water constitutes the greatest source of water to poultry and it is made available in drinkers [1]. It is of great concern to poultry producers due to its great variability in quality and potential for contamination [5]. It could be from tap, stored in rooftop tanks, or underground (well) water [7]. The physico-chemical parameters established as indicators of water quality include taste, color, odor, pH, electrical conductivity (EC), hardness, alkalinity, salinity, and presence of cations and anions [14]. High-quality drinking water has been defined as water that contains inclusions, which promote vitality and lack inclusions causing morbidity and mortality [15, 16]. Because no water in nature is 100% pure, different water sources will have varying degree of water inclusions, which directly or indirectly affect poultry performance and welfare [17].
