Signposts for Northern dairy breeding

A lot of farmers in Northern Ireland will this week be getting sire catalogues and various information on AI bulls that are available for purchase this autumn. For some, selecting between sires can be a daunting task. It can be so challenging that some farmers get others to do it for them. That’s not a good idea. It’s easy to get blinded with science by someone with a vested interest and concede on principals. As a farmer, in order to counter this you need clear guidelines on what you want to see in a sire. If the sire proof doesn’t measure up, then you don’t need it.

In Northern Ireland, AI sires are ranked on PLI (Profitable Lifetime Index). This list can be downloaded from the AHDB website (www.dairy.adhb.org.uk).

The second task is to select within the list, depending on what criteria you want to improve. At the Dairylink meeting, the two criteria farmers around the table decided to select on were fertility index and milk solids. Crucially, farmers want to be selecting sires with at least 10 on the fertility index score. This essentially means any sires that don’t have a value greater than 10 on fertility index are not suitable for use. They also suggested that sires should have a predicted transmitting ability (PTA) deviation greater than 0.10% for protein. When you impose both these criteria on the list of 800 PLI sires, you reduce the listing right down to a small number of suitable sires.

Is milk volume important?

The farmers then had a look at the sires which came up on that list. Some of them were negative in terms of milk volume, so they began to question their strategy.

CAFRE specialists David Mackey and Aidan Cushnahan, along with Teagasc’s Joe Patton, were quick to suggest that it wasn’t the end of the world if farmers used sires that were negative for volume. One farmer then asked: “So if a sire’s predicted transmitting ability (PTA) for milk volume is -300kg, what would you expect a daughter of that sire to deliver?”

David Mackey explained: “The base heifer in the UK system is averaging 8,200l and if you scale that up to a mature herd average yield it exceeds 10,000l/lactation. Using a sire with a PTA that is -300kg of milk means you are taking down the yield potential of a daughter from that sire by about 600kg (300kg x2) but, that cow could still have the genetics to produce over 9,000kg as a mature cow.”

When you stand back and think about this, it’s very clear most Northern herds are producing, or have the genetics to produce, a lot more than they are actually delivering. So really, many herds don’t need more milk volume genetics. You can get more milk in other ways, such as more days in milk, better lifetime yield, etc. As Dairylink adviser Aidan Cushnahan suggested, the average PTA for milk of the Greenmount herd is -33kg, with many of the mature cows in the herd -150kg and more, yet they are averaging about 9,300l milk/ cow/ year with a corresponding fat and protein yield of 699kg/cow.

Aidan also advised that all dairy farmers who are using milk-recording as a management tool, should take this further and generate a herd genetic report for their cows. This is essential to help with sire selection.

What about milk solids?

Joe Patton said: “Any of the work we have done shows about 60% of the performance in a herd is due to breeding. I did a piece of work for a group in Banbridge two weeks ago and while the payment system in Northern Ireland is different, it still pays to breed for better fat and protein. Moving protein from 3.3% to 3.45% and fat from 3.6% to 4.2% is worth an extra 1.6p/l. That’s a nice milk price premium for no extra cost.”

Kevin McGrade is in phase one of Dairylink and is farming near Omagh, Co Tyrone. He was quick to interject with his experience: “Look, I have been selecting for fertility and better milk solids for the last 20 years. My protein has lifted from 3.12% to 3.6% and average fat has gone from 3.8% to 4.8%.

“While volume stayed flat for the first five years or so, when I went down this road it has gradually increased over time, as we have better fertility with more mature yields in the herd. Obviously it depends on the herd each farmer is working with, but as a rule I’d say most cows in Northern Ireland have enough volume, so a minus figure in a sire is not a big problem. The emphasis in sire selection needs to go on better fertility and better milk solids.”

Dairylink farmer Stephen Wallace added: “We are using sires like Praser, Directive and Commend because we want to improve fertility, protein and butterfat. PLI is not our only driver for selecting sires, but if you get good fertility and milk solids you won’t be bad on PLI.”

Adviser comment Aidan Cushnahan

Remember that the Northern Ireland average protein percentage is 3.29%, while the Dutch are now over 3.5%, on average. The Dutch average output is 8,200l, while the Northern average is just over 7,200l. The Dutch have been selecting on fat and protein for the last 30 years. Breeding does work – at least 60% of subsequent performance is in the breeding.

In brief