Factors affecting water usage
Water usage by the pigs is influenced by different factors, including environment, management, facilities, and diet. Understanding the factors affecting water usage is important to provide water to meet the requirements while controlling water wastage.
Water flow rate
Low water flow rate increases the time spent at the drinker and discourages optimal water consumption by the pigs. In contrast, high water flow rate increases water wastage. The recommended water flow rates are presented in Table 1.
Water pressure also influences the activation of water delivery devices by the pigs and the amount of water wastage. The recommended water pressure to facilitate activation while controlling water spilling is 20 psi.
Waterer to pig ratio
Waterer to pig ratio of 1:25 is typical for nursery and grow-finishers in the industry. The general recommendation is to have a single waterer for every 10 to 15 pigs, typically in a 1:12 waterer to pig ratio. Providing access to water at the recommendation may improve growth performance of nursery (Sadler et al., 2008) and grow-finish pigs (Vier et al., 2018).
Waterer type and adjustment
Waterer types for pigs are generally categorized as nipples or cups. Both are designed to provide ad libitum water to pigs and there is no evidence that growth or reproductive performance is influenced by waterer type. Yet, waterer adjustments to the proper height for consumption is important to encourage water consumption as pigs grow. Cups and nipples mounted at a 90°angle should be adjusted at shoulder height, whereas nipples mounted at a 45°degree angle should be set at 2 to 3 inches over shoulder height.
There is a wide variation in the amount of water wastage due to waterer type and management. Nipple drinkers are more prone to water wastage than cup drinkers. With nipple drinkers, water spilling goes directly into the manure pit and pigs easily activate the nipple for recreation or by unintentionally leaning on the nipple. Nipple drinkers may require more management of waterer height and water flow to minimize water wastage. With cup drinkers, water spilling flows into a bowl placed beneath the water delivery devices and is available for pigs to drink. However, cup drinkers may also accumulate feed, urine, and feces in the bowl, whereas nipples provide a continuous supply of fresh water for pigs.
Feed form and feeder type
Water consumption is greater for pigs fed meal diets compared to pellet diets, resulting in a similar water to feed ratio when accounting for differences in feed efficiency between the feed forms (Laitat et al., 1999). The use of wet-dry feeders reduces water wastage compared to the use dry feeders and waterers (Brumm et al., 2000).
Water consumption is greater when dietary composition increases the need to eliminate metabolites or surplus nutrients. The increase in water consumption is noticeable when pigs are fed diets with excess salt, proteins, or minerals (Shaw et al., 2006).
The amount of water consumption by pigs varies greatly with temperature, humidity, ventilation, stocking density, flow rate, health status, and stress level. Knowledge of the daily patterns of water consumption by the pigs can serve as an indicator of unfavorable environmental conditions and a predictor of the onset of health challenges (Brumm, 2006).