Only 50% of dairy replacements making their way on to Irish farms are AI-bred. It’s a startling statistic as many people would consider AI to be one of the simplest and most effective ways of breeding better cows. So what’s involved?

Artificial Insemination (AI) is the process whereby cows are inseminated with sperm that came from a straw, as opposed to natural service from a bull. That’s the artificial part. The bull that produces the sperm is based at an AI stud and his ejaculates are collected and sorted into 6in long sealed straws which are then frozen in liquid nitrogen and distributed to AI technicians and farmers who do DIY AI.

When it comes to service time, the straw is removed from the liquid nitrogen flask where it is frozen at around -150°C and thawed in water at 38°C. The thawing process remobilises the frozen sperm and, all going well, one of the millions of perm in the straw will fertilise the egg and conception will occur.

The advantage of AI is that hundreds of thousands of cows can potentially be mated to the best bulls. Therefore, AI speeds up genetic gain. The alternative to AI is the stock bull.

The problem with him is that his genetic merit is low relative to what is available in AI studs.

AI is much better than natural service for genetic gain. \ Philip Doyle

If the bull was good enough he would be in AI so he is inferior. Furthermore, his reliability is low. So while his genetic merit is lower than AI bulls, his reliability is lower so there will be more fluctuation in his figures.

The other advantage of AI is that you are removing the animal effect. This refers to stock bulls not performing because they get lame, sick or infertile during the breeding season. An infertile stock bull affects a number of herds every year.

So if AI is the way to go, where do you start?

1 Decide what method you are going to use

There are two ways of doing AI, the first and most straightforward is to get a technician to carry out the AI. In this method, the technician comes to the farm and inseminates the cow for a fee, on top of the cost of the straw.

Indicative prices for insemination are around €18 and around €20 for a good AI straw.

Most companies have reduced technician fees for repeat serves. The second option involves DIY AI but this involves at least five full days of training and the purchase of your AI flask and liquid nitrogen. The training will cost around €500 and the flask will cost another €500, with annual liquid nitrogen costs of around €250.

2 Present the cow for AI

A healthy cow starts cycling around 30 days post-calving and is in heat every 21 days. For a cow to go in calf, a sperm must meet the egg at the time of ovulation, which occurs roughly 12 hours after the onset of standing heat. That said, the timing of conventional AI is not as critical as you might think, as correctly managed semen will survive in the uterus for up to 24 hours. The timing of sexed semen is more critical as it has a shorter lifespan in the cow.

3 Heat

Critical for presenting the cow for AI is identifying the cow that’s in heat. Heat detection is a huge part of AI and is probably the one thing that turns farmers away. There are a number of heat detection aids that make spotting the cow in heat much easier. These include:

  • Tail paint.
  • Scratch cards.
  • Kamars.
  • Crayons.
  • Automated activity monitors.
  • Without using some of these aids, the farmer will have no choice but to observe cows four or five times a day, which is very onerous and time-consuming. Using heat detection aids doesn’t overcome the need for observations, but greatly reduces the amount of observations needed.

  • Know the signs of heat. A cow standing to be mounted is the only true sign of heat, but most mounts only last for two or three seconds and a cow might only be mounted two or three times so the chances of seeing a mount are slim.
  • Tail paint is removed. Cows that have been in standing heat will have their tail paint removed or partly removed.
  • Heat mount detector (Kamar or scratch card) is triggered. These operate in the same way as tailpaint and are activated when the cow is mounted by other cows. They are probably more sensitive than tailpaint so some farmers will use these after the first few weeks are over when mounting activity decreases.
  • The cow attempts to mount other cows. Cows that are soliciting other cows are likely to be in heat or coming into heat, but this is not always the case. Other signs are sniffing the vulva or urine of other cows.
  • Tail paint is rubbed but not removed. This shows that the cow was mounted, but not mounted enough to rub off all of the paint. She could have been mounted by another cow that was in heat in the collecting yard so it is important to look at the other signs of heat.
  • The cow is restless or bellowing or acting out of character such as running on the farm roadway.
  • The cow has poor milk let-down. Some cows in heat don’t let down milk.
  • You see clear mucus around the vulva. This is a clear sign of heat but is unlikely to be noticed on its own.
  • You see mud marks on the flanks. The cow was probably mounted by another cow.
  • The heat mount detector is lost. It could have been knocked off during a mount, but it could also have just fallen off so you need to watch out for other signs.