Water consumption and wastage behaviour in pigs: implications for antimicrobial administration and stewardship

Publication summary

In animal agriculture, when antimicrobial drugs are administered to groups of animals it is often done so through the animals’ drinking water. Therefore, estimating how much water each animal will consume is important and water wastage by the animals can be a confounding factor when in-water dosing antimicrobials. Inaccurate estimates of water wastage can result in either under-dosing or over-dosing the antimicrobial drug. While many pig farms use piped drinking water systems in farm buildings, systems are lacking that provide veterinarians and farm managers with easily interpretable data on water consumption and wastage behavior, which can vary over time and between each group of pigs even in the same building. This prospective, observational study measured and analyzed water use and wastage patterns of a group of 15 finisher pigs on a daily and hourly basis over 27 days under normal farm conditions, with the goal that these data could be used to guide in-water antimicrobial dosing and improve pig health and antimicrobial stewardship.  

Who this is for

• Veterinarians, particularly swine veterinarians
• Pork producers
• Those working on antimicrobial stewardship in animal agriculture

Key Findings

• Water wasted by the group of pigs each day, as a proportion of the total water used, was stable day-to-day over the study period, as were the ratios of water used:feed consumed, and water consumed:feed consumed.
• Patterns of daily water use and wastage of pigs were accurately modeled using a Bayesian statistical method. The patterns were closely aligned and uni-modal, peaking at 1400–1700, with a slightly greater proportion of the water used wasted during hours of higher water use.
• It is feasible to quantify the daily water use and wastage patterns of a group of pigs and use them prior to each in-water dosing event to perform more accurate dosing calculations and optimize the dosing regimen, thereby improving in-water antimicrobial dosing efficacy and stewardship on pig farms.
• During an in-water antimicrobial dosing event during this study, the median water wastage rate measured in the study pen was 38%, which was 7% less than the value of 45% wastage factored into the dosing calculations prior to the in-water dosing event conducted in the building. Pigs would therefore have consumed a larger dose of the  antimicrobial than was targeted (9 mg/kg vs. the target of 8 mg/kg), equating to 1.125 of the target dose or an over-dose of 12.5%.
• While results of this study are specific to the group of pigs studied and further study is warranted to account for additional drinking behavior and environmental parameters, as well as studies in different pig life stages, such a water metering system and analyses could help to reduce the quantities of antimicrobials used and disseminated into the environment as well as be used to identify and implement water-saving strategies on animal agriculture farms.