Swinish artificial insemination

(*) Jodi Sterle and Tim Safranski, (Univ. of Missouri - Columbia - USA)

The artificial insemination in pigs is not a new technique. Reports are had, as old as of the decade of 1930, of the collection of semen for insemination. But the use of the artificial insemination has been shot in the United States during this last decade. It is important to remember that the artificial insemination is a tool that will only work in its operations if it manages it and it uses it correctly.

One of the disadvantages is that it can require a level of higher handling that in it mounts natural. For example, in the artificial insemination it exists bigger opportunity that they happen human errors that with it mounts it natural. When a hog mounts the female, the semen is not exposed to big environmental changes, and it is generally deposited in the female more than once, during one period that he/she understands the good moment for the fertilization. In contrast, it is possible that, while the semen is collected, it is diluted, it is transported and then he/she is deposited artificially, happen many environmental changes. The insemination should be made correctly and in the good moment. To obtain a discharge conception rate and numerous litters, the detection of the estro (checkup of the zeal) it should be made carefully and without flaws.

The hygiene of the team is very important in the whole process of artificial insemination. Today is possible to manage the semen using disposable materials, what avoids the task of cleaning the teams rigorously. When one makes a nice effort to consider and to incorporate these practices, the artificial insemination can work in any swinish operation.

Perhaps the biggest advantage that he/she offers the insemination is that it allows him bigger use of new superior genetics, at a cost potentially smaller that some of the systems of it mounts natural and with less risk of transmission of illnesses. To buy the semen allows genetic diversity that can be used to optimize the cruzamientos systems in the smallest farms and to increase the genetic progress. This you can achieve without the expense of to buy and to maintain a superior hog. Also, the good hogs can be used more extensively than those that are used for it mounts natural because with the IA you the number of inseminations increases had ejaculated.

The cycle swinish estrual

The cycle of the estro in pigs averages 21 days, but it can be among 17 to 25 days. The first day when the sow is receptive to the male and it is stopped to be mounted it is what we call "day zero". TO both or three days in that the female is sexually receptive she is called estro. The reflection of immobility is stimulated by the contact with a mature hog. The male's glands salivares submaxilares produce feromonas that are secreted with the saliva. The best form of assuring that those stimulating substances are transmitted to the female is the direct physical contact. The feromonas points out to the female that is present a mature male and they begin the reflection if the sow is in estro. The sow can or not to exhibit other visible signs, including to mount or to try to mount other females, red, inflamed vulvas, mucosities in the vulva, vocalization increase and of activity. In the lechonas, the estro can only last one or two days, but in the mature sows it can last three days. Although the ovulation (liberation of the ova of the follicles of the ovary) it generally happens from 23 to 48 hours after the initiation of the estro, this event is extremely variable. In fact, a sow can ovulate before it happens the estro. For this reason it is that the producers usually inseminate the females more than once.

Detecting the estro

The importance of the detection of the zeal in the system of IA should not be overestimated. It is absolutely vital for the success of each insemination that the producer is exact in the estimate of the beginning of the estro. It is more effective to detect the estro twice a day that a single time, apesar that he/she wastes away more time and manpower. The problem that is presented with the double daily detection is that benefits can only be obtained if both checkups are carried out correctly and separated approximately by 12 hours. The frequency of the detection of the estro will determine the accuracy of the estimate of its initiation. So that it is more efficient the detection should be made at first hour of the morning, before the feeding of the sows and at least one hour later. If this is not possible, the afternoon or the evening can serve, if the environmental temperature is not very high. The principle is to carry out the detection of the estro when the lechonas or the mature sows are not distracted or frustrated. The detection should be made in a neuter corral, with groups of 12 sows, or less. When transferring as much to the sows as to the male to a corral that is new for them, the detection of the estro is optimized. This is an aspect of the specially important estro in the lechonas. With the sows in gestation cages, a male should be exposed in the corridor, in front of four or five sows at the same time, so that they have individual contact, and to assure that the technician can observe to all the sows that are in estro before they begin to reject the male. You can apply manual pressure on the loin of the sows while they are in presence of the male to determine if they are in estro. The male will generally grunt, it will salivate and he will try to mount most of the females. A female in estro can look for the male and to be presented to be mounted. Once it is detected that a sow is in estro, it should be taken out of the corral so that the pig circulates among the other females.

It is critical to serve to the sow some hours before the ovulation. However, the moment of the ovulation varies. The lechonas will ovulate before the sows after the initiation of the estro. There are also variations among farms, genetic lines and females. As the sows they are presented during more time than the lechonas and as the ovulation in both sows and lechonas happens when concluding the estro, it is recommended that, with two daily checkups, be inseminated to the lechonas 12 hours after the detection the estro and to the sows mature 24 hours later. When you chequea solely once a day, it diminishes the accuracy of the determination of the estro and it is usually inseminated to mature sows and lechonas when they are in estro. When the expression outlines and duration of the estro settle down in a certain farm, it is possible define the moments and number of services again. Also, it is recommended to serve all the females once a day while they are presented. This can it is in certain I waste of semen, but it is the best form to make sure that at least a service was made in the good moment of the ovulation.

