The metabolism of chicken embryo depends on the activities of various enzymes (such as amylase, protease, oxidase, lysozyme, etc. ) In eggs, the activity of enzymes is restricted by temperature. The temperature required for the strongest enzyme activity is the most suitable temperature for embryo development, which is the principle of incubation.
Second, the incubation conditions
Hatching technology can be divided into electric hatching, native chicken hatching or domestic chicken hatching. The incubation period is 2 1 day. The key points of incubation are as follows:
1. temperature: 1 ~ 18 days after hatching, 37.8℃ ~ 38℃ in winter and 37.5℃ in summer. /kloc-it was transferred to the incubator on 0/9, and the temperature inside the incubator was 37.2℃ in winter and 37℃ in summer.
2. Humidity: the relative humidity requirements are 1 to 18, 60%, 19 to 2 1 70%. The humidity control method can be to add a water tray in the machine or spray warm water on the surface of eggs 3-4 times a day. 3. Turn the egg: Turn the egg every 2 hours at an angle of 45 degrees.
4. Take pictures of the eggs: just hatch for 6 ~ 7 days.
Third, the brooding technology of Yuanbao chicken
It is best for newly hatched chicks to enter the market after Qingming, because the temperature will gradually warm up and the climate is suitable for chicks to grow, and no other insulation equipment is needed. Too low temperature will adversely affect the growth and development of hens, and it is easy to cause colds, respiratory infections, dysentery and other diseases.
1. heat preservation: heat preservation should be carried out within 1 ~ 30 days after chicks are hatched, and it is appropriate to evenly distribute them under heat preservation lamps.
2. Feed: Ordinary chicks can be fed with pellet feed. If conditions permit, 4% imported fish meal and 6% feed yeast powder can be added, which can increase the protein content of chick feed from 22% to 28%, which is more suitable for the growth and development of female chicks. Feed is free all day.
3. Drinking water: provide enough clean drinking water all day, especially warm water in winter.
4. Density: more than 100 can be raised per square meter, and gradually evacuated to 50-60 with the increase of age. At the same time, pay attention to changing the padding every day.
5. Careful observation and prevention: Observe the spirit, appetite, feces and breathing of chickens every day, and carry out preventive vaccination or drug feeding according to the epidemic situation of domestic chickens in various places.
Fourth, the structure and formation of the seed eggs of Yuanbao chicken
1. The structure of breeding eggs consists of seven parts: eggshell, eggshell membrane, air chamber, protein, yolk, lace and embryo.
2. Eggs are formed in the reproductive organs of hens. The reproductive organs of hens mainly include ovaries and fallopian tubes.
Five. Selection, Preservation, Transportation and Disinfection of Seed Eggs of Yuanbao Chicken
1. Selection of breeding eggs
The quality of eggs is closely related to the hatching rate, the quality of newborn chicks, their health, vitality and production performance. Therefore, we must choose eggs carefully and strictly according to the specific situation. The so-called egg breeding refers to the eggs laid by male hens after mating in groups according to a certain gender ratio or through artificial insemination.
(1) The source of breeding eggs must come from high-yield healthy chickens in non-epidemic areas. Only when the ratio of male to female is appropriate can the fertilization rate be high, and the fertilization rate of breeding eggs should be above 80%. The eggs of the first-born hen within half a month should not be used as breeding eggs, because the hen's sexual activity is poor at this time, so the fertilization rate is low.
(2) Preservation period of eggs The fresher the eggs, the better. It is generally better to keep eggs within one week. The storage period shall not exceed 10 day in summer and half a month in spring and autumn.
(3) The color of eggshells should conform to the characteristics of varieties. For example, eggs in Hangzhou are white, while Luodaohong, Bailuoke and local chicken are brown, indicating that the varieties are impure.
The eggshell thickness of Yuanbao chicken (4) should be dense and moderate. Too thick is not conducive to hatching, too thin is easy to break. Eggshells that are dull, rough, with sand holes (called sand preserved eggs) or hard shells (called steel preserved eggs) and wrinkled skins cannot be used as breeding eggs. Generally, the shell thickness should be between 0.2 and 0.4 mm, and the hatching rate is the highest when the shell thickness is between 0.33 and 0.35 mm, and the hatching rate is lower when the shell thickness is below 0.27 mm.
(5) The size and shape of the eggs depends on the variety, generally between 45 and 65 grams. Sailing boats should be in the range of 45 ~ 50g, babcock B-300 should be in the range of 50 ~ 60g, and other dual-purpose species should be in the range of 50 ~ 65g. The shape of an egg should be normal. Abnormal eggs such as too big, too small, too long, too round and bulging eggs are not suitable for breeding eggs, and double yellow, three yellow, eggs in eggs, blood spots and meat spots are not suitable for breeding eggs.
