STUDIES ON LOAD OF IMMISSION OF FATTENING PIGS AND THE ENVIRONMENT OUTSIDE OF PIG - FATTENING FARMS CAUSED BY LUNG PASSING DUST PARTICLES, PIGHOUSE SPECIFIC AIRBORNE BACTERIA AND AMMONIA

According for their topographic and isolated locations (no built-up ar ea or trees downwind) 13 fattening pig pens with an average stocking r ate of 737 (360-2500) have been investigated for burden by immission o f animals and the environment outside the stables up to a distance of 100m downwind of the source. These studies have been carried out betwe en June 1988 and April 1989 in monthly intervals. The investigated par ameters have been: dust of particle size < 5 mu m, stable specific bac teria, ammonia and symptoms of animals respiratory diseases. In the st alls could be shown an significant seasonal influence on bacteria, lun g passing dust content and ammonia concentration with a maximum during December/January (1,1 x 10(6) CFU/m(3); 0,26 mg/m(3); 27 ppm) and min imum during June/July (5,7 x 10(5) CFU/m(3); 0,075 mg/m(3); 11 ppm). I n the environment outside the pigsties a significant seasonal influenc e could be found only for the stable specific bacteria up to the dista nce of 100m of the source of emission, showing a maximum during fall a nd winter 11,7 x 10(3) CFU/m(3)) and minimal concentration during spri ng and summer (9,3 x 10(2) CFU/m(3)). Due to emission of spent air a h igh significant reduction of the stable specific bacteria and lung pas sing dust concentration could be established outside the stables withi n a distance of 10 m. The content of stable specific bacteria come to 0,2% (1941 CFU/m(3)) compared with the amount measured at the air outl et of the spent air shaft. At this distance the lung passing dust conc entration has been reduced to 11% (0,016 mg/m(3)) of the concentration at the emission source. In comparison to the examined ,,neutral air'' upwind, the content of lung passing dust downwind has not been height hened significantly at any measuring point or time of the year, wherea s the content of stable specific bacteria downwind was significantly h igher up to a distance of 50 m (p less than or equal to 0.01). The sta ble specific bacteria that were isolated from the air outside the pigs ties, mostly gram positive cocci, had in part a strong resistance agai nst Erythromycin, Penicillin, Tetracyclin and Ampicillin. The fact tha t in all investigated farms irritations or dieseases of the animals re spiratory tract in different degrees of intesity could be determined s hows the urgency to minimize the burden by optimizing the hygienic sit uation inside the stalls. This means especially the colder period of t he year, because a high frequency of transgression of the ammonia thre shold value according to German regulations for pig housing could be f ound in this time.