The most important thing for the farmers who raise the cows is to increase the breeding rate of the cows. The high rate of cow breeding also means the income of the farmers. Let's take a look at the main points of cow breeding techniques.

First, sexual maturity

When the yak grows and develops to a certain extent, the reproductive organs are mature and have reproductive ability, which is called sexual maturity. The age of sexual maturity of cattle varies with breed, feeding management, climatic conditions, nutritional status and growth and development. Under normal circumstances, cows reach sexual maturity at 8-12 months of age. Generally, the age of the cow is 18-24 months old, and the body weight is 65%-70% of the adult body weight. It is too early to affect its development. But it should not be too late, otherwise it will reduce the number of calves produced in a cow's life, which is detrimental to production.

Second, the estrus cycle (also called the sexual cycle)

Cyclical estrus is in the absence of pregnancy before the cow matures from sexual maturity to age. The interval between the beginning of this estrus and the beginning of the next estrus is called the estrus cycle. Cows have an average estrus cycle of 21 days and a range of 18-24 days. Normal young cows are shorter than cows.

When a cow is in estrus, a series of physiological changes occur inside and outside the body. According to these changes, estrus can be divided into four periods: one is the pre-estrus period, when the cow's gonad activity is strengthened and the secretion is increased, but it is still not seen. There is mucus in the vagina, and there is no sexual desire. The second is estrus. During this period, the cow showed strong sexual excitement, the genital tract was obviously congested, the labia was swollen, the cervix was opened, the gland activity was enhanced, and mucus was discharged from the vagina. If the egg is fertilized, that is, after the cow is pregnant, the estrus cycle stops until the estrus cycle reappears after delivery. If the egg is not fertilized, it will be transferred to the late stage of estrus. Third, in the late stage of estrus, the corpus luteum was formed in the ovary after ovulation, and the estrus performance disappeared and returned to its original state. The fourth is the rest period, also known as the intercourse period. From the last estrus to the time before the next estrus, there was no change in sexual organs, no sexual activity, and a physiologically relative state of rest.

Third, the duration of estrus

The period from the beginning of the cow's external estrus performance to the end of the external estrus performance is called the estrus duration. The duration of estrus in cows varies depending on age, nutritional status and seasonal changes, usually 18 hours, ranging from 6 to 36 hours. The ovulation time of the cow is 12-15 hours after the end of estrus. These basic knowledge are the key to choosing the time of insemination. The breeder should be notified in a timely manner to ensure successful breeding.

Fourth, cow estrus identification

Estrus identification is a comprehensive technique to determine the estrus phase of the cow and determine the optimal breeding time so that artificial insemination can be carried out in time to maximize the breeding rate. There are many methods for identifying estrus, such as external observation, trial, vaginal, rectal, and biomimetic methods. It is believed that in the absence of advanced equipment, the most important is the external observation method. I will focus on this method below:

Cows are excited when they are in estrus, sensitive to changes in the external environment, looking around, losing their appetite or not eating, sometimes screaming, chasing bulls, climbing other cattle, and accepting other cattle. When the other cows climbed across, the cows opened their hind legs and lifted their tails to urinate. The genital area is swollen, and the mucus flows out from the vagina; when the estrus is high, the amount of mucus is large, thin and transparent. As the estrus time prolongs, the amount of mucus gradually decreases, becoming thick and turbid. At this point the cow lay down and the mucus dipped on the tail, leaving a lot of sand on the tail. At the end of estrus, there is sometimes a small amount of blood in the mucus, which is more common in young cattle. A few cows estrus, a small amount of dark red liquid from the vagina when lying in the ground, called "bulk menstruation." There are a few cattle that have no obvious external changes when they are in estrus, that is, the symptoms of estrus are not obvious, and they are called “dark estrus” or “quiet estrus”.

Five, insemination time

The ovulation time of the cow is 12-15 hours after the end of the external performance. After the egg is discharged, the time to maintain fertilization in the fallopian tube is 8-12 hours. Therefore, the time of insemination is arranged 6-8 hours before ovulation, and the conception rate is the highest. However, the ovulation time is not easy to grasp accurately, and it is easier to master the time of insemination according to the estrus time, and the insemination is better in the late estrus.

The above are the main points about cow breeding technology. The cattle-raising friends can refer to the study. If you have other questions during the cow breeding process, you can leave a message!

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