Water Consumption of Pastured Livestock, from Mother Earth News
Animals on pasture get some moisture from the water contained in grass, but they need sufficient, reliable supplies of clean water to grow and remain healthy. Factors that affect water consumption include weather conditions, diet, activity level and access. The animals’ size and type are important, and physical condition (pregnancy, rapid growth, lactation) also can make a big difference in water requirements.
As a rough guide to how much water you should provide to your livestock, the following table shows typical consumption in winter and summer.
Gallons per day per head:
Chickens (100 birds)
Turkeys (100 birds)
Read more: https://www.motherearthnews.com/homesteading-and-livestock/livestock-waterers-zmaz06aszraw.aspx#ixzz3DhP8pdeE