Cooling growing/finishing pigs with showers in the slatted area: Effect on animal occupation area, pen fouling and ammonia emission

摘要

Growing and finishing pigs kept in insulated buildings are often exposed to high ambient temperature during summer. In high-temperature conditions, pigs in partly slatted pens change their behaviour to increase lying on the slatted area and fouling on the solid Hoor area, resulting in increased ammonia emissions. One way to cool the animals is to shower/sprinkle water in the slatted area, allowing pigs to wet their skin to increase heat loss. This study examined the effects of providing showers on pig activity and occupation area in pens, pen fouling and ammonia emission from the room. The investigation was performed in a commercial growing-finishing house with 10 identical rooms, each containing 16 pens for 9-13 pigs growing from 25-30 kg to 115-120 kg. Pigs were introduced into two parallel rooms in the house. During two summers and four batches, one room with showers in the slatted area and one room without per batch were compared in terms of concentrations of carbon dioxide (CO2) and ammonia (NH3), pig activity and occupation area in the pen, pen fouling and NH3 emissions, recorded on four measuring occasions (M1-M4) during the growing period. Gas concentrations were measured using a photoacoustic analyser, pig activity and occupation area detected by machine vision techniques and pen fouling was visually investigated. Climate parameters (air temperature and relative humidity) were logged continuously during the entire growing period. Ammonia emission was calculated from ventilation rate (determined by the indirect CO2 tracer gas method) and the difference in ammonia concentration between outlet and inlet air.