Sperm and egg transport in the uterus and survival time

After the mature egg is excreted from the ovary, its survival time is limited, and the survival time of the sperm in the uterus is also limited. The two times are well grasped. Artificial insemination at the right time can increase the conception rate.

1. Transportation of sperm in the womb

The transport of sperm in the womb mainly depends on the external force, the contraction of the uterus and the contraction of the tubal and the cilia swing to reach the site of fertilization. After the pig sperm enters the sow's reproductive tract, they will begin to "difficultly trek." Some of them are stored in uterine lacunae to form a number of sperm reservoirs. The sperm is released in these reservoirs to ensure that the site of fertilization is always constant. Fertilized sperm appear, waiting for the arrival of the egg.

Spermatozoa move forward along the sow's reproductive tract, showing a gradient-like decrease in density. The highest sperm density in the cervix is ​​more than 100 million spermatozoa, and the density of sperm in the upper segment of the fallopian tube is only 1000 (fertilized sites). This high selectivity of the porcine sperm and the large loss during operation make it possible for the more viable and active sperm to reach the site of fertilization, while also limiting the number of sperm that reach the site of fertilization, while the vast majority of sperm are Be swallowed or killed by white blood cells.

2. Time for sperm to maintain fertility

The time for sperm to maintain fertilization after excretion from the boar is 24-42 hours. The survival time of the sow's egg is only 8-12 hours, and it is only possible to obtain a good conception rate when the sperm and egg are in good vigor. When one of the sperm or egg ages, it will lead to a decline in the conception rate, which shows that the correct estrus identification and timely insemination is crucial to improve the conception rate.

3. Loss of sperm

Intensities or tensions that lead to increased uterine contractions will reduce the number of effective sperm, and the phagocytosis of white blood cells will also result in loss of sperm. In addition, the uterus or fallopian tubes may produce anti-sperm antibodies that reduce energy levels.

4. Egg transport

The sow's egg can enter the opercula of the fallopian tube from the surface of the follicle, and quickly enters the fertilized part of the pot-gap junction along the thin-walled umbrella.

5. The aging of the egg

If the egg enters the site of fertilization after being discharged but fails to meet the sperm and fertilize in time, the egg will soon age. This change is very obvious at 12h after ovulation, thus indicating that mating or artificial insemination must be performed at a suitable time before ovulation, otherwise the egg may be aging. Based on the rate of sperm running in the sow's reproductive tract and the time it takes to maintain fertilization, it is ideal to inseminate or breed 12-14 hours before ovulation. As the number of ovulation of pigs is more, there is a certain time interval.

6. Fertilization

Capability: Ejaculated sperm must undergo a final maturation process in the sow’s reproductive tract to be fertilized. The duration of capacitation of a pig's sperm is approximately 2-3 hours. After gaining energy, the sperm's swimming ability and respiratory intensity are increased. This is necessary for fertilization.

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