Basic rules for artificial insemination of cows
Artificial insemination of cows is one of the most common breeding methods. This method allows you to get healthy offspring, to accurately calculate the term of birth. This technique has a great advantage over natural fertilization.
Artificial insemination of cows
How to choose the right time
To carry out artificial insemination of cows, it is necessary to correctly choose the most optimal period for the meeting of the egg with the sperm. In order to determine the timing correctly, it is necessary to be guided by three factors.
- It is important to remember that the susceptibility to fertilization in a mature egg is only 5-10 hours. After this time, it ages and the risk of abnormal development of the embryo or its death increases. Accordingly, by the time of ovulation, the seed should already be in the genital tract.
- Before fertilization, the sperm goes through a preparatory stage - capacitation. This process takes 5-6 hours.
- After natural fertilization, sperm can retain their properties by being in the tubes for 24-48 hours. The vitality of frozen-thawed spermatozoa is much less and is approximately 12 hours, therefore, sperm must be injected 12 hours before a hypothetical ovulation.
All three of these provisions characterize the importance of accurately determining the timing of ovulation in heifers and seasoned cows. In female cattle, the stage of ovulation occurs during the period of inhibition, that is, it occurs at the end of the hunt, after 10-12 hours. It follows that, if estrus began in the morning, then artificial insemination begins in the evening, at about 17-19 o'clock, if estrus was recorded in the evening, then fertilization is carried out in the morning.
Artificial insemination in dairy cows should be carried out 2 hours before the start of milking or 2 hours after. During milking, the brain sends a signal and the uterine cervix does not work for suction, which significantly impairs the effectiveness of the insemination process. The second important rule that determines the success of an event is the multiplicity. Females are inseminated starting 2 times. First, the procedure is carried out after identifying signs of sexual heat, the second - after 10-12 hours, and if the hunt continues, then every 12 hours.
How to identify heatwave
The most accurate indicator by which you can determine the onset of sexual intercourse is estrus and arousal. At the moment, there are several ways to determine the readiness of the female's body for mating. The first way is visual. Animals become restless, looking for a male, a white-transparent liquid oozes from the labia, which becomes thicker and whiter by the end of the hunt. The disadvantage of this method is that the listed signs cannot be noted in animals with "quiet" hunting and in females with diseased limbs.
The second way of definition is reflexological. For this method, a probe bull is used, that is, they watch how the female will react to the presence of the male. The cow in the pore allows the bull to jump on itself. The method is rather imprecise, since the sampler is taken to the tied females, and often pregnant houses resignedly accept the bull, and young heifers reject him even during the hunt.
The third way is vaginal. Examination of the vagina with a mirror. During the hunting period, the mucous membrane will be swollen and reddened, and the fallopian tube is slightly open. Transparent mucus oozes from the fallopian tube, which accumulates in large quantities at the bottom of the vagina, then pours out through the external reproductive organs. The disadvantage of this method is the need to bind the animal, often in young females the opening of the uterine cervix is rather weak.
The rectal method involves examining the ovaries through the rectum. At the beginning of the hunt, the mature follicle is well palpated; when pressed, the movement of fluid is felt. An immature follicle will be a hard tubercle protruding slightly above the ovary. Of the disadvantages of the method, it is noted the need for frequent examinations, which can lead to damage to the follicle and the release of an egg from it. The hormonal method involves determining the amount of progesterone in plasma, milk or urine. Ultrasound is the most accurate method. The disadvantage is expensive equipment.
What is needed for insemination
Insemination requires not only certain skills and knowledge, but also the availability of equipment. Instruments must be prepared and disinfected in advance. The list of tools that the insemination station should be equipped with:
- thermostat;
- catheter;
- microscope;
- gloves;
- mirror;
- a bag that stores insemination instruments. Instructions for the technician-inseminator.
In addition to all this, you must have a large number of different reagents with you to determine the vitality of the semen. You will also need a considerable number of disinfectants. The station where cows are inseminated must be equipped with powerful lighting devices. Fully equipped insemination laboratories are available only on the territories of breeding farms, in other cases the technician works at home.
How to prepare a female for insemination
If insemination is carried out at home, the stall must be thoroughly cleaned. It is important to remember that in no case should harsh chemicals be used for cleaning. Potassium permanganate can be used to disinfect the room. The anus is manually cleaned of dirt, after which the technician finds the uterine opening and massage.
In the next step, the entire back is washed with warm water and baby soap. After washing, the washed areas are treated with furacilin. At the end of all these manipulations, you can proceed directly to insemination. You can watch a detailed video on preparing a female for artificial insemination.
