Deep Uterine Insemination

By 6th May 2015News.


Adapted from ‘A Short Guide to Successful Pig AI’ by David Kay

AI has become increasingly popular in the pig industry as it has a number of benefits over natural breeding. These can be summed up as follows:

  • Allows better genetics to be used throughout a herd, thereby improving performance
  • Cost effective use of boars – fewer needed to be kept on a unit, thus reducing feed and labour costs as well as freeing up pen space
  • Less boars on the unit improves health and safety for staff
  • Superior results to natural service – when done correctly!

To achieve the above, it is vital that attention is paid to all stages of the process and that it is carried out by well-trained staff, who take enough time to do a good job. Hygiene is of the utmost importance and the set-up must ensure that there are always enough boars to meet requirements, with spare capacity to account for sudden illness etc.

While the processes of collection, processing, timing and storage/transportation all have varying possible methods, with associated pros and cons (will discuss in a future article), the purpose of this article is to discuss insemination itself.


The main aim of insemination should be to deposit the precious semen dose as deep into the sow’s uterus as possible, to ensure minimal loss through leakage, back washing and the sow’s immune system. The sow’s cervix is actually designed to keep out infection, and therefore can be quite a hostile environment for the sperm cells to pass through, not to mention the effect it has of exhausting the sperm as they utilise their energy reserves travelling towards the uterus.

Below:  A simple ‘bung’ catheter – cheap and therefore popular – actually deposits the semen dose at the wrong side of the cervix and therefore allows most of the semen to leak back out of the sow’s vagina.


Catherter 1

Cobiporc have developed catheters which actually lock into the annular rings of the cervix, and have a disc at the back to prevent backwards leakage of semen. There are two designs, the Spiral Catheter, advised for sows; and the Soft Catheter, which works on the same principles but is kinder for use in gilts. Below: the Spiral (left) and Soft (right) Cobiporc Catheters in the cervix.

Cathetre 2 Catheter 3









Deep Uterine Insemination

In classic AI, 7 to 10% of sperm cells are actually lost crossing the cervix (Kerwood et al. 2003). To combat this, Cobiporc have designed the ‘Unic’ Range of Deep Uterine Catheters, which have the advantage of saving the sperm from having to swim through the hostile cervix. Available in ‘Spiral’ and ‘Soft’ design, as above, the Unic catheters are inserted into the cervix then left for around the time it takes to insert another 4-6 catheters, in effect allowing one operator to serve up to 6 sows at the same time, while the sows, who must be in the last stages of standing oestrus and fully stimulated, will have fully dilated so that the deep catheter can then be gently fed into the sow up to the black mark on the catheter, which indicates the correct position has been reached.


Catheter 4Left: Unic Spiral Catheter, fully inserted into the open cervix of the sow, will deposit semen at the junction of the uterine horns – increasing the chance of successful AI.

It is worth investing in some good serving stalls, ideally 75 inches long by 22 inches wide, to accommodate both sows and gilts. When using service stalls, it is also possible to further enhance the process of insemination by using ‘Kobiclips’ – strong plastic harnesses which simulate the pressure from the boar’s front legs during natural mating while also supporting the semen dose – by allowing the operator to inseminate several sows at one time, up to 30 sows/hour can be successfully served in this way.



Catheter5Right: The Kobiclip up close and in action. Kobiclips are only recommended for use in stalls as they are susceptible to damage from other sows jumping on the sow’s back.




Courtesy of Dr Sarah Vermont of Vetsonic 01653 695333 Vetsonic logo