Where will the next generation of AI sires come from?

How are we going to produce the next generation of AI sires?

This was a question posed by Donagh Berry to the audience at the recent Teagasc national dairy conference.

“This a big problem that the industry faces going forward and one that’s really starting to worry me,” he said.

The issue has emerged as a result of dairy farmers doing as advised and making the most of sexed semen technology.

Farmers have been selecting the best cows and heifers in their herd and breeding them with a sexed AI straw.

The remaining animals are then bred to beef bulls from AI or beef stock bulls to produce a better animal for future slaughter.

Conventional

Before sexed semen, dairy farmers were choosing their best cows and breeding them with a high-EBI conventional straw. As a result, the farmer ended up with 50% of the calves as high-EBI bull calves.

From there, AI companies would select the highest EBI bull calves born in a year from their sires and those calves would be put forward for genomic testing and potential future AI sires.

Through this process, there was a wide pool of bull calves to choose from and, therefore, a greater probability of finding better animals with less undesirable traits.

This is no longer the case and with fewer Irish bulls available and a smaller selection pool, the risk of inbreeding is much greater.

Future

To solve the problem, farmers would need to start breeding a small number of dairy bull calves again.

Everyone benefits from a good breeding programme, particularly the farmer, so it makes sense that farmers continue to contribute back to the programme.

Since the establishment of the Gene Ireland programme in 2005, in conjunction with the development of EBI, the rate of genetic gain in Irish herds has risen dramatically. This can be seen in Figure 1 below.

“What will it take for Irish farmers to start breeding some bulls again,” Donagh Berry asked on the day.

It’s an important question and one that will need to be addressed if we’re to continue achieving a high rate of genetic gain.

The answer is farmers with high-EBI animals will have to be willing to use some conventional semen in their breeding programme again.

Most of the AI companies out there are contacting a portion of their clients with high-genetic merit cows and asking them to use conventional semen on certain animals.

However, even at this, the number of dairy bull calves being bred is still too low, according to Donagh.

Before farmers commit to doing this though, it’s clear that advice will be needed on what the best bulls to use are.

High-EBI Irish bulls are the straightforward option, but may not be the right choice. As there are fewer bulls around, just selecting the high-EBI bulls could mean an increased risk of related matings.

Instead, out-cross bulls unrelated to the current population are likely to be more suitable, as it will reduce the chance of future inbreeding.

The fact that there hasn’t been a lot of communication on the issue up to now would suggest it’s not a major problem yet for the industry, but something that’s coming down the track.