How to cover a cow
Artificial insemination of cows requires knowledge of the characteristics of the structure of the genitourinary system in cattle. All insemination methods are based on three determining factors. Instruction on artificial insemination of cows is important information that every farmer should have.
- It is important to remember that in individuals with a vaginal type of insemination after fertilization, the cervix absorbs the semen and also acts as an intermediate reservoir. From the cervix, sperm are delivered in separate portions into the uterine cavity, respectively, in a single dose for insemination of cows there must be at least 10 million spermatozoa.
- During the natural process, more sperm enters the uterine cavity than during artificial insemination. Hence, it turns out that the entire dose should be injected directly into the uterine opening.
- After giving birth, the walls of the uterus are stretched in cows, which requires some experience and accurate knowledge of the location of the cervix.
Insemination
The above provisions determine the presence of several methods of artificial insemination of cows. The first method is epicervical. It is based on the introduction of the semen as close as possible to the uterine cervix. This method is used only for heifers. The likelihood of using this technique is due to the absence of stretch marks on the uterine walls. The female is fixed and a catheter with an ampoule at the end is inserted into the vagina; after emptying the ampoule, it is worth providing the animal with rest.
The manocervical method involves artificial insemination into the uterine canal with manual control of the location of the uterine opening. One limb is inserted into the vagina and a uterine massage is started, after which a catheter with an ampoule is taken with the other hand and, controlling the hole with the index finger, push it all the way. The seed from the ampoule is squeezed out and, taking out the hand, massage the clitoris to stimulate the suction process. The technique of artificial insemination of cows by any method requires special attention to this process, since massage movements in the clitoris area stimulate not only absorption, but also ovulation.
The visocervical method is fertilization with visual control of the uterine opening. Technique of the method: fixation of the female, insertion of a gynecological speculum into the vagina, insertion of a catheter with an ampoule. If it is necessary to artificially inseminate several females at once with the sperm of one bull, it is necessary to thoroughly disinfect the catheter after each animal. The disadvantage of this method is the risk of damage to the walls of the vagina by the mirror.
The rectocervical method is the process of introducing sperm into the vagina with control of the uterine opening through the rectum. Fertilization in this way is considered the most suitable option. The rectocervical method provides one-time control of the fallopian tube, accurate semen injection and massage of the clitoris. Technique: fixation, advancement of the catheter to the stop in the cervix, palpation and fixation of the cervix, introduction of fluid.
How to know if insemination was successful
After artificial insemination, it is equally important to correctly determine the success of the event. Today, the most common and accurate methods for determining pregnancy are:
- rectocervical;
- hormone;
- Ultrasound.
When using the first method, during the examination, one uterine horn will be clearly larger than the other with a loose consistency. The ovary, belonging to the horn of the fruit receptacle, is much larger than the second; the corpus luteum is clearly palpable in it. The fallopian tube is located closer to the pelvic inlet. The hormonal method is based on determining the level of progesterone to blood, urine or milk. It is mainly carried out in a laboratory setting. From the beginning of ovulation, a corpus luteum is formed in cattle, which synthesizes a hormone. With the onset of pregnancy, this gland does not degenerate, but develops. The highest concentration of the hormone in the blood is observed at 4 weeks of pregnancy, after which the level drops slightly.
One of the disadvantages of the method for determining the amount of the hormone in plasma is the significant variability of fluctuations in the level of progesterone in the blood of different individuals. In addition, a similar picture can be observed with persistence of the corpus luteum. An ultrasound is considered to be the best method for determining whether you are pregnant or not. The method allows you to see the embryo as early as 21 days. It is on this day that you can already clearly see the heartbeat of the embryo. The disadvantage of the study is the possibility of its use only in the early stages. It is used only up to 3 months of pregnancy, because later the embryo descends into the peritoneal cavity and leaves the working area of the sensors. The second drawback: the rather high price of the equipment.
Why Natural Breeding Is Rarely Used Among Livestock Breeders
Artificial insemination of cattle has been used since ancient times. For this, soft sponges were used, placed in the female's vagina before mating. Pastoralists tried, therefore, to inseminate several cows at once from one bull, but the sperm obtained by the barbaric method for the most part turned out to be inactive, so successful fertilization could be observed only in 40% of cases.
Later, with the emergence of a large number of sexually transmitted diseases of cattle, people began to improve the methods of artificial insemination of cows. At the moment, natural fertilization is used extremely rarely. Each semen dose from a proven inseminator guarantees healthy offspring. You can also watch a detailed video clip that will tell you step by step how to prepare and disinfect instruments, as well as what artificial insemination is.