Basic knowledge of feeding and management that must be mastered for maggot farming

Rearing and breeding of breeder flies: Breeder flies should be kept in a fly house. The size of the breeder fly house can be built according to need, or an old house can be converted. Glass and screens should be installed on doors and windows to help regulate temperature, and fans should be installed on the walls to regulate air. Heating equipment should preferably be provided in the house so that the winter temperature is maintained at 20-23°C, and the relative humidity in the house is maintained at 60%-70%. Black cloth curtains should be installed in the passageways to prevent the breeder flies from escaping. Rearing racks should be set up in the house, divided into upper, middle and lower tiers. The rearing racks are made of iron or wood. On each tier, fly cages made of nylon mesh are placed. The cages are 100 cm long and 80 cm high. The breeder flies are kept inside the cages for rearing. Each cage holds 12,000 breeder flies. Each cage is fitted with a cloth sleeve to facilitate adding feed, adding water and collecting eggs. 12,000 adult flies are fed 20 grams of milk powder per day. The feed is placed in a feed basin with a gauze pad on the surface, allowing the adult flies to stand on the gauze and feed. Feed and water are changed once a day. Gauze is placed in the water basin, and wet wheat bran is placed in the egg-laying dish for the breeder flies to lay eggs. Eggs are collected from the breeder fly cages once a day and sent to the maggot house for maggot rearing. Breeder flies lay the most eggs from 8 a.m. to 3 p.m. each day, so the timing of egg collection should be appropriate. Each batch of breeder flies is kept for 15-20 days and then culled. They are killed with hot water or steam, dried and ground into powder as livestock and poultry feed, and then a new batch is introduced.

While producing maggots, the maggots pupate. There are two methods for obtaining new breeder flies: one is to let them pupate naturally and wash out the fly pupae with water; the other is, when they have been reared for about 5-6 days and turn yellow, to take out the maggots and place them in dry powder to promote pupation.

 Culture of maggots: For maggot farming, brick-built maggot rearing pools with a side height of 20 cm and an area of 1-3 sq m can be used, or bamboo and wood can be used to build racks with plastic trays for maggot rearing. A plastic tray with a diameter of 50 cm can rear 1.5 kg of maggots and requires only 3 kg of wheat bran. After 3-4 days of rearing, they can be collected for use. There are many sources of maggot rearing material, and the cost of different maggot materials varies, so a reasonable choice can be made. Wheat bran has relatively high nutritional content and is also slightly more expensive. It is generally used to breed breeder maggots. Low-priced distiller's grains, okara and the like can be used as material for commercial maggots. If wheat bran is used as maggot material, generally 1 kg of wheat bran can produce 0.5 kg of maggots. When using it, water must be added and mixed evenly. The suitable degree of dryness and wetness is that water comes out when squeezed by hand and the material breaks apart when touched (water content 60%-65%). If semi-dry and wet materials such as distiller's grains or okara are used, they can be cultured without adding water. Specific maggot rearing method: Pour the eggs and wheat bran material into a tray, add maggot materials such as distiller's grains, okara or wheat bran, and mix briefly until even. Note that the fly eggs should not be exposed on the surface of the maggot material, so as to avoid loss of water and loss of vitality. The thickness of the maggot material should be based on the standard that the fermentation temperature within the maggot material is not higher than 40°C and not lower than 20°C. It is generally 5-10 cm. In summer, when the temperature is relatively high, the maggot material should be appropriately thinner; conversely, in winter, when the temperature is relatively low, the maggot material can be appropriately thicker. If human or livestock manure is used, it should be used after killing bacteria and parasites. For the ratio of material to maggots, taking chicken manure as an example, generally 3.5-4 kg produces 0.5 kg of fresh maggots. No matter which raw material is used for maggot rearing, the dryness and wetness of the maggot material should be controlled at 60%-65%.