In cow breeding, one of the important skills is to determine when a cow comes into heat. This is necessary in order to send her for mating or insemination on time. This determines whether the animal can become pregnant and give birth to a calf. Let's look at how to determine when cows come into heat after calving, how long it lasts, and what drugs to use to stimulate heat in cattle.
How many days does it take for a cow to come into heat after calving?
The appearance of heat can be expected 1-2 months after the next calving.The period depends on the conditions of detention and nutrition, the state of health of the animal, how the birth went (in severe cases, the period increases). If there are 1 or 2 cows in the household, it is quite easy to determine when she is walking. There are certain signs by which an experienced livestock breeder can find out whether his cow is in heat.
It lasts, on average, 18 hours; it is recommended to inseminate the animal in the middle of this time period - 9 hours after the start. If the animal takes too long, the likelihood of successful fertilization decreases. If the cow is not pregnant, the next time you need to try in a month (heat appears every 3 weeks).
Duration of re-hunting
To get a calf every year, you need to breed cows in the next cycles after calving. If pregnancy does not occur, mating is allowed in the next 1-2 repeat cycles. Each of them lasts the same number of hours as usual, that is, on average, 18 hours. The duration of estrus in cows is 2-6 days.
How to diagnose readiness
There are characteristic signs by which you can determine whether a cow is ready for insemination. At home, this can be recognized by the animal’s behavior - it becomes restless, moves a lot, moos, and eats less. You can almost unmistakably determine when it is time to happen by the fact that the cow allows other individuals, and not only bulls, but also females, to jump on her. At this time she stands calmly, motionless. Heat is also detected by external physiological signs: the cow secretes mucus from her genitals, which indicates its onset.
In animal husbandry there is such a thing as “silent” hunting. This is the state of the body of cows when the follicles mature and ovulation occurs, but there are no external signs or they are weak.This disruption of the reproductive cycle can occur in both cows and nulliparous heifers. The reasons for “silent” hunting are violation of housing conditions, feeding, lack of light or movement. Stress from moving to another house, herd, exposure to heat or high humidity.
To choose the best time for insemination, you need to take into account 2 criteria: the period after calving and the heat period. As for which cycle is best to fertilize animals, it is better to skip the first cycle, since it has been established that the functionality of the ovaries is restored faster than the uterus. A month after giving birth, the uterus may not yet be ready to bear a calf. The insemination itself is carried out 2 times with an interval of 10-12 hours, for example, in the morning, and the second in the evening. The interval for heifers may be shorter because they have a shorter period of heat.
How to use medicine to increase heat in livestock
There are drugs that, when introduced into a cow's body, can induce heat. For example, you can use the drug "Estrophan", its purpose is to stimulate and correct the reproductive cycles in adult cows and heifers.
It is used for functional disorders of the ovaries, postpartum endometritis, follicular cysts. The drug is administered intramuscularly, 2 times with an interval of 10 days. When, 2 weeks after the first administration, the animal goes on a spree, it happens, regardless of whether there are external signs of estrus. Repeated insemination is carried out the next day.
In addition to “Estrophan”, the drugs “Galapan”, “Gestavet”, “Surfagon”, “Estrovet”, “Fertagil”, “Folligon” and others are used. After using such veterinary medications, the cow begins to walk, and it can happen.
Rules for re-insemination
In animal husbandry practice, it has been revealed that the effectiveness of insemination depends on many factors, not only on the time when the cow comes into heat. The state of the body has a great influence - its health, nutrition, the presence or absence of diseases, and mental state. In first-calf heifers, labor can be prolonged, so it is recommended that it occur 2-3 weeks before the rest of the cows are mated, so that calving occurs at approximately the same time.
During artificial insemination, several individuals are inseminated with one dose of bull sperm, for which it may be necessary to adjust the timing of their onset of heat. Individuals that are planned to be inseminated must be examined every 2 weeks. If necessary, it is necessary to review the diet and improve the nutrition of animals, because overall fatness affects the functionality of the reproductive system, the manifestation of heat and its duration.
Due to insufficient nutrition, the maturation process of the follicles in cows is disrupted and they develop poorly. The same thing is observed in obese animals; their estrus duration is shortened.
Cows with calves may also have problems with their normal reproductive cycle. To improve fertilization results, it is necessary to synchronize heat. Calves are taken from their mothers before the procedure begins, then the cows are fed nutritious feed, vitamins and premixes to bring the body back to normal.Vitamin E is especially valuable during this period, as it regulates reproductive function. The lack of a substance in the feed directly affects the performance of the system. Such cows need to be sheltered no earlier than 2 months after calving.
Why does false hunting happen?
It happens that after a cow is inseminated, she again shows all the signs of heat, and it happens again. Pregnancy occurs, but based on the timing of birth, it turns out that fertilization occurred in the first mating. This means the second hunt was false.
This can happen due to low levels of progesterone, which is not enough in the cow’s body. It is excreted from the body with milk. False heat can be determined by performing an ultrasound of the ovaries. Insufficient levels of progesterone not only affect the occurrence of false heat, but because of it, the number of embryo deaths increases.
Reduced body condition also causes false heat in cows with high milk yields. Milk production requires a lot of nutrients and energy, which the animal’s body does not have time to replenish. Changes occur in metabolism and hormonal levels, suppression of follicles and delayed ovulation. The follicles form the corpus luteum, which synthesizes progesterone.
In milking animals, this condition can be caused by stress from overheating. During stress, the body produces the hormone cortisol, while the production of oxytocin and gonadotropic hormones decreases. As a result, the genesis of follicles and ovulation processes are disrupted. Signs of sexual heat become less intense.
Abortions are possible in pregnant individuals. Animals can be returned to their normal state by cooling the room using water or ventilation.Correct determination of the time of onset of estrus and the duration of heat in cows is important for further insemination. The effectiveness of mating depends not only on the quality of the sperm, but, above all, on when it entered the uterus. If you choose the right moment, the cow will become pregnant with almost 100% probability.
For large farms, the profitability of the entire farm depends on the effectiveness of mating, since the more animals become pregnant, the more calves can be obtained, and therefore greater profits. And in the household, this also matters. If you know how to determine the right time, it will be enough to carry out mating once, and not several in a row.
