A FARM SCALE STUDY ON THE USE OF DE-ODORASE(R) FOR REDUCING ODOR AND AMMONIA EMISSIONS FROM INTENSIVE FATTENING PIGGERIES

An experiment was mounted at a large fattening piggery in Slovenia, du ring which different groups each of 600 weaned pigs were housed and gr own in different fattening roams for 60 days (from age 24 days to age 84 days). All rooms were mechanically ventilated and had fully-slatted floors with slurry channels beneath. De-Odorase(R)dagger+ was added t o the diet of the treated groups of pigs at the rates recommended by t he suppliers, e.g. for grower feed, 65 g/t. De-Odorase(R) was also add ed daily (3.2 g suspended in 10 l of water) to the upstream ends of th e slurry channels. Once a week, the ammonia concentration in the air i nside each fattening room was measured at each of four positions, usin g Drager tubes, and the ventilation rate was computed from the cross-s ectional area of each fan outlet and the average velocity of the air e merging from each. Also, air samples were taken from immediately outsi de three of the fans sewing each room, and their odour concentrations were measured by olfactometry. Hence, weekly values of emission rates of both ammonia and odour could be calculated. Ammonia concentration w as significantly lower (P = 0.001) in the De-Odorase(R)-treated buildi ngs than in the control buildings. The average reduction in ammonia co ncentration over a 7 week period was 26%. Ammonia emission rate was al so reduced by 26% through the use of the additive. This reduction was significant at P = 0.048. Neither odour concentration nor odour emissi on rate was significantly reduced through the use of the additive. The additive did not significantly influence the rate of live-weight gain by the pigs.