CHARACTERIZATION OF ODOROUS COMPOUNDS AND EMISSIONS FROM SLURRIES PRODUCED FROM WEANER PIGS FED DRY FEED AND LIQUID DIETS

Changes in odorous emissions were recorded from slurries produced by w eaner pigs fed dry feed and feed with water added in the respective ra tios of 3:1 and 4:1. Slurries were placed in an environmentally contro lled emissions chamber, periodic air sampling was performed to determi ne the olfactometric response as odour concentration, and the air was analysed to identify volatile organic compounds present. Distinctive o dours were produced by each slurry. However, four major groups of odor ants were identified as sulphides, volatile fatty acids, phenols and i ndoles. The odour concentration from the slurry of the 4:1 diet was si gnificantly less (P < 0.05) than the odour concentration from the dry feed and 3 :1 slurry samples. Decay of the sulphide component of the o dours was investigated and the role of methanogenesis in reducing odou r production is discussed. While monitoring the emissions in the chamb er the slurry odorant concentrations increased by up to 50 ppm h(-1).