When an emergency swine disease outbreak, such as foot-and-mouth disease (FMD), occurs, it will be necessary to rapidly and humanely depopulate and dispose of infected and susceptible pigs to limit viral replications and disease spread. Methods other than handling individual pigs will be required to achieve the necessary rapidity. Suitable and practical on-farm methods will require depopulating large numbers of pigs at a time outside confinement buildings. The process must be easily implemented with readily available materials and equipment, while providing for the safety and well-being of personnel. Carbon dioxidegas (CO2) is the means of choice, and this study analyzed the methods and requirements for delivering the gas into large volume truck bodies, corrals, dumpsters or other such chambers that may be used. The issues studied included: How the gas should be introduced to achieve the needed spatial distribution; whether plenums are required in the chambers; and the importance of sealing all chamber cracks and edges except around the top cover to limit CO2 dilution and leakage. Analysis was done using computational fluid dynamics (CFD) software, and primary results were verified experimentally. The CFD findings and experimental results are compared, and recommendations are discussed.
Supplementing fossil fuels with solar air tempering for brooding young livestock could reduce energy use and improve indoor air quality. Metal transpired solar collectors (TSC) are effective but too expensive for heating livestock buildings. An inexpensive 12.7 m2 dark grey landscape-fabric-based transpired solar collector (fTSC) was evaluated in a swine nursery with two herds of pigs. A fraction of the fTSC area was underlain with phase change material (PCM) to store excess heat. The Test room with the fTSC was compared with an adjacent identical Control room, each with 120 piglets. The fTSC provided supplemental heating, e.g., with a suction velocity (Vs) of 0.027 m/s during a 9 h period, air temperature was increased by 11.6 °C (mean irradiance of 592 W/m2). Between 4 pm and 9 pm that same day, the PCM increased air temperature by 3.9 °C. The fTSC did not reduce propane use or improve pig performance. Higher Vs, operational changes and controller modifications could improve system performance and reduce cost. Modeling could be used to optimize PCM use. Hence, this very low-cost fabric-based solar air heater offers potential for considerable reduction in heat energy use in livestock barns.