A two-stage composting experiment was performed to utilize pig manure for producing maggots as feed
supplement and organic fertilizer. Seven-day composting of 1.8 ton fresh manure inoculated with 9 kg
mixture of housefly neonates and wheat bran produced 193 kg aging maggots, followed by 12 week composting
to maturity. Reaching the thermophilic phase and final maturity faster was characteristic of the
maggot-treated compost compared with the same-size natural compost. Upon the transit of the maggottreated
compost to the second stage, the composting temperature maintained around 55 C for 9 days
and the moisture decreased to 40%. Moreover, higher pH, faster detoxification and different activity patterns
for some microbial enzymes were observed. There was a strong material loss (35% water-soluble
carbon and 16% total nitrogen) caused by the maggot culture in the first stage. Our results highlight a
higher economic value of pig manure achieved through the two-stage composting without bulking
agents.