Detailed Explanation of Key Points on Hatching Techniques for Silkie Chicken Breeding Eggs

I. Selection of Hatching Equipment

Nowadays, hatching equipment has become increasingly sophisticated, basically achieving automation and microcomputer control. Traditional hatching methods are basically no longer used, and adopting modern hatching equipment not only saves manpower but also achieves a higher hatching rate.

There are currently many hatching equipment manufacturers in China. When purchasing equipment, be sure to buy from manufacturers with strength, reputation, and quality assurance. If the equipment is poor, it brings not only the problem of the equipment's value to farmers but also directly affects the success rate of future hatching (since the company has a long-term incubator partner, customers can also contact the company directly when they need to purchase). When purchasing equipment, the general requirements are: 1) timed automatic egg-turning function 2) automatic temperature control function 3) automatic humidity control function 4) automatic ventilation function 5) automatic ultra-high and low temperature alarm and activation of cooling and heating functions 6) the machine's internal components can withstand high-temperature and high-humidity operation, and have the characteristics of long continuous service life 7) having emergency power supply equipment against power outages

II. Debugging of Hatching Equipment

After the incubator is purchased and assembled, it must be debugged. The scope and methods of debugging include: 1) whether the operation of each component is normal (egg-turning, heating, humidifying, ventilation, alarm, etc.). 2) using multiple thermometers to calibrate the temperature sensor. 3) using a hygrometer to calibrate the humidity sensor. 4) using multiple thermometers placed at various positions in the machine cabinet to measure temperature, to see whether the temperature at each position of the cabinet differs greatly, and to measure multiple times at the same position. Generally, the temperature difference between locations must not differ by 0.5°C. If it exceeds this number, carefully check and find the cause, and resolve and adjust it. After the incubator is properly debugged, it must be trial-run for two days, and then measured again to see whether it operates normally.

III. Selection of Breeding Eggs

Breeding eggs placed in incubation should come from healthy chicken flocks. For laying hen flocks, full-price compound feed should be used to ensure that the protein, vitamins, minerals, and other contents in the feed can meet the production needs of the flock, and a reasonable male-to-female ratio is also required. Because Silkie chickens have a large amount of activity and small naturally mating groups, the general male-to-female ratio is 1:4-5.

1. Morphological characteristics of Silkie eggs The appearance of Silkie eggs is similar to ordinary domestic chicken eggs, white in color, with an average egg weight of 38 grams, slightly smaller than ordinary domestic chicken eggs.

2. Selection of breeding eggs (1) Breeding eggs must be fresh in quality; eggs laid within ten days are best, with a higher hatching rate, and the chicks hatched are more robust. (2) The shape and size of breeding eggs must be appropriate; eggs that are too large, too small, too round, or too long are not suitable for hatching. (3) The egg structure must be normal; thin-shelled eggs, "sand-skinned eggs," and thick-shelled eggs are all unsuitable for hatching. (4) They must be clean and free of cracks; overly dirty eggs and broken eggs are often contaminated by microorganisms and are prone to spoilage and contamination of the incubator. In addition, breeding eggs should come from healthy breeding flocks with normal feeding and management.

3. Storage and transportation of breeding eggs

Breeding eggs should be stored in a cool and clean house. If stored for one week, the most suitable storage temperature is 15-18°C, and they must be protected from heat and freezing. A storage environment humidity of 70-80% is suitable. If preserving the good quality of breeding eggs, the shorter the storage time, the better. After one week of storage, turn the eggs once a day. For transportation of breeding eggs, attention must be paid to complete packaging to avoid severe vibration. For long-distance transportation, special egg trays can be used, with shock-absorbing sponge pads added, placed in cardboard boxes, or a layer of sawdust can be spread in the cardboard box, one layer of eggs and one layer of sawdust, until full, so that they are not easily bumped from top, bottom, left, or right. Handle gently when loading and unloading.

IV. Disinfection of Breeding Eggs

Disinfecting breeding eggs can increase the hatching rate and reduce the disease infection rate and mortality rate of chicks after hatching. Therefore, every day after collecting a certain number of breeding eggs, they must be disinfected, and they must also be disinfected again before being placed in incubation. Methods include: 1) Disinfect with benzalkonium bromide, using the method and dosage according to the instructions. 2) Soak in 1/5000 potassium permanganate water for 3-5 minutes. 3) Use 40% formalin 28ml per cubic m and potassium permanganate 14 grams per cubic m, reacting and fumigating for 20 minutes for disinfection; this method is generally used for disinfection before breeding eggs enter storage. Regardless of which disinfection method is used, the disinfectant must be highly effective and low in toxicity, the water temperature must reach 40°C, the spray water temperature must reach 45°C, and for fumigation disinfection the environmental temperature must reach 20 to 25°C and the humidity must reach 70%-80%. When the humidity cannot be reached, 20% water can be added to the formalin.

