The best period for insemination of cows, experts call the second half of the hunt. Not only the level of herd reproduction, but also its milk production depends on the timeliness of determining this phase. We will discuss the methods of definition and the signs of a favorable moment in the cow's sexual cycle, as well as the reasons for false desires, later in the article.

What is and how long does a cow hunt last

Cattle in zoology are classified as a polycyclic group. This means that due to hormonal modifications that are repeated in the body with an interval of 18-24 days, the duration of the sexual cycle in heifers does not exceed 21 days.

Initially, the animal undergoes a stage of excitation, which is accompanied by the maturation of the egg and an increase in the concentration of estrogen in the blood. This is the period of the onset of estrus and ovulation. It occurs approximately 24 hours after mucus begins to secrete from the swollen genital organs of the animal. In the behavior of the heifers, anxiety and increased activity are observed.

Important! Veterinarians advise fertilization of heifers 12 hours after the onset of estrus.

After this, the inhibition stage starts, which is characterized by intensive production of luteinizing hormone, on the 2nd – 5th day. It, in turn, provokes the production of progesterone, which stimulates the formation of a yellow body follicle in place of an erupted follicle. The female becomes calmer, and the mucus secreted from her vagina visibly thickens.

Then the equilibrium phase begins, when the level of estrogen in the animal’s blood rapidly decreases and the amount of progesterone rises. This period lasts about 15-16 days and is characterized by complete calmness of the cow, as well as the rejection of the insemination bull.

Clear signs of hunting

In modern veterinary medicine, there are many ways to determine cow hunting in household and large-scale farming. But they are all based on the outward signs of this cyclical process. In particular, we are talking about:

• restless behavior;
• decreased appetite;
• increased motor activity (the animal constantly rushes about in the pen or in the pasture, breaks with a leash);
• rapid breathing and palpitations;
• fever (not always);
• decrease in the number of milk yield;
• showing interest in the bulls (the female lets them in and allows her to jump onto her back);
• possible interest in the genitals of other cows (the heifer, which is in the hunting stage, can itself jump on its other relatives in the herd);
• swelling and redness of the genitals (a symptom is observed from the first hours of estrus);
• excessive moisture of the vulva;
• highly visible mucous secretions from the cow vagina of different consistencies (initially they are transparent and liquid, and eventually become cloudier and thicker, in the final phase they become viscous, sticky, cord-like; it should be noted that this process is characterized by periodicity);
• possible bleeding;
• relaxation of the uterine neck and its openness.

Did you know? Cows sense the Earth's magnetic field and position their body while feeding and resting along its lines of force.

How to Identify a Cow's Hunt: Common Methods

Initially, the process of determining the sexual cycle in heifers seems overly simple. In the private economy, there are enough elementary observations of the horned ward. But what about the zoo engineers of large farms? In practice, modern instrumental methods help them out. Let's consider them in more detail.

Video: cow in the hunt

Thermometry (body temperature measurement)

This method, like all others, does not guarantee absolute certainty in the accuracy of the conclusions made. Its implementation provides for the presence of a special thermometer, which is introduced to the animal in the cloaca or genitals. The essence of the study is to study the dynamics of temperature changes in a cow's body over several days. If the female has started the hunting phase, the thermometer column will rise 2 marks higher compared to the previous day. Some farmers practice calculating the average temperature of heifers in 48–72 hours.

Important! Of all the existing methods for determining sexual cyclicity in female cattle, the so-called fern leaf method is. It provides a laboratory study of the mucous secretions of cows, which at the time of estrogenic activity under the microscope take the form of a fern. The disadvantage of this method is the complexity of the fence of the cervical substance and the risks of infectious invasion.

In any case, during the readiness for breeding, the female’s body will be 2-3 degrees hotter. In addition, in thermometry there is a reading of indicators from freshly milked milk. It is important to measure its temperature precisely at the moment it enters the milking machine or other container. In fairness, we note that this method works only in 27% of cases, since estrus is not always accompanied by this symptom. In addition, the appearance of heat in a cow can be caused by infectious diseases, subclinical mastitis, or other pathological factors.

