[Hygienic aspects of the microclimate in intensive management of rabbits]

In a four-row cowshed adapted for rabbit housing, air temperatures and humidity were recorded ambulantly and instrumentally, air flow rate, cooling variable, gas content in the air, microbial contamination of air and dust deposition were determined ambulantly in the years 1991-1992 and in January to April 1993. The values of ambulant measurings show that at the outside temperature -0.5 degrees C to -5.0 degrees C the microclimate quality decreases particularly with respect to the drop of air temperature in the cowshed below 10.0 degrees C, to the increase in cooling variable up to the value 53.17 mW/cm2 and to the increase in NH3 and CO2 content to 50 ppm and/or 0.45 vol.% in absolute maximum values. In these circumstances, the average determined values of both gases are higher than the standard prescription. At outside temperatures above 27.0 degrees C the average relative air humidity in the cowshed made 69.20% for the average temperature of 25.0 degrees C. To avoid the water vapor tension exceeding the limit in the cowshed air above the value 14.1 mm Hg, when sultry atmosphere sets in, the average relative air humidity should be maximally 59.0%. Hence the cowshed was found to be insufficiently ventilated at high outside temperatures above 27.0 degrees C, and it is recommended to increase the ventilator performance and at the same time to reduce water evaporation from catchpit surfaces when urine output of rabbits is excessive as a result of the increased water intake. Temperature and air humidity readings confirmed the need of heating source installation when the outside temperatures drop below 0.0 degrees C. Evaluation of air microbial contamination showed high counts of molds and particularly of micrococci in comparison with the ambience of a cage facility for piglet raising at a repopulation station with strict hygienic regime. Microbial picture of dust deposition was positively influenced by longitudinal aerosol disinfection of the air in the cowshed.