V. Storage of Breeding Eggs

The storage of breeding eggs requires that the time be as short as possible, and the hatching rate will be higher. Generally, storage for one week will not have too great an impact on the hatching rate. The suitable storage temperature range is 7.5°C-18°C, and the humidity is 70%-80%. As the storage time lengthens, the temperature requirements for storage become lower. It should be noted that when storing breeding eggs, temperature increases and decreases must be carried out gradually. The environmental requirements for breeding egg storage are cleanliness, protection from flies, and protection from rats.

VI. Temperature Requirements for Breeding Egg Hatching

Temperature is an important condition for embryonic development. In a short time, embryos can still develop at a temperature of 32-40 degrees. In the early stage of incubation, because the embryo is small and lacks the ability to adapt to external temperature and regulate body temperature, a slightly higher temperature is needed. In the later stage of development, the embryo has initially acquired the ability to regulate body temperature, and because fat metabolism is strengthened and a large amount of physiological heat is produced, a slightly lower temperature is needed. This is the principle of applying higher temperature in the early stage, medium temperature in the middle stage, and lower temperature in the later stage. For all-in-all-out incubation, 1-7 days is the early stage, using a temperature of 38-38.5 degrees; 8-14 days is the middle stage, using a temperature of 37.5-38 degrees; 15-21 days is the later stage, using a temperature of 37-37.5 degrees. If multiple batches of breeding eggs are incubated simultaneously in the machine, 37.9 degrees can be used, and at 21 days the temperature can be appropriately increased by +0.5 degrees to facilitate the smooth hatching of the chicks.

VII. Humidity Requirements for Breeding Egg Hatching

Embryonic development has a relatively wide adaptive range for humidity, generally between 50%-70%. For 1-7 days, the early stage, the relative humidity is 60%; for 8-17 days, the middle stage, the relative humidity is 50%; for 18-21 days, the later stage, the relative humidity is 70%. In the later stage, in addition to the relatively high humidity requirement, water can be sprayed on the surface of the eggs to promote the chicks' absorption of calcium in the eggshell, which also helps the chicks hatch.

VIII. Ventilation Requirements

Ventilation is mainly to provide oxygen to the embryo and expel harmful gases from the machine. Various incubators now have ventilation equipment, so manual ventilation is generally not needed. When ventilation conflicts with temperature, the temperature requirement should be satisfied first.

IX. Egg-Turning Requirements

The main function of egg turning is to prevent the embryo from adhering to the egg membrane. The number of egg turnings is generally set to once every 1.5-2 hours.

X. Placing Breeding Eggs in Incubation

After all functions of the incubator are set, place the eggs on trays and begin incubation. When loading the trays, the eggs taken out from the egg storage room should be preheated so that the egg temperature reaches 20-25 degrees. When loading the trays, the large end of the breeding eggs should face up. After the tray is full, if there is a relatively large gap, some shredded paper can be stuffed in. Each egg tray should be numbered and have incubation records to prevent confusion when adjusting trays. Only after the temperature inside the machine has stabilized at about 38 degrees for several hours can the eggs be placed in incubation.

XI. Egg Candling

Egg candling is for checking the incubation situation and identifying infertile eggs, dead embryo eggs, and weak embryo eggs. Egg candling is divided into three times: the first candling is on the 5th day after placement in incubation. The eye spot can be seen, blood vessels occupy four-fifths of the front of the egg, and the color is bright red; this is a normal egg. If the blood vessels do not occupy four-fifths and the eye spot cannot be seen, it is a weak embryo egg. If it is turbid with blood rings or blood clots, it is a dead embryo egg. If the inside of the egg is bright and only the shadow of the yolk can be seen, it is an infertile egg. Infertile eggs, dead embryo eggs, and some poorer weak embryo eggs should be culled. The second candling is on the 10th to 11th day. If the blood vessels close together at the small end of the egg, it is a normal egg; if they do not close together, it is a weak embryo egg; if the air chamber is relatively blurry and the embryo appears as a black mass, it is a dead embryo egg. The third candling is on the 18th day. With the small end of the egg facing the light source, no bright place can be seen. If a red band about 1 mm wide is seen at the large end closely attached to the air chamber, it is a normal egg; if the band is not red, it is generally a dead embryo egg.

XII. Cooling Eggs

The main function of cooling eggs is to dissipate excess physiological heat inside the eggs and provide sufficient oxygen to the embryos, preventing overheating accidents and embryonic death from lack of oxygen. From 1 to 7 days of incubation, cooling eggs is not needed; from 8 to 12 days, cool once a day; from 13 to 17 days, cool twice a day; from 18 to 20 days, cool once every 4 to 6 hours. Cooling eggs can be combined with tray adjustment. The method is to take the eggs out of the incubator to cool. If incubation is done as a whole, the ventilation holes of the incubator can be opened for cooling. The temperature for cooling eggs should be kept at about 35 degrees egg temperature (that is, when the egg contacts the skin near the human eye, there is a warm but not cool feeling). The environmental temperature during cooling is generally about 25 degrees. Generally, incubators with good ventilation performance do not need egg cooling.

