[Ethically chosen studies with early-weaned piglets during their raising in pens with different applications of straw. 1. The effects of different applications of straw and different floor conditions in areas of uniform size].
In extension of earlier experiments in housing systems with perforated floors, utilization rates of solid floor with litter, straw in a rack and deep litter, as well as the behaviour and physical condition, especially of claws, were investigated. Each pen had an area of 0.45 m2/piglet. In further experiments the influences of race (DL instead of DL x Piétrain), kind of rearing (without straw instead of rearing with straw), lowering temperature and the effect of a preferred perforated floor in comparison with solid floor were investigated. Deep litter was preferred for activity and lying behaviour only in the case of low temperature (14-18 degrees C) whereas solid floor with litter was preferred in the case of higher temperature (19-25 degrees C). The perforated floor was equivalent to solid floor on the condition that the area dimension was sufficient, temperature 3 degrees C higher than in the other experiments and straw in a rack was offered. However, the utilization rates of solid floor increased in the case of lowering temperature by 4 degrees C. There was no significant influences of the different race or kind of rearing. In the experiments there were significant signs of a more harmonious condition of the animals and a shorter, respectively no period where the animals had to adapt to the housing conditions. These findings were in contrast to those of earlier investigations. The possibility of acting with straw led to an undisturbed circadian rhythm and to a higher rate of standing within the total activity which was as high as in earlier studies. Further social companions and environmental objects lost attractiveness.(ABSTRACT TRUNCATED AT 250 WORDS)