What are the technical methods for raising chickens with fly maggots?

1. Living habits of flies

At a temperature of 20-30, the pupa develops for 5 days, changing from soft to hard, and from cream yellow, light brown, and dark brown to black, and finally the adult fly breaks out of the shell from the front end of the pupa. The newly emerged adult fly cannot fly; after 1 hour, it spreads its wings and begins to eat and drink. Adult flies are lively and active during the day, and rest motionless at night. After 3 days they reach sexual maturity, and males and females begin to mate and lay eggs. From 1 to 8 days of age is the peak egg-laying period, and by 25 days of age they basically lose the ability to lay eggs. Fly eggs hatch into maggots in half a day to 1 day, and generally become pupae on the 5th day. One generation of flies is about 28 days. Temperature and the nutrients in the maggot feed have a great influence on the growth and development of maggots. Generally, within a room temperature range of 20-30°C, the higher the temperature and the richer the nutrients, the faster the maggots grow and develop, and the larger the pupae they become.

2. 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 renovated. Glass and screen windows are installed on the doors and windows to help regulate temperature, and fans are installed on the walls to regulate the air. Heating equipment should be provided in the house to keep the temperature at 20-23°C in winter, and the relative humidity in the house should be kept at 60%-70%. Black cloth curtains are installed in the passageways to prevent breeder flies from escaping. Rearing racks are set up in the house, divided into 3 tiers: upper, middle, and lower. The rearing racks are made of iron or wood. On each tier are placed fly cages made of nylon gauze netting, with cages 100 cm long and 80 cm high. The breeder flies are kept inside the cages for rearing, with 12,000 breeder flies per cage. Each cage is fitted with a cloth sleeve for 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 feed basins with gauze pads on the surface, allowing the adult flies to stand on the gauze and feed. The 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 cage for the breeder flies to lay eggs. Eggs are collected once a day from the breeder fly cages 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 egg collection time should be appropriate. Each batch of breeder flies is culled after 15-20 days of rearing, killed with hot water or steam, dried and ground into powder as livestock and poultry feed, and then a new batch is replaced. While producing fly maggots, the fly maggots pupate. There are 2 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 the maggots have been reared for about 5-6 days and turn yellow, to take out the fly maggots and prompt them to pupate.

3. Cultivation of fly maggots

For fly maggot breeding, 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 racks with plastic trays can be used for maggot rearing. A plastic tray with a diameter of 50 cm can rear 1.5 kg of maggots, requiring only 3 kg of wheat bran, and they can be collected and used after 3-4 days of rearing. There are many sources of maggot rearing material, and the cost of different maggot materials varies, so they can be reasonably selected. Wheat bran has relatively high nutritional content and is also slightly more expensive, and is generally used to breed breeder flies, while low-priced distillers grains, soybean residue, 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 fly maggots. When using it, water should be added and mixed evenly, with the degree of dryness and wetness being that water comes out when squeezed by hand and it breaks apart when touched (water content 60%-65%). If semi-dry and wet materials such as distillers grains and soybean residue are used, they can be cultivated without adding water. The specific maggot rearing method is to pour the laid eggs and wheat bran material into a tray, add maggot materials such as distillers grains, soybean residue, or wheat bran, and mix slightly evenly. Note that 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 is based on the standard that the fermentation temperature within the maggot material is not higher than 40°C and not lower than 20°C, 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. Human and livestock manure needs to be treated to kill bacteria and parasites before use. As for the ratio of material to maggots, taking chicken manure as an example, generally 3.5-4.0 kg produces 0.5 kg of fresh maggots. Regardless of which raw material is used for rearing maggots, the dryness and wetness of the maggot material should be controlled at 60%-65%.

4. Collection of fly maggots

Collection is carried out by taking advantage of the fact that fly maggots are afraid of light. Use a manure rake to continuously stir the surface layer of the drinking water in the maggot rearing pool, and the fly maggots will burrow inward. Remove the surface layer of manure material. Repeat this method many times, and finally a small amount of manure material and fly maggots remain. The separated fly maggots can be directly used to feed livestock and poultry after washing, or dried at 200-250°C for 15-20 minutes for processing and storage for later use.

For raising chickens with fly maggots, local native chicken breeds can be directly selected. They generally have relatively strong stress resistance and disease resistance, and whether raised in sheds or released or confined in orchards and fields, a relatively high survival rate can be obtained. When selecting chicks, choose male chicks that are all black or of other colors according to market demand, so as to ensure better sales and prices.

After fly maggots are taken out from the collected maggots and pupae, they can be rinsed with clean water and fed directly to chickens, and the amount can account for 30% of the total feed. If the fly maggots are scalded to death with boiling water before feeding, the mixing amount can account for 40%. Because fly maggots have a relatively high protein content, other feeds should mainly be energy feeds such as cornmeal and wheat bran, and there is no need to add protein feeds such as soybean meal and fish meal.