Impact of global climate change on the health,welfare and productivity of intensively housed livestock

Major scientific studies have shown that global warming(i.e.increasing average temperature of the Earth)is now a reality.The aims of this paper are to broadly review the underlining causes of global warming,the general effects of global warming on social and environmental systems and the specific effects of resulting from global warming phenomena severe fluctuations in weather patterns,particularly heat waves on livestock health,welfare and productivity.Finally this article aims to summarise some common sense climate control methods and more importantly to highlight the required future research and development(R&D)work that is necessary to achieve a new level of building environment control capability,and thus ensure that the intensive livestock industries will be able to cope with the changed external climate.With the increasing temperatures on a global scale,the most direct effect of the high temperature on the animals is heat stress,which has been proven to have a variety of negative effects on animal health,welfare and productivity.Different potential measures could be taken in future to alleviate the increased heat stress.Some of these measures are mere adaptations or improvements of current engineering solutions.However,facing the complex challenges of global warming and particularly resulting from it the rapid increase of the number of consecutive days with significantly higher than average temperatures will probably require novel solutions,including new designs based on solid engineering judgment,development of new engineering standards and codes to guide designs,the exploration of new and superior building materials,the need for better energy management,and the development of substantially more“intelligent”control systems that will balance changing exterior disturbances,interior building loads and demands to the biological needs of the occupants of the structures.

Applying multi-criteria analysis to select the most appropriate broiler rearing environment

The present study aimed to assess the most appropriate rearing system for broiler housing in tropical regions using the Analytical Hierarchy Process(AHP).The research was done using data sampling from a field study carried out in eight mechanically-ventilated commercial broiler houses.Four had positive ventilation(open-sided conventional system),and the other four had negative pressure systems,which were named according to the curtains color and light management(blue-house with blue curtains,and dark-house with black side curtains).The data from the field research(rearing dry-bulb temperature and relative humidity;ammonia and carbon dioxide concentrations;energy use;litter type and quality;and broiler performance)were organized,and the multi-criteria analysis AHP was applied.In the process,the decision-maker must define the problem and chose the criteria to evaluate the alternatives to make a suitable decision.The alternative selected needs to be according to the stakeholders’expectations.The alternatives consisted of houses using three ventilation systems(conventional,blue-house,and dark-house).The different chosen criteria were the thermal and aerial environment,broiler productivity,energy consumption,and litter quality.We selected data collected from the field experiment and from current literature to subsidize the selection of the criteria.The computation was done using field data results,knowledge from existing literature,and the expertise of three specialists.For the first time,the AHP technique is applied to select the most suitable broiler housing,considering the complex variables involved in the process.Results indicated the conventional system as the most appropriate alternative.Results of the conventional system showed the highest scores on most criteria in the pairwise comparison.Which considered broiler performance,gasses concentration,and electricity cost,providing natural ventilation open-sided conventional house as the most appropriate rearing system for broiler production in tropical countries.