What are the efficient technical methods for feeding fly maggots to chickens?
The larvae bred by the housefly are called fly maggots, which are a high-quality animal protein feed. The nutritional composition of fly maggots is similar to that of high-quality fishmeal: the dry product contains 59%-65% crude protein, 11%-13% crude fat, 0.3%-0.7% calcium, and 1.7%-2.6% phosphorus. Feeding laying hens with 10% fly maggot meal increases the egg production rate by 20% compared with laying hens fed an equal amount of fishmeal, and improves the feed conversion ratio by more than 15%. Fly maggot farming is divided into two stages: breeding stock flies and rearing fly maggots. Raising stock flies is for obtaining large numbers of fly eggs to propagate fly maggots. Eggs laid by chickens raised on fly maggots are rich in multiple vitamins and carotenoids; the fat content in the eggs does not exceed 3% for ordinary packing of maggot eggs, the protein content exceeds 12%, and they contain multiple amino acids essential to the human body, as well as minerals such as sodium, potassium, and calcium.
I. Raising Stock Flies
1. Making fly cages. Stock flies have flying ability, so they must be kept in cages. Use wooden strips or 6.5 mm diameter steel bars to make a rectangular frame of 65 cm × 80 cm × 90 cm, cover the outside of the frame with plastic window screening or fine-mesh copper wire netting, and install a gauze glove on one side of the cage net for feeding and handling. Each fly cage is equipped with 1 feed basin and 1 water dispenser. One cage can hold 40,000-50,000 adult flies.
2. Preparing feed. Feed stock flies with 5% syrup and milk powder; or grind fresh maggots, take 95 g of maggot slurry and 5 g of beer yeast, add 155 mL of cold boiled water, mix well, and feed. When first raising them, you can use rotten eggs and place them in a small white porcelain jar for feeding. The feed and water are replaced once a day.
3. Breeding stock flies. For the source of stock flies, you can wash fly pupae clean and put them into the stock fly cage, and when 5% have emerged, begin providing food and water. Three days after the stock flies begin mating, place an egg-laying tray in the cage. Fill the tray to 2/3 of its height with attractant material. The attractant material is made by mixing wheat bran, chicken feed, or pig feed with an appropriate amount of dilute ammonia water or ammonium carbonate water. Collect eggs 1-2 times a day, and pour the eggs together with the attractant material into the larval culture room for culturing.
4. Controlling temperature and humidity. The temperature of the stock fly room should be controlled at 24°C-30°C, and the relative air humidity should be controlled at 50%-70%.
II. Rearing Fly Maggots
1. Rearing equipment. For small-scale rearing, jars, basins, etc. can be used; for large-scale rearing, pond culture is suitable. Use bricks to build a pond on the ground measuring 1.2 × 0.8 × 0.4 m, and plaster the pond walls with cement. Cover the pond opening with a wooden frame covered with fine copper wire or screen silk as a lid.
2. Fly maggot culturing. The culture material can be livestock and poultry manure, or it can be prepared from distillers' grains, sugar residue, tofu residue, slaughterhouse offal, etc. The culture material has a water content of 65%-70% and a pH value of 6.5-7. Pour 35-40 kg of culture material into each square meter of the rearing pond, with a thickness of 4-5 cm, and inoculate 200,000-250,000 fly eggs per square meter, weighing 20-25 g. When inoculating, the fly eggs can be evenly scattered on the surface of the material. Keep the culture room dark, and control the culture material temperature at 25°C-35°C. After several days of culturing, the culture material temperature drops and its volume shrinks. At this time, fresh material should be added according to the number and growth of the fly maggots. At a temperature of 24°C-30°C, after 4-5 days and nights, the individual weight of the fly maggots can reach 20-25 mg. The fly maggots tend to mature; except for those retained as breeding stock to let them pupate, the remaining fly maggots can be separated and harvested by the following methods
3. Separation and harvesting. ① Chicken feeding separation. Scatter the maggots and the remaining culture material into the chicken pen, let the chickens eat the fresh maggots, and then clean out the culture material completely. ② Strong light separation. Because fly maggots are afraid of strong light, strong light can be used for irradiation; after they move down from the surface of the culture material, peel off the surface culture material layer by layer, and a large number of fly maggots can be obtained from the bottom layer. ③ Water separation method. Pour the maggots and the remaining culture material together into a water vat; after stirring, wait for the maggots to float on the water surface, and scoop them out with a sieve.
4. Scientific feeding. When fly maggots are used as feed, poultry are mostly fed fresh maggots directly (livestock are mostly fed dry powder, that is, the maggots are scalded to death, sun-dried, ground into powder, and added to compound feed for feeding).