Watch Water Consumption during Hot Weather
Dairy Pipeline: August 1997
Charles C. Stallings
Extension Dairy Scientist, Nutrition
Having plenty of clean water available for lactating cows is especially important this time of year. In a study we conducted during July through November we found that first calf heifers producing about 50 lbs. of milk per day consumed an average of 165 lbs. of water or 20 gallons (8.345 lbs. per gallon) per day. This was approximately 15% of body weight. Total water intake, including water in the feed, was approximately 200 lbs. or 19% of body weight. Larger cows producing at high levels will consume more water. Cows producing in excess of 100 lbs. per day would be expected to consume more than 30 gallons during the hotter times of the year. Therefore, most herds or groups of large breed cows will consume 20 to 30 gallons of water a day. If lactating cows do not have adequate amounts of water, milk production will suffer. Water intake will also vary with dry matter intake, moisture content of ration, and salt consumption. Some common sense suggestions are to locate waterers in the shade, provide access to waterers after milking, keep waterers clean, and make sure there is enough time and space for cows to consume water during hotter times of the day. One suggestion is to provide 2 feet of trough space for every 15 cows. Cows will tend to drink more warm water than cool, but cool water will be more effective in lowering cows body temperature during hot weather. My observation is that herds that are getting a lot of milk from their cows have an abundant, clean supply of water.