(6) The surface of eggs should be clean and hygienic, such as feces, sludge, feed, etc. , easy to be invaded by bacteria, leading to egg rot or stillbirth.
Yuanbao chicken 2. Storage conditions of breeding eggs The critical temperature of chicken embryo development is 23.9℃, so the environmental temperature of breeding eggs should be kept at 10 ~ 15℃, and should not exceed 12℃ if the storage period is long. The humidity should be 70% ~ 75%. Eggs should be placed upside down. If they are upside down, they must be turned once a day.
3. Pay attention to the packaging when transporting eggs to prevent vibration. Eggs should be packed in a grid box, and each egg and each layer of eggs should be separated and filled with fillers, such as scraps of paper or broken grass. The stuffing must be full, and the eggs should be placed vertically with their heads up to avoid vibration during transportation. Egg boxes should be kept clean and dry. 4. Disinfection of breeding eggs In order to control and eliminate the spread of pathogenic microorganisms and ensure the health of chicks, breeding eggs must be disinfected before hatching. The following are several commonly used disinfection methods:
(1) disinfection method of bromogeramine: 5% of bromogeramine stock solution. When in use, 50 times of water is added to make the concentration of 1/1000 (0.5 kg of 5% bromogeramine stock solution is poured into 25 kg of clear water and stirred evenly) and sprayed on the surface of eggs. But this solution cannot be mixed with alkali, soap, iodine and potassium permanganate.
(2) Chlorine disinfection method: soak eggs in bleaching powder solution containing 1.5% available chlorine for 3 minutes (that is, add 0.75 kg of bleaching powder containing available chlorine to 50 kg of water) and drain.
Yuanbao Chicken (3) Potassium Permanganate Disinfection Method: Soak the eggs in a potassium permanganate solution with a concentration of two ten thousandths 1 ~ 2 minutes (that is, add 10g potassium permanganate powder to 50 kilograms of water, stir well and drain.
(4) Iodine solution disinfection method: prepare iodine into 0. 1% iodine solution, and spray it on the egg surface (iodine solution with 1.5 times of potassium iodide is needed to facilitate iodine dissolution). Specific preparation method: add 10g iodine tablets and 10g potassium iodide into 10g water to dissolve, and then pour into 9kg of clean water.
(5) Formalin disinfection method
① Fumigating with formalin (40% formaldehyde stock solution or industrial formaldehyde) and potassium permanganate. Fumigating with 15g potassium permanganate and 30ml formalin solution for 30-45min per cubic meter. The method is as follows: put the eggs into a dish and put them into an incubator or a bed, then put potassium permanganate evenly into a container (the amount of the container is more than that of formalin 10 times), then pour in formalin and close the doors and windows.
② Formalin fumigation directly. Add formalin to the right amount of water with the same standard amount as the above method, and put it directly on the stove for heating and fumigation.
③ Formalin soaking disinfection method. Mix 40% formaldehyde stock solution into 1.5% solution (that is, pour 0.75 kg formalin into 50 kg water) and soak the eggs for 2 ~ 3 minutes.
(6) Soak the eggs in the antibiotic solution and raise the temperature to 38℃. After 6-8 hours, put the eggs into the prepared solution of oxytetracycline or streptomycin (that is, add 25 grams of oxytetracycline or streptomycin into 50 kilograms of water and mix them evenly) and soak for 10- 15 minutes.
(7) Disinfection method of nitrofurazone solution: grind nitrofurazone into powder, then prepare 0.02% aqueous solution to soak eggs for 3 minutes, then wash and dry.
(8) Ultraviolet disinfection method: install a 40-watt ultraviolet lamp at a height of about 1 meter from the ground and irradiate 10 ~ 15 minutes to achieve the purpose of disinfection.
Embryonic development of Yuanbao chicken.
1. Division of development stages of chicken embryo hair The whole development can be divided into two stages: the development stage of eggs and the development stage of chickens.
(1) The development of embryo in the process of oogenesis is the development in the mother, that is, the development in the stage of oogenesis. The development process of this stage is: zygote cleavage blastocyst stage and gastrula stage. When the embryo develops to gastrula stage, it has differentiated into endoderm and ectoderm. From the appearance, it looks like a disc-shaped body, which is the blastoderm. When the egg is excreted, the growth and development of the embryo will stop immediately due to the drop in temperature.
