Dairy heifer numbers falling globally

The number of female dairy heifer calves born so far this year is back 12.1% on 2024 and is back 15.4% on 2023 levels. This is a staggering decrease in the number of dairy animals that are eligible to become first calving heifers in two years’ time.

At 292,337 dairy heifer calves born up to 1 April, that represents a potential replacement rate of just 18% based on a total dairy cow population of 1.6m cows.

Of course, between mortality and infertility at least 3% of the 292,337 dairy heifers born this year won’t calve down in two years’ time giving a more realistic replacement rate of around 17.7%.

These alarming statistics indicate that rather than growing, the national dairy herd is set to shrink.

In fact this is already happening as the number of animals calving down for the first time this year is back 10.3% compared to 2024.

A reduction in the number of dairy replacements is a phenomenon not confined to Ireland.

The latest figures from the Netherlands suggests that dairy heifer numbers are back 6.5% in December 2024 compared to December 2023, with cow numbers back 2% in the same period.

It’s a similar situation in Germany with dairy cow numbers falling by 3.3% in December 2024 compared to December 2023.

Further reductions are expected in 2025. In the United States, the most recent census of livestock showed that the number of dairy heifers is at the lowest level since 1978.

One of the main reasons for the reduction in the supply of dairy replacements in Europe and North America is the increased use of sexed semen. This may seem counter intuitive, but with sexed semen farmers are much more selective about what cows get bred to dairy as they are much more certain about getting sufficient replacement heifers to meet their own requirements.

Conception rates to sexed semen are lower than with conventional semen, but not by much when it is used correctly. In my view, it is the combination of less cows being bred to dairy and more cows being bred to beef that is resulting in less dairy replacements being born, both in Ireland and overseas.

Before sexed semen became popular, many farmers used to breed all cows to dairy for six weeks and do one round of dairy AI on replacement heifers. This was the traditional approach up to a few years ago.

Some of the reason for this was due to poorer herd fertility, where a 25% replacement rate was required. Another reason was that when herds were expanding, more heifers were needed.

Whereas now, many of the same farmers are using one round of sexed semen on heifers and using one round of sexed semen on perhaps half of the cows.

The result is sufficient replacements for their own needs to maintain herd size, but no surplus heifers for sale.

Part of this has been driven by the tightening of nitrates derogation rules where keeping surplus stock is just not an option.

In many ways Ireland has been an outlier in terms of dairy beef calf prices.

Prices for beef calves from the dairy herd have been 50% to 60% higher in the Netherlands, Denmark, Germany and Britain over the last number of years and that is still the case now.

It is only in 2025 that Irish calf prices have caught up to where the European prices have been. Meanwhile, prices for beef calves across Europe continue to be higher than the Irish prices.

In the Netherlands this week our sources say that two-week old Holstein Friesian calves are making over €430 excluding VAT while Belgian Blue calves at two weeks of age are making over €650 excluding VAT.

So while calf prices are higher than they have been in Ireland, they remain low by European standards.

Sexed semen is enabling farmers in Ireland and globally to increase the value of their calf crop by allowing them to use more beef breeds across their dairy cows.

However, this has come at the expense of dairy heifers and as we can see, there is now a shortage of dairy heifers in Europe and North America.

Alongside reduced supply of dairy heifers, there is also increased demand for dairy heifers in Ireland, Europe and the US. The main factor driving the increased demand is not expansion but animal health problems.

Highly pathogenic avian influenza or bird flu is rampant across the United States. Affected dairy herds experience sick cows, a reduction in milk yield of about 25% during the infection and increased mortality and infertility among infected cows.

While pharmaceutical companies are scrambling to develop vaccines, the impact of bird flu across the US dairy and poultry sectors is likely to remain a growing issue throughout 2025 and beyond.

The issue in Europe is Bluetongue disease and this is causing huge problems in affected herds throughout the Netherlands, Germany and northern France. Like bird flu, it causes animals to be sick, off their feed, and for milk yield to drop significantly.

According to recent reports, the fertility of dairy cows affected by Bluetongue goes below 50% and 30% of cows in affected herds end up empty.

According to our sources in the Netherlands farmers there are now experiencing a six-week break in calving because cows did not go in-calf for a six-week period last summer, due to Bluetonge.

While this is potentially one of the reasons for the increase in beef calf prices, as there are less calves available to purchase, it is also having an impact on milk supply.

While Bluetongue has so far avoided Ireland, there are growing fears that it could enter, especially if weather conditions are favourable for the midge borne virus.

The highest risk time will be summer and autumn when the midge is most active.

The disease causing most issues in Ireland is TB. There were over 41,000 reactors in Ireland in 2024, a 44% increase on 2023 levels.

Based on previous years, if 65% of all reactors are dairy cows that is over 27,000 cows leaving the system because of TB, which is about 1.7% of the national dairy herd – an enormously high figure.

There are two ways of looking at this for Irish dairy farmers.

On the one hand, the argument could be made that there could be a business case to produce and rear additional high EBI female calves for subsequent sale.

On the other hand, farmers that produce only barely enough replacements for their own use are taking a big risk with their business.

If in the unfortunate event of a TB or Bluetongue outbreak, sourcing additional dairy replacements of any EBI, never mind high EBI may not be possible.

As we are seeing at dispersal sales the value of dairy stock has shot up, with anecdotal evidence that many of the buyers of these cows are farmers that are re-building herds that were depopulated with TB.

Furthermore, from speaking to some of the AI companies there is increased demand this year for beef AI among dairy farmers, at the expense of both sexed and conventional dairy AI.

This indicates that the shortage of dairy heifers is likely to worsen in 2026.

Producing high value beef calves is all well and good, but the core business is producing milk.

Ensuring enough replacements should be a non-negotiable on dairy farms.

In brief