XIII. Hatching and Receiving Chicks

When eggs have been incubated for 18 to 20 days, egg turning is no longer needed. Combined with candling, live embryo eggs can be transferred to hatching trays for hatching. If there is a hatcher, they must be transferred to the hatcher for hatching. After chicks begin to hatch, chicks must be picked up once every two to four hours. When picking up chicks, wait until the down is dry. The cardboard boxes or chick-receiving baskets holding chicks should not be too large. In hot weather, place fewer; in cold weather, place more. After chicks are picked out, they should be promptly transferred to a warmth-preserving room or brooding house. After chicks hatch, those not being transported should be given drinking water and feed within 24 hours. After most chicks have hatched, if there are still individual chicks that have not hatched, manual assistance is needed. When assisting, first tap with the hand; if an empty hollow sound is heard, it indicates the blood vessels have dried up. When assisting, pull the chick's head out and let it slowly hatch on its own. If the chick is adhered to the egg membrane, warm water can be used to soak it, and it can be gently pulled apart. If bleeding occurs during assistance, stop immediately.

XIV. Cleaning and Disinfection After Hatching

After each hatching, the hatcher, hatching trays, egg trays, hatching room, etc. should be cleaned and disinfected. Dead embryo eggs and eggshells should be harmlessly treated. For incubators that integrate incubation and hatching, when cleaning, note that the temperature inside the machine cabinet should not be too low; the room temperature can be raised before cleaning.

XV. Causes of Embryonic Death at Each Stage of Incubation

1) Early-stage death (1-6 days): poor nutritional level and health status of breeding chickens, mainly lack of vitamin A and vitamin B2; breeding eggs stored too long, storage temperature too high or frozen; improper fumigation disinfection of breeding eggs; incubation temperature too high in the early stage; breeding eggs subjected to severe vibration during transportation; heredity. 2) Mid-stage death (7-12 days): poor nutritional level and health status of breeding chickens, such as lack of vitamin B2; the peak of embryonic death is on the 9th to 14th day; when lacking vitamin D3, edema appears; dirty eggs not disinfected; incubation temperature too high; poor ventilation; if the allantois has not closed, besides retarded development, it is mostly caused by improper egg turning. 3) Late-stage death (13-18 days): poor nutritional level of breeding chickens, such as lack of vitamin B12; embryos mostly die on the 16th to 18th day; small air chamber, caused by excessively high humidity; if the embryo shows obvious congestion, it indicates a period of high temperature; extremely rapid weakening of development is caused by excessively high temperature; pecking at the small end is caused by poor ventilation or placement in incubation with the small end up. 4) Smothered to death inside the shell: excessively high temperature and humidity during hatching and poor ventilation can cause embryonic cartilage deformity, abnormal fetal position; rupture of the yolk sac, paralysis and weakness of the neck and legs, etc. 5) Death after pipping: if there is much mucus at the pip hole, it is caused by high temperature and high humidity; poor ventilation on the 20th to 21st day; when the embryo is utilizing protein, encountering high temperature before the protein is fully absorbed. If the allantois closes poorly and the yolk has not entered the abdominal cavity, it is due to a sudden temperature drop when transferring trays.

XVI. Handling of Power Outage Accidents

Units using electric incubation should be equipped with a backup generator so that they can supply power themselves in case of a power outage. If power cannot be supplied or the electric incubator malfunctions, the following emergency measures should be taken: when the room temperature is above 21°C and the power outage lasts within 15 hours, the machine door and ventilation holes can be closed to prevent excessive temperature drop inside the machine. When the room temperature is low, try to raise the room temperature. For eggs with an embryo age of 11 days or more, because they themselves produce a large amount of physiological heat, when the internal fan stops, the upper layer temperature often becomes higher than the lower layer. At this time, adjust the trays up and down once every 6 hours, or shake the fan for 2-3 minutes every half hour, so that the temperature inside the machine becomes uniform from top to bottom. If the embryo age is already above 16 days, check the egg temperature at any time, adjust trays once every 2-3 hours, open all inlet and outlet ventilation fans, and appropriately lengthen the fan-shaking time to disperse excess accumulated heat inside the machine. When the room temperature exceeds 30°C during a power outage, open the machine door, and after discharging the heat inside the machine, close the door again. For eggs with an embryo age of more than 10 days, even more attention must be paid, otherwise overheating can easily occur and cause accidents.