Refer to the following Table for estimated water needs of various classes of swine. Table: Water consumption by pigsClass gallon/pig/dayGestating sow 2 to 3Lactating sow 4 to 5Starting pig (13 to 45 lb) .5 to 1Growing pig (45 to 130 lb) 1Finishing pig (130 to 250 lb) 1.5 to 2In general, a pig will consume 1/4 to 1/3 gallon of water for every pound of dry feed. The water requirements are variable, with the need for water increasing when a pig has diarrhea or experiences warm or hot environmental conditions. Diets high in salt or protein or other ingredients whosebyproducts of digestion and metabolism are excreted via the kidney also increase water needs. Lactating sows must have unlimited access to water if they are to produce milk adequately. Suckling pigs older than 10 to 14 days of age need water in addition to that in milk for optimum performance. With typical nipple drinking devices, the rate of delivery (cups/minute) has little effect on performance as long as a minimal delivery rate is achieved with the device. Pigs generally make up for reduced delivery rates by spendingmore time at the drinking device. Suggested minimum delivery rates for nipple drinking devices are:starting pigs ? 1 to 1.5 cups/minutegrowing-finishing pigs ? 2 to 3 cups/minutesows and boars ? 3 to 4 cups/minuteFor all classes of swine that are housed in pens, we recommend that at least one nipple drinker device be provided for every 15 pigs in the social group, with a minimum of 2 devices per group. We recommend one nipple drinker device for every 10 pigs in the nursery. Recent research suggests that if water waste is a concern, the use of wet/dry feeders or bowl drinkers may result in which the nipple drinker is incorporated in the feed bowl of the feeder as the sole source of water may result in up to a 40% reduction in slurry volume. Newer designs of drinking devices may also reduce water wastage when compared to traditional nipple drinking devices. Consideration of the need for wasted water for proper functioning of manure transfer and storage devices is a consideration in drinker device selection.