COMPARATIVE STUDIES OF METHODS OF PROCESSING PATHOGEN-FREE POULTRY MANURE
Four local methods of processing poultry droppings for fish-cum-poultry culture system were evaluated to identify methods with pathogen-free poultry droppings that will be most suitable for fish culture as against the use of raw poultry droppings. Steam-heating, cooked and oven-dried, sun dried and roasted dried methods were employed to process poultry droppings for fish culture. One gram of raw and of each processed droppings were prepared separately by 10 fold serial dilution with 1litre distilled water. Bacteria counts were determined using the spread plate count on nutrient agar in triplicates after incubation at 280C for 18 h. The sun-dried had E. coli and unidentified aerobic spores of fungi while roasted dried droppings had only E. coli. The raw poultry droppings had significantly (P<0.05) higher microbial counts than the processed droppings. Laboratory analysis shows that bacteria and fungi were the dominant contaminants of raw poultry droppings. Micro-organisms isolated and identified in the raw poultry droppings were Pseudomonas, Escherichia coli, Flavobacterium, Streptomycetes, Streptococci, aerobic spores and unidentified flagellated protozoan. Microbial counts of the sun-dried and roasted dried poultry droppings were not significant (P>0.05) different. Likewise microbial counts of steam-heated and cooked oven-dried droppings were not significant at P>0.05.
Poultry population is rising every year leaving large amount of poultry refuse. The poultry population in India is 489 million and the manure availability is estimated to be 12.1 million tones (Livestock Census, 2003), while in Nigeria, about 935.5 metric tones of manure is produced annually. The poultry population is not spread throughout, but is concentrated in some pockets only. Normally, the manure is stored in most of the farms before disposal, at least for a period of one month and this leads to loss of nearly 40% nitrogen (N) which reduces the value of the manure.