(2) Embryo development is basically in a static state after the eggs are discharged during hatching and placed in an environment below 65438 08℃. When people hatch, embryos begin to develop. The period during which an embryo develops during incubation is called incubation period. The incubation period of chickens is 2 1 day.
After the egg breeder hatches, the embryo is formed in the gastrula stage, and the upper germ layer is disc-shaped. At its end, the cells continuously converge to the midline, forming a cell band, which is called the original band. Primitive cells gradually transfer between human ectoderm and endoderm through the bottom of primitive groove, and expand to both sides respectively. These cells located between endoderm and endoderm are called mesoderm. Primitive cells also gradually transfer between human ectoderm and dermis, and stretch forward respectively. The stretched structure is called cephalic process, and then it develops into notochord. The notochord is the longitudinal supporting organ in the embryonic stage, which is eventually replaced by the spine. With the continuous development of embryos, various glands, organs, bones, muscles, skin, feathers, beaks, etc. are gradually formed from ectoderm, mesoderm and endoderm, and finally a new organism-chick is formed.
Yuanbao chicken 2. The formation of fetal limb and its material metabolism The development of embryo includes two parts: the inside of embryo is the development of embryo itself; The extraembryonic part is the formation of embryo membrane. The respiration of embryo nutrition and substance metabolism is mainly realized through embryo membrane. Embryo membrane includes four parts:
(1) Amniotic membrane and chorion began to appear about 33 hours after hatching, covering the head of the embryo and gradually surrounding the embryo the next day. On the fourth day, they close and surround the embryo, forming two layers of membranes, one near the inner layer of the embryo is called amniotic membrane, and the other around the whole egg content is called chorion. The chorion and allantois form the chorion of allantois. The amniotic cavity is filled with amniotic fluid, which protects chickens from mechanical damage, prevents fetal membrane adhesion and promotes chicken embryo movement.
(2) The yolk sac is an early embryo membrane, which began to form on the second day after hatching, and then gradually spread to the surface of yolk, and surrounded the yolk 1/3 on the fourth day, the yolk 1/2 on the sixth day, and almost covered the whole yolk surface on the ninth day. There are many blood vessels on the yolk sac, and T forms a circulatory system, which connects the human embryo body for the embryo to absorb water and nutrition from the yolk. The yolk sac has the function of exchanging gas with the outside world in the early stage of hatching, and is sucked into the abdominal cavity with the yolk before hatching.
(3) The allantois is located between amniotic membrane and yolk sac. It began to form on the second day after hatching, and then gradually increased. On the sixth day, it reached the inner surface of eggshell membrane, and when it hatched from 10 to 1 1, it surrounded the whole egg content and closed at the small end of the egg. While the allantois is in contact with the inner wall of the egg and continues to develop, it combines with chorion to form allantois chorion, which attaches to the eggshell and begins to play the role of gas exchange. At the same time, the minerals in the eggshell are absorbed by the blood vessels of the allantoic sac for the embryo, all the excreta of the embryo are accumulated in the allantoic sac, and the allantoic sac is filled with allantoic fluid to separate the embryo from the eggshell, so as to protect the embryo.
During the incubation process of Yuanbao chicken, the metabolism of embryonic substances mainly depends on the development of fetal membranes. After two days of incubation, the blood circulation of yolk sac begins to form, at this time, the embryo mainly absorbs nutrition and oxygen from yolk sac; After 5 ~ 6 days of incubation, the blood circulation of allantois is formed. At this time, the embryo absorbs nutrients from egg yolk and eggshell through the blood circulation of allantois. Because the allantois is close to the eggshell membrane, it can also absorb external oxygen through allantois circulation; After hatching 10 ~ 1 1 day, the allantois closed, the material metabolism and gas metabolism of the embryo were greatly enhanced, and the egg temperature increased. After hatching to 18 ~ 19 days, protein was exhausted, allantois withered, and lung respiration began. The yolk sac absorbs nutrition from the yolk, which strengthens the fat metabolism and increases the respiratory ability.
In practice, special attention should be paid to the difference of gas metabolism before and after incubation. Generally, the oxygen consumption of chicken embryos at the end of incubation is 64 times that of the initial stage, the exhaled carbon dioxide is 1.46 times that of the initial stage, and the heat production is 230 times that of the initial stage. Therefore, it is necessary to reasonably arrange the external conditions required for each stage of embryonic development.
3. The main characteristics of embryonic development
In order to understand the development of embryos, correct the unfavorable hatching environment factors in time, and master the main characteristics of embryo development is necessary.