It’s no secret that dairy heifers are in short supply, and their prices are high.
An early 2025 USDA-estimated inventory of just 3.914 million head of dairy heifers over 500 pounds marks the lowest population of dairy heifers in the U.S. since 1978. Meanwhile, the U.S. beef cattle herd is the smallest it has been in 64 years, ramping up incentives for dairies to produce more high-value beef-cross calves.
The financial upshot: today it is common for Holstein springers to fetch record-shattering values of $4,000 per head or more. That makes it challenging for dairies to grow or maintain herd size affordably. Or does it?
Surprisingly, dairy herd size has actually grown by about 114,000 head in the last year – to a current population of 9.410 million head -- through the recent heifer shortage and price-a-palooza. And May 2025 year-over-year milk production was up 1.56%.
That means stalls are being filled by the elder stateswomen of dairies. Higher-parity cows that may have been replaced by their first-lactation counterparts a few years ago are now likely being retained longer. And that’s largely for the best, according to Ryan Leiterman, DVM, Director of Technical Services at Crystal Creek Natural LLC, Spooner, Wis.
“Until recently, many dairies were milking 35% of their herd as first-lactation heifers, and some were even milking 50% heifers,” shared Leiterman. “These heifers are not even at their mature bodyweight yet, and they lack experience in the milking string.”
Leiterman said older cows can be an asset for the following reasons:
- They’re better producers – Cows typically hit their peak milk production in their third or fourth lactation. Statistically second-calf cows out-pace first-calf heifers by about 10 lb./cow/day, and third-and-great lactation cows outproduce second-calf cows by an additional 10 lb./cow/day.
- Milking them is easier – Multiparous cows, especially those in their fourth lactation and beyond, have more developed mammary tissue and better milk letdown.
- They know the drill – Older cows are better adapted to the specific conditions of the farm, such as milking schedules and environmental stressors. While first-calf heifers require training and are often more challenging to milk and manage, older cows have the routines down.
Still, the veterinarian acknowledged that higher-parity cows do come with problems. To maintain an older cow population, Leiterman said a dairy needs to be on top of its nutrition and management game to prevent early herd removal or altered production due to ketosis, milk fever, mastitis, lameness, and poor reproductive efficiency.
But by caring fastidiously for those older cows, Leiterman said dairies can amortize the cost of rearing replacement heifers – which now may exceed $2,500 per head – over more years of productive life. They also may require fewer heifers, so they can capitalize on beef-cross calf sales, or sell their excess heifers at a healthy profit.
Or plain old internal herd growth, without the need to purchase replacements for herd expansion, is another potential benefit. In any case, it’s rarely wrong to strive to keep productive cows in the herd as long as possible.
“While a farm with good cow longevity is not guaranteed to be profitable, a farm with short longevity due to a high involuntary culling rate is not likely to be profitable,” Leiterman stated.
