Comparison of models for the relationship between respiration rate or rectal temperature and increased heat load in farm animals

Heat stress is an increasing challenge for production animals, particularly in warmer regions of the world. The aim of this study was to compare the fit of three different relationships when modelling respiration rate (RR) and rectal temperature (RT) in animals exposed to increased load. Data from three published studies on finishing pigs, gestating sows and dairy cows were analysed. RR and RT are characterized by being unaffected by increased heat load as long as it is kept below a certain level, and in warmer conditions they increase with increased heat load. As an expression of heat load either the air temperature or the ET (Effective Temperature) was used. The ET unites the effect of air temperature, air humidity and velocity on the animal perception of increased heat load. The relationship between RR and RT and the temperature or the ET was analysed by multiple change point regression and the cubic relationships were modelled. In general, the models provided better fits for RR compared to RT. Relationships with an unaffected piece followed by a quadratic relationship and the cubic relationships performed nearly equally well. Using ET resulted in better correlations than using temperature alone for gestating sows and dairy cows.

Development of a new production system for weaned and growing pigs

The design of modem housing systems for farm animals calls for cooperation between scientists within different disciplines. This article describes the design of a new production system for weaned and growing pigs, as well as the analyses and working processes behind its development. The aim of the study was to develop an economically competitive system that also provided better welfare for the animals and a healthier environment for the workers. Analyses were carried out with emphasis on behavioral needs and building design and economy. The resulting system, the "safari system," consists of a number of straw flow pens of increasing size. Pigs are moved to larger and larger pens each week until slaughter. The main advantage is that pigs are not mixed during the growth period and that they are given more space, especially toward the end of the growth period when their space demand is high. Furthermore, the provision of straw for comfort and exploration and of wallow basins for cooling in the pens for the larger pigs were considered significant welfare improvements. An analysis revealed that the safari system would be economically competitive in comparison to traditional intensive systems.