Test bulls

This type of testing involves the presence of neutered one-year-old males. In large agricultural enterprises, 200 females use one probe bull. Initially, it is kept in conditions isolated from the herd and daily released in the morning and evening for 1.5–2 hours into the pens to the heifers, after which they monitor their behavior. If the female lets the bull in and shows interest in him, she is in the hunt. Such a ward must be removed from the pen to search for other pets.

Important! The degree of reproductive activity in cows is affected by the level of feeding and overall fatness. In lean individuals with a poor nutritional diet, hunting is very slow and sluggish. The same picture is observed in obese females with unbalanced nutrition .

Characteristically, this method allows to determine with accuracy up to 95% not only the sexual activity of cows, but also the onset of pregnancy, as well as infertility. Veterinarians advise when observing the time frame for different categories of cows, namely:

• After calving, check the animals by the test bull for 3-4 days;
• inseminated individuals - from 10 to 30 days after mating.

In large farms, where hundreds of cows are kept and it is practically impossible to track their sexual arousal when in contact with a test male, a special device is used for testing (it is fastened with straps to the bull’s chin), leaving colored marks on estrogenically active females. They need to be looked for in the interscapular area of ​​cows, which is due to the operation of the tap during cage.

Pedometry (measurement of motor activity)

This method is based on observational practice of the motor activity of a horned ward. At home, it does not require any equipment, which cannot be said about research conducted on large farms. There pedometry is based on indicators of mechanical or electrical pedometers that fasten to the legs of animals. Data must be recorded 2 times a day.

After that, the analysis of the dynamics of the taken measurements for the last 3-5 days is done. With an increase in hormonal activity, the cow will experience an increase in locomotor activity. Some devices fix it automatically with a red glow. In the private economy, the animal entering the hunting phase is eloquently indicated by its throwing on the paddock and jumping onto the backs of its relatives.

Instrumental method

Based on the analysis of the manifestation of secondary signs. To fix them, often in the area of ​​the first caudal vertebra of the females a thick line is drawn with chalk or other printing markers. An excited individual allows other members of the herd to jump onto their back, exhibiting “hug reflexes”. As a result, the mark loses its clarity. Practicing this method, veterinarians note a high level of false-positive results, so it is not recommended to rely only on the findings of an instrumental study.

Did you know? Cows are extremely observant animals. For example, if one individual is shocked, and the whole herd will notice, then most horned animals will not approach the source of danger.

Heat detector

The method involves the presence of an electronic device that determines the exact time of cow ovulation. The efficiency of the estrus detector is very high. Studies are based on an analysis of the electrical resistance of mucus secreted from the vagina.

The point meter determines the optimal period of insemination and confirms the early gestation period (from 19 to 23 days after insemination). If there is no pregnancy on these days, the next hunt occurs, which can be detected with this device.

Why is a false hunt

Sometimes it happens that the boobyon shows interest in individuals of the opposite sex, but does not come to the hunt. Veterinarians explain the long absence of estrus for various reasons:

• conception;
• weak severity of symptoms (depending on the individual characteristics of the animal);
• pathology of the ovaries (most often a cyst is diagnosed);
• prolonged recovery of the body after calving (takes place after a complicated form of childbirth);
• hormonal imbalance (caused by malfunctions of the internal organs and systems);
• poor conditions of detention;
• poor nutrition;
• regular overfeeding and obesity.

Against the background of changes in the cow's body, which are caused by hormonal failure, signs of false hunting are clearly manifested. In this case, the female can sniff the genitals of other individuals in the herd, either allow herself to carry out dorsal cage, demonstrate her anxiety and refuse to eat.

Important! Often the peak of symptoms of sexual activity in cows is observed between 6 a.m. and noon. The vast majority of animals remain in sexual hunting for about 18 hours.

Due to the occurrence of excitation, the probability of redness of the genital organs is high. But this is not a reason to draw conclusions about the reproductive activity of cattle. It is possible to distinguish false estrus from real estrogen by vaginal discharge of a heifer. In case of disruptions in the body, they are absent or appear in insignificant amounts. If the cow really needs a bull, the mucus will be visible on its tail, hips and stall.

Timely determination of estrogenic activity in cows is a very important point for reproducing the herd and maintaining satisfactory milk production. We hope our article will be useful to you in this.