Profitable Lifetime Index (£PLI) is the most important dairy cow trait for long-term fat and protein production, according to AHDB.

Research shows that the genetic indexes which have the most impact on average daily lifetime yield are £PLI, closely followed by fat (kg), lifespan and protein (kg). Other important traits include fertility, milk yield and health traits, such as mastitis, lameness and somatic cell count (SCC).

“Lifespan came out very strongly in the research, which is not surprising, as we are looking for animals which will live and provide milk for longer, so lifespan is vital for farmers looking to improve herd genetics,” said AHDB head of animal genetics, Marco Winters.

“But health traits are also clearly very important, because of course healthy animals are more likely to stay in the milking herd and produce strong yields.”

He already achieves very high daily milk yields, but he feels breeding for fat and protein is becoming more important

Dairy farmer Willie Baillie, who hosts AHDB’s Strategic Dairy Farm in Scotland, has recently made the decision to focus on improving the yield of fat and protein in the milk he produces.

He already achieves very high daily milk yields, but he feels breeding for fat and protein is becoming more important.

“At the moment, we are really focused on fat and protein percentages, because that’s one area our herd’s fairly low in. Probably because we’ve always been on a liquid milk contract and that wasn’t something you selected for in the past,” said Willie.

I don’t think it matters what system you are on, fertility can be the difference between profit and loss

“While we are still on a liquid milk contract, I do think these fat and protein traits will become more important to the whole industry, so we only select now for pluses in those areas and for fertility – because

“I don’t think it matters what system you are on, fertility can be the difference between profit and loss.”

Over the last few years, Willie has seen clear genetic gains through using this approach and his herd has moved from the top 20% to the top 15% of UK herds in terms of genetic merit, measured by the herd average for Profitable Lifetime Index (£PLI).