Effects of broiler litter volatiles and ammonia on fungal spore germination.

The effects of broiler litter volatiles on spore germination of 12 fungal species were determined. The volatiles inhibited spore germination of all species except Scopulariopsis brevicaulis. The inhibitory effect was fungistatic. The inhibitory volatile substances in litter were higher in built-up litter than in freshly used litter and were soluble in an acid solution. Ammonia was identified by infrared analysis as a fungal inhibitory substance in litter. The effect of various concentrations of ammonia produced from ammonium chloride (NH4Cl) was studied, and it was determined that concentrations of ammonia below 150 micrograms/g dry weight of litter were fungistatic for most species. At higher concentrations, ammonia was fungitoxic, with the exception of S. brevicaulis whose spore germination was not inhibited at this high concentration. Fungitoxic levels of ammonia were not found in the litter samples, but broiler house conditions necessary to produce fungitoxic levels are discussed.