1. Egg quality: Abnormal eggs and quality decline caused by age and improper management of breeding chickens.
2. Malnutrition in breeding chickens: Decreased hatching rate due to incomplete nutrition (especially vitamin deficiency) or toxic substances in the feed.
3. Genetic factors: Within the same breed, the hatching rate of inbreeding eggs is low and there are more weak chicks, while the hatching rate of healthy chicks in hybrid chicken eggs is increased. There are also phenomena such as low genetic fertilization and hatching rates.
4. Problems in incubation management work
(1) On the first and second days of incubation, if the temperature is too high: some embryos develop well, but there are more malformed fetuses, especially those with head and eye deformities. Early hatching and low weight.
(2) On the 3rd to 5th day of incubation, if the temperature is too high, the urinary bladder will "close" prematurely, the embryo will be ectopic, and there will be multiple deformities in the heart, liver, and stomach. Early hatching, but irregular hatching and prolonged time.
(3) Short term intense high temperature: occurs on the 5th to 6th day of human incubation, when the embryo is dry and moving on the eggshell; If it appears on the 10th. After 11 days, the blood vessels in the urinary bladder will appear dark gray and the blood will be thick; If it occurs in the later stage, bleeding points can be seen on the embryonic skin, heart, liver, and kidneys. Ectopic dead embryo, with the head bent between the left wing and legs. There are also scattered bleeding on the skin and heart. Wrinkles appear in advance, with uneven wrinkles and varying sizes.
(4) During the second half of incubation, if the temperature is too high, many people will hatch early but die quickly after pecking. Early hatching and prolonged time, poor absorption of yolk in chicks. The yolk sac, intestine, and heart are responsible for blood loss. Chicks are weak, have poor healing of the navel and often bleed, and there are blood pollutants inside the shell.
(5) Incubation temperature is too low: embryo development is very slow, and on the 19th day, the air boundary is almost uniform. Egg yolk is absorbed into the abdominal cavity and appears green, while the intestine is filled with egg yolk and meconium. Embryonic urinary bladder congestion and cardiac hypertrophy. The hatching time is delayed and prolonged, and the resilient chicks are weak and have a large belly, unable to stand steadily, occasionally suffering from diarrhea, and the eggshells are dirty.
(6) Excessive humidity: The time for the embryo's bladder to "close" is delayed, and by the 19th day, the boundary line of the chamber is still aligned, resulting in a slow reduction in egg weight. When pecking at the shell, it sticks to the eggshell while the dead embryo's ear sacs, stomach, and intestines are filled with cystic fluid. The hatching time is delayed and delayed, the chick's belly is large and weak, and the fuzz adheres to the eggshell.
(7) Low humidity: On the 5th to 6th day of incubation, there is an increase in dead embryos that sit on the eggshell. However, on the 1st to 11th day, the egg weight decreases too quickly. The shell is difficult, and the chick's fur is sparse, short, and dry.
Embryo congestion and early shell pecking
(8) Poor ventilation: The number of dead embryos increases on the 5th to 6th day of incubation, and on the 10th day. On the 11th day, there was blood mixed in the amniotic fluid, and on the 19th day, there was visceral hemorrhage and bleeding in the embryo. Chickens often peck at the small head of the egg, resulting in uneven hatching and a higher number of weak chicks.
(9) Abnormal egg flipping: such as too few egg tossing times or too small an angle each time, reaching the 5th position. On the 6th day, the yolk of the embryo adhered to the shell membrane. On the 10th and 11th day of egg testing, it was observed that the urinary sac had not yet enveloped the protein. On the 19th day, there was still residual protein outside the urinary sac.
2. Malnutrition in breeding chickens: Decreased hatching rate due to incomplete nutrition (especially vitamin deficiency) or toxic substances in the feed.
3. Genetic factors: Within the same breed, the hatching rate of inbreeding eggs is low and there are more weak chicks, while the hatching rate of healthy chicks in hybrid chicken eggs is increased. There are also phenomena such as low genetic fertilization and hatching rates.
4. Problems in incubation management work
(1) On the first and second days of incubation, if the temperature is too high: some embryos develop well, but there are more malformed fetuses, especially those with head and eye deformities. Early hatching and low weight.
(2) On the 3rd to 5th day of incubation, if the temperature is too high, the urinary bladder will "close" prematurely, the embryo will be ectopic, and there will be multiple deformities in the heart, liver, and stomach. Early hatching, but irregular hatching and prolonged time.
(3) Short term intense high temperature: occurs on the 5th to 6th day of human incubation, when the embryo is dry and moving on the eggshell; If it appears on the 10th. After 11 days, the blood vessels in the urinary bladder will appear dark gray and the blood will be thick; If it occurs in the later stage, bleeding points can be seen on the embryonic skin, heart, liver, and kidneys. Ectopic dead embryo, with the head bent between the left wing and legs. There are also scattered bleeding on the skin and heart. Wrinkles appear in advance, with uneven wrinkles and varying sizes.
(4) During the second half of incubation, if the temperature is too high, many people will hatch early but die quickly after pecking. Early hatching and prolonged time, poor absorption of yolk in chicks. The yolk sac, intestine, and heart are responsible for blood loss. Chicks are weak, have poor healing of the navel and often bleed, and there are blood pollutants inside the shell.
(5) Incubation temperature is too low: embryo development is very slow, and on the 19th day, the air boundary is almost uniform. Egg yolk is absorbed into the abdominal cavity and appears green, while the intestine is filled with egg yolk and meconium. Embryonic urinary bladder congestion and cardiac hypertrophy. The hatching time is delayed and prolonged, and the resilient chicks are weak and have a large belly, unable to stand steadily, occasionally suffering from diarrhea, and the eggshells are dirty.
(6) Excessive humidity: The time for the embryo's bladder to "close" is delayed, and by the 19th day, the boundary line of the chamber is still aligned, resulting in a slow reduction in egg weight. When pecking at the shell, it sticks to the eggshell while the dead embryo's ear sacs, stomach, and intestines are filled with cystic fluid. The hatching time is delayed and delayed, the chick's belly is large and weak, and the fuzz adheres to the eggshell.
(7) Low humidity: On the 5th to 6th day of incubation, there is an increase in dead embryos that sit on the eggshell. However, on the 1st to 11th day, the egg weight decreases too quickly. The shell is difficult, and the chick's fur is sparse, short, and dry.
Embryo congestion and early shell pecking
(8) Poor ventilation: The number of dead embryos increases on the 5th to 6th day of incubation, and on the 10th day. On the 11th day, there was blood mixed in the amniotic fluid, and on the 19th day, there was visceral hemorrhage and bleeding in the embryo. Chickens often peck at the small head of the egg, resulting in uneven hatching and a higher number of weak chicks.
(9) Abnormal egg flipping: such as too few egg tossing times or too small an angle each time, reaching the 5th position. On the 6th day, the yolk of the embryo adhered to the shell membrane. On the 10th and 11th day of egg testing, it was observed that the urinary sac had not yet enveloped the protein. On the 19th day, there was still residual protein outside the urinary sac.
