Content
Corpus luteum in cows often leads to infertility. It happens that after insemination, pregnancy does not occur and the cow remains barren. In this case, it is necessary to establish the exact cause of the pathology, otherwise the animal may remain infertile.
What is the corpus luteum
Before artificial insemination, a favorable time is selected - the period when the female is in heat and follicle formation occurs. At a certain point, the follicle matures and the egg is released. Reaching one of the horns of the uterus, the egg is fertilized. At the site of the rupture of the follicle, a certain cavity appears, which is subsequently overgrown with vessels. Then it turns into a temporary endocrine gland - the corpus luteum.
After fertilization, the gland begins to produce biologically active substances that contribute to the development of pregnancy and fetal growth:
- steroids (progesterone, estrogen);
- peptides (oxytocin, relaxin);
- inhibin;
- cytotoxins;
- growth factors.
Progesterone and inhibin – sex hormones that have a positive effect on reproductive function.
Peptides – amino acids that regulate all physiological processes.
Cytokines – biological molecules that can coordinate the functioning of the immune, endocrine and nervous systems.
The gland continues to work in cows throughout pregnancy, until the calf appears.
If fertilization does not occur, the formed corpus luteum does not develop further and gradually disappears. After the next sexual cycle, when the individual is again in heat, the formation of a new follicle begins.
Reasons for the formation of the corpus luteum
The corpus luteum can sometimes linger in the ovary for various reasons, because the action of hormones prevents the follicle from maturing and releasing the egg. Although ovulation has occurred, due to some reasons the egg does not enter the uterus. In such cases, experts declare the persistence of the corpus luteum.
The corpus luteum is formed, works, and regresses through the interaction of the pituitary gland, ovary, and immune system. With pathology, a malfunction occurs in the entire hormonal system.
The main reason for the formation of the corpus luteum, as stated by veterinarians, is maternity paresis.
In some individuals, the disease recurs after each calving. Cows suffer from birth paresis mainly in the winter season, in whose feed proteins predominate. Recurrence of labor paresis can be avoided by properly balancing the feeding diet of pregnant cows.It is useful to give pregnant cows vitamin D, which contributes to the proper functioning of the entire reproductive system of the animal and favorable hormonal levels. Active exercise of cows is required until the first harbingers of labor. The disease can affect some parts of the brain, as well as the pituitary gland. If its functioning is disrupted, the hormone progesterone is released into the blood, which affects the formation of the corpus luteum.
There are a number of other reasons for the persistence of the corpus luteum:
- lack of active walking;
- poor feeding ration, which leads to metabolic disorders and hormonal problems in the cow’s body;
- lack of vitamins A, E, D, which are necessary for the proper development and gestation of the fetus;
- lack of mineral supplements in the diet, many of which have a positive effect on the nervous and reproductive system of the cow;
- increased content of concentrates in feed.
The reasons for the development of the corpus luteum also include a history of inflammatory diseases of the genitourinary system.
Signs of persistent corpus luteum
More often, cows do not show any signs of delayed release of the corpus luteum. On the contrary, the animal looks healthy outwardly and has a good appetite. Moreover, all the signs of hunting appear: mucus comes out of the vagina, the cow attacks the animals in the herd. But after insemination, pregnancy does not occur.
The diagnosis of persistent corpus luteum is made only after several unsuccessful insemination attempts. Then the cow is examined using an ultrasound machine and the rectal method, which is carried out 2 times at intervals of a month. The fact is that one examination may not reveal pathology, since the veterinarian needs to determine the difference in body size.
During the examination it is important to establish:
- the presence or absence of inflammatory processes in the genital area;
- ovarian size and density;
- gland consistency;
- the density of the walls of the uterus, its shape and size;
- condition of the cervical canal;
- color and condition of the vagina.
Only after the second examination is an accurate diagnosis established.
It is necessary to treat the corpus luteum in cattle
Most often, the prognosis of the disease is favorable. It is necessary to identify the cause of persistence and cure concomitant deviations in the sexual sphere, eliminate hormonal imbalance, and correct errors in the care, maintenance and feeding of the cow. Usually, after proper therapy, healthy calves are born.
How to treat corpus luteum in a cow
Immediately after confirmation of the diagnosis, therapeutic measures begin. The main goal of treatment is to increase the tone of the uterus and restore the basic functions of the genital organs:
- the cow needs to be allowed closer to the test bull more often in order to bring the female into heat;
- use hormonal medications according to a special regimen under the supervision of a veterinarian;
- Physiotherapeutic procedures are used, for example, ovarian massage, after which the corpus luteum comes out on its own after 4-5 days.
Sometimes they resort to surgery, removing the contents of the gland through the vagina or rectum. This operation does not require anesthesia or stitches, but can lead to some complications.
Veterinarians often squeeze out the contents of the corpus luteum. This is a simple procedure. First, the cow's intestines are cleaned of feces. Then the veterinarian carefully inserts his hand into the rectum and feels the ovary. Next, he grabs the gland and puts pressure on it. When its contents come out, the veterinarian clamps the cavity and holds it for about 5 minutes.This procedure does not interfere with the normal functioning of the ovary in the future.
During treatment, you should pay attention to the age of the cow. If she has had more than 15 calvings, she is considered old; there is no point in prescribing therapy at this age, despite the positive results of treatment.
Disease prevention
Since persistence of the corpus luteum is a common occurrence in cows, the owner needs to think about preventing the disease. First of all, you need to provide the animal with balanced feed, vitamin supplements, microelements, and arrange daily active exercise. The cow requires careful attention and special care during pregnancy, otherwise it will not be possible to avoid various complications during and after calving. Late passage of the placenta is also a cause of delayed corpus luteum, so a qualified specialist must be present at calving.
Conclusion
Corpus luteum in cows often leads to infertility. Therefore, the owner needs to diagnose the disease in a timely manner and promptly cure the animal for all inflammatory diseases of the reproductive system. Otherwise, it may lead to decreased productivity.
