The production of pig meat and poultry is severely affected by heat stress. Recent publications in farmer magazines show the importance even for Austria today. For the US the economic loss for poultry (broilers, laying hens, and turkeys) are in the range between 130 to 170 106 US$ per year, for pigs about 300 106 US$ per year (St-Pierre et al., 2003). In temperate climate regions like Middle Europe these animals are predominantly kept in confined housing systems (APCC, 2014; Integrated Pollution Prevention and Control (IPPC), 2003), which are the source of much of the world’s poultry and pig meat production (Thornton, 2010).
There are only few investigations of the impact of climate change on confined livestock houses. Most of the studies are dealing with ruminants kept on grassland and the emission of greenhouse gases. The effect of climate change on intensive livestock was not in the focus of interest (e.g. AnimalChange, EU-FP7 http://www.animalchange.eu/). In many cases confined livestock keeping is not seen as vulnerable to climate change (e.g. Skuras and Psaltopoulos, 2012), because the indoor climate is controlled to some degree. This assumption is only valid for a temperature range close to the thermoneutral zone, where the ventilation flow rate can be controlled.
The requirements of pigs (fattening and breeding) and poultry (broilers, laying hens, turkeys) for their thermal environment depend on the age and physiological stage of the animals. The younger the animals, the higher the target temperature. For livestock in temperate climate zones this means that these animals have to be kept in warm confinement houses (Gillespie and Flanders, 2009). A mechanical ventilation system is an essential part of a warm confinement building (Integrated Pollution Prevention and Control (IPPC), 2003). Such a livestock building is one that is closed,
insulated and operated in a way that keeps inside temperatures higher than, and independent of, outside temperatures during winter months. During summertime such confined housing systems can only be ventilated with a maximum ventilation rate to reduce the exceedance of the indoor temperature over the outside temperature to a certain extent of about 2 to 4 K. This means that the indoor climate can be controlled only marginally.
The indoor climate in confined livestock systems is a result of the interaction between the animals, which releases sensible and latent (water vapour) heat, the insulation of the building to capture the sensible heat, and the ventilation system. The ventilation rate is mostly controlled by the indoor temperature. The ventilation system is the most effective link to the outside, but inevitably differences will occur between climatic conditions outside and inside livestock buildings. This means that the outside meteorological situation alone cannot be used to evaluate the thermal environment of the animals. The modified indoor climate is then the relevant environment for the farm animals.
The empirical investigation is planned for two areas in Austria with a high density of animal husbandry and different climatic conditions, namely the Northern Alpine Foreland in the provinces Upper Austria/Lower Austria and South-Eastern Styria. These two regions cover more than 90% of all pigs in Austria and about two thirds of poultry (Statistik Austria, 2013).
For these two regions a reference scenario will be compiled on the basis of representative observational sites, available for the time period 1981-2010 with a time resolution of one hour. The future scenario will be generated for 2036–2065. This time period was selected according to the life expectancy of livestock housings in the range of about 30 to 50 years.
The simulation of the indoor climate (thermal parameters and air quality) for the confined livestock houses for poultry and pigs will be driven by the meteorological parameters, using the reference (1981-2010) and future (2036-2065) datasets. The system parameters for a certain livestock house will be the same for both of the two datasets, called Business-as-Usual. These model parameters depict a typical confined livestock building with a mechanical ventilation system as it is used for different livestock keeping systems (broilers, laying hens, turkeys, and various pig keeping systems). The simulated parameters of the indoor climate will be analysed and compared for the two datasets, taking into account animal welfare, health, performance, the environmental impacts, and the resulting economic consequences. It results in an assessment of the potential impact of climate change on typical confined pig and poultry buildings.
In a next step the husbandry conditions will be adapted to reduce unwanted effects of the climate change scenarios like evaporative cooling and reduction of animal density. The resulting modification of the simulation reveals the effectiveness of adaptation measures (i.e. adaptive capacity), which sums up to livestock and farm vulnerability (e.g. Klein et al., 2014). Even if some of the adaptation measures are well known especially in hot climate regions such as in parts of the US, it has to be evaluated whether they will be appropriate for Austrian farmers due do different farm structure, markets, production regulations or climate change impacts. The evaluation will include the direct bio-physical effects on animals and the environment as well as their economic implications, i.e. impacts on production costs and revenues.