The reproductive system of the female

The reproductive system of the sows is lent to the IA better that that of the cows or the sheep, therefore, with the sows he/she wastes away less time and less manpower. However, to obtain good results they are required good technical and to understand the reproductive system of the sow well.

The vulva is the visible portion of the reproductive tract and it can be red and inflated before or to the moment of the zeal. The vulva leads to the vagina that he/she goes diminishing of diameter toward the cervix. This consists on multiple waves that act as barrier against bacterias, dirt and other strange matters. During the estro, the cervix swells, what allows that the pipette or catheter of IA you "he/she closes inside" (the pipette is the insemination bar, in a spiral way and with tip of plastic material and the catheter is the insemination bar with sponge tip).

This prevents that the semen goes back and the contractions of the uterus essentials begin to transport it through him until the oviduct, where the fertilization takes place. The ovary liberates the ova during the ovulation and these penetrate in the oviduct. In it mounts it natural, the penis of the hog (that has sacacorcho form) he/she puts on shoes with the pleats of the cervix and the pressure makes that the ejaculation begins. The semen travels for the uterus, helped by the uterine contractions that have begun for the presence of the penis in the cervix, and they penetrate in the oviduct, where they combine with the ova (fertilization). The recently ejaculated sperms are not able to penetrate in the ova and they should be present in the reproductive apparatus of the female of two at three hours to suffer the necessary biological changes for the fertilization. This is the process of training of the sperm.

Inseminating the female

It is good idea to evaluate the quality of the semen with a microscope before using it, since the transport, dilution, storage temperature, the fluctuations of temperature and the time lapsed from the collection, they can affect their useful life, motility and viability.

Use a paper towel to clean the vulva before proceeding to the insemination.

Lubricate the end of the pipette or of the catheter with some lubricant one that is not espermicida. Take care of not obstructing the hole of the instrument with the lubricant one.

Introduce the instrument carefully, with the tip up, for the vagina until the cervix. The bottle with the diluted semen has not still been connected with the pipeta/catéter. A reason of this is not to expose the bottle unnecessarily to excesses of light or temperature Maintaining the tip of the instrument up it minimizes the risk of entering in contact with the bladder.

When it uses a pipette, a rotation in the sense contrary to the needles of the clock he/she will make it penetrate in the cervix. In that moment he/she can feel certain resistance when taking of the pipette back. When a catheter is used with sponge tip, not always this inside the cervix. Instead of it, it can be against the same cervix. However, there are producers that push smoothly to try to insert the sponge tip inside the first ring of the cervix. If the tip this subject to the cervix, will feel resistance when broken the catheter.

Invest carefully two or three times the bottle that contains the semen diluted to mix it. Hold the bottle in the end of the pipette and discharge the semen slowly. It can be necessary to oppress the bottle lightly to begin the process, but later it should be let that the semen is extracted by the contractions of the uterus. Generally, this process lasts at least three minutes. Due to the variation of the intensity of the contractions of the uterus, it usually takes more time to inseminate to the lechonas that to the mature sows. If it is deposited very quick the semen can cause reflux for the vulva. Evidently that semen that you comes out is wasted. Remember that you are trying to replace the hog that spends from five to ten minutes in each it mounts.

It is of waiting that something of semen you comes out. If the quantity that you comes out is excessive, stop the operation. Or the semen is being deposited very quick (it will be necessary to deposit it more slowly) or the pipette is not inside the cervix. If the flow stops, place the pipette better rotating it a turn room to restart the flow of semen (if it is using catheter, move it slowly ahead and behind). Additionally, he/she can help if a hole opens up in the bottle with a punch or knife if it is that the flow stops to have been formed a hole.

If there is too much resistance to the flow of semen, place the pipette again, because it could be tight against one of the pleats of the cervix.

The transport of the semen, and therefore, the fertilization, it can be inefficient when the sow is afraid or it bothers; it is always necessary to calmly manage the females and softness. The inseminador is trying to imitate the hog, and the biggest fertility happens when it becomes well. Having present a hog, applying pressure on the loin of the sow and massaging her in the flanks during the insemination, the quantity and intensity of the contractions of the uterus can be increased that they extract the semen of the bottle and they transport it to the interior of the uterus. This is specially certain when it is inseminated to the lechonas. If the female too much time has been "closed" and expecting a lot of time to be mounted, you/he/she can reject the insemination. If this happens, it is necessary to take it out of the male's presence at least one hour and to prove again. It is important that the female begins her reflection of immobility while you/he/she is being inseminated; the uterine contractions are stimulated this way, vital for the transport of the semen.

When it has been deposited inside the female all the semen, extract the pipette making it rotate in the sense of the needles of the clock while it is pulled smoothly. There is who prefer to leave the catheter in position several minutes to prolong the cervical stimulation.

In each insemination a new pipeta/catéter should be used to eliminate the possibility to transmit infections from a female to another.

Maintain the female in a calm place for 20 to 30 minutes. Any restlessness in these moments can interrupt the transport of the semen and the fertilization.