The effects of air temperature and relative humidity in climatic chamber on the growth and carcass composition of swine from weaning to slaughter

Abstract

The performance in terms of rate of gain, food conversion efficiency and carcass quality measurements was studied in pigs held under the artificial conditions of a climatic chamber at constant air temperature 81,7°F (27,6°C). At weaning the male animals were paired for breed, weights and allocated to the two treatments and then were housed in individual yards. Feeding was carried out twice daily, in individual feeding crates and any feed refused was weighed and recorded. Water was constantly available and recorded as well. The live weight of the pigs was registered once a fortnight and the rations adjusted accordingly. The experimental period lasted 107 days. After reaching about 180 lb (82 kg) of body weight, the pigs were weighed and starved during 24 hours and slaughtered the next morning. After weighing the hot carcasses, they were cooled at 2°C until next morning and then re-weighed and measured. The killing out percentages were calculated on the basis of live weight and the hot carcass weight. The results of the experiment are described separately according to: a) rate of gain, food and water intake and conversion efficiency; b) live weight and carcasses measurements related to the air temperature and relative humidity; c) effects of the air temperature and humidity on the body temperature, respiratory and pulse rates. Analysis of variance was carried out for live weight initial and final, rate of gain, food intake and conversion efficiency and no significant differences were encountered between treatments — climatic chamber and environment — except the significant higher water intake observed in the lot held in climatic room. It is apparent as well that differences between treatments were not significant in length, loin fat at three points and “eye” muscle dimensions. Significant positive correlations were demonstrated between daily gain and body weight until 110 lb (50 kg) in both treatments, while at higher weights it continued positive but lacked statistical significance. In the light of the findings here encountered it was concluded that the constant air temperature of 81,7°F ± 0,07 (27,6°C) and relative humidity of 72,5 ± 0,60 per cent held at the climatic room, were not capable to exert influence upon the performance of pigs.