Volatile fatty acids in anaerobically stored piggery wastes

Volatile fatty acids (VFA) were estimated in 30 samples of farm slurries. The total concentration of VFA in these samples ranged from 4.0 to 27.6 g/litre (aver age 11.8 g/litre with standard deviation of 5.6 g/litre). From laboratory experi ments it was derived that VFA are produced from faeces whilst only nonsignificant amounts originate from urine. During 70 days incubation of a mixture of freshly voided faeces and urine, 43 % of the protein and 24 % of the plant-fibre residues were degraded. The resulting products were predominately VFA and carbon dioxide.