STUDIES OF THE EFFECTS OF DIFFERENT VENTI LATION SYSTEMS ON THE ECONOMICS OF FATTENING PIGS - RESEARCH RESULTS

The study was conducted on a commercial fattening pig herd. Two identi cal units housing 150 growing pigs weighing between 7.5 and 29 kg were used. The animals were kept in groups of 25 on fully slatted concrete floors and fed ad lib by automatic feeders. The only difference betwe en the two units was the system for the incoming air distribution. One unit had a porous ceiling as an air inlet and the other was fitted wi th an automatically controlled inlet baffle. Two growing periods were observed, one during the summer of 1991 and the other during the winte r of 1991/1992. The effect of the two systems on the health and growth of the pigs together with the energy consumption for heating were mea sured. During both periods mortality rates were negligible and no trea tments were necessary. During the summer period no difference between the systems was observed. The unit with the porous ceiling had a more stable air temperature. This provided a more favourable working enviro nment for the personnel, but did not affect the health of the pigs or the efficiency. During the winter the porous ceiling unit had an impro ved heat balance with 1260 kWh less energy within the first four weeks and a better air quality. These conditions resulted in a greater dail y liveweight gain of 14 g, but this was not statistically significant. The manager and working staff were convinced that the porous ceiling was beneficial and a beneficial economic investment.