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Raising replacements right: The right number, the right way

David Baker and Donna Benschop for Progressive Dairyman Published on 28 February 2019

Today, many producers are looking to reduce costs and improve profits on their operations. An area often overlooked is the cost of raising replacement heifers.

Heifer-rearing costs amount to approximately 15 percent of total farm expenses or an average of $2,000 to $2,500 per heifer, bearing in mind both values can vary widely among farms.



While it is certainly a good exercise to determine what it costs to raise a heifer to calving on your own operation, in many cases another starting point is to determine how many heifers you need to raise based on your herd turnover rate (Table 1).

Number of replacement heifers required  for a 100-cow herd

Compare that number to how many heifers are in the barn. You might be surprised by the difference.

Most Canadian farms have more heifers than they need to maintain their milking herd size. Raising more heifers than needed can be a major drain on profits if money is being spent where there is no return.

Remember, in general, a heifer doesn’t become profitable until the second lactation, therefore it raises some important questions operators need to answer for themselves.


  • What is the most profitable group of cows in your operation? Does it make “cents” to replace a healthy, productive mature cow with a fresh heifer? (The answer is “no.”)

  • Will current fresh heifer prices allow you to make a profit if you decide to sell after freshening?

  • If herd turnover rate is greater than 35 percent, or age at first calving is greater than 24 months, are there additional bottlenecks on the farm that need to be addressed in order to reduce the number of replacement heifers needed?

  • For your own operation, when is the best time to make culling decisions for heifers, and what culling criteria will you use?

For every operation the answers might be slightly different, but of greatest importance is to have the discussion and develop a plan.

Alongside determining how many heifers you really need to raise is an understanding of how daily care and management of these replacement heifers will impact future longevity and profitability.

Achieving the lowest heifer input costs does not always result in the highest profits if health and growth rates are jeopardized. The most efficient farms in regard to raising heifers are those that consistently have an age at first calving between 22 to 24 months, with milk production greater than 85 percent of the milk yield of the mature cows.

We will discuss four key areas where proper management can improve the bottom line of the dairy farm.

1. Liquid gold

Colostrum remains the most important feed your calf will get to determine its health, growth and productivity. Current studies show colostrum is more than just antibodies and a high caloric content. It also contains growth promotion factors and hormones that work to assist in dry matter intake (DMI) and growth in young calves.

The study of epigenetics is pointing to early programing in the calf that will impact its potential for milk yield. Specific ingredients in the dam’s milk can turn on the gene expression in these calves that will genetically make them superior producers. According to Dr. Alex Bach, the freeze-drying of colostrum diminishes this benefit.


2. Average daily gain

In comparison to many other animal agriculture industries, monitoring gains in dairy replacement heifers is not a common occurrence. However, based on the solid research that clearly shows a strong relationship between average daily gain (ADG) and future performance, it is something we should be giving much closer attention.

Calves that grow well pre-weaning have been shown to be superior producers. First-calf heifers produced 1,000 kilograms more milk for every 1 kilogram ADG pre-weaning.

To put it on a more understandable basis, calves that grow at 0.9 kilogram per day will produce 100 kilograms more milk in their first lactation than calves that grow at 0.8 kilogram per day.

In fact, a long-term study out of Cornell University showed the enhanced ADG pre-weaning resulted in an additional 2,278 kilograms of milk over three lactations. Therefore, it is safe to say the impact of nutrition in the first eight weeks of life is far greater than any impact of genetic selection for production.

Note, the gold standard for ADG is heifer calves that double their birthweight in the first eight weeks of life (corresponding to 0.9 kilogram ADG).

Between the ages of zero and 6 months, heifers are the most efficient at converting feed into growth. While the costs of milk replacer, quality calf starter and heifer growers may be high, this is the time period when you get the best return on your investment.

Well-fed calves not only grow better, they are also healthier. This not only reduces veterinary expenses but allows for continued growth, earlier breeding and increased productivity. Calves never get over a good start.

3. Calf health goals

Health challenges in the form of scours and respiratory diseases can significantly impact ADG and future profitability of replacements. If calf mortality exceeds 5 percent, and calf morbidity exceeds 10 percent, there is a huge amount of money being lost both in the short and long term.

Calves that experience two or more episodes of respiratory illness (or even one bad episode) have permanent lung damage, which will decrease ADG in the short term and milk production potential in the long term.

These heifers should be marked for early culling to reduce the overall cost of heifer rearing. Calves that have significant scouring episodes will also experience reduced growth and production.

Any heifer that has experienced significant health challenges should be removed from the herd, as these animals will be late to reach breeding size, late to enter the milk herd and be less profitable than healthy herdmates.

4. Age at first calving

Data continues to show an age at first calving between 22 and 24 months is most profitable. Achieving an ADG of 0.9 kilogram per day will ensure heifers are the correct weight and height at breeding age, but good recordkeeping and standard on-farm protocols are the only way to ensure heifers get bred at the right time.

Monitoring heifer conception data can provide a lot of insight into how effectively on-farm strategies are being deployed.

Figures 1 and 2 show the age at conception for heifers over a six-month period of time on two different farms.

Heifer conception distribution by month of age

Heifer conception distribution by month of age

Identifying those heifers bred much too late can be another culling criterion, since their lifetime profitability will be lower.

Not only will maintaining a tighter window for age of conception (and therefore age at first calving) reduce the number of replacement heifers needed, it will also significantly reduce heifer-raising costs, making it a win-win situation.

Every dairy operation wants to be in a position where culling of heifers is based on a strategy that complements on-farm goals and plans. The use of genetic testing or looking at parental averages can be used as tools to pinpoint the genetically superior heifers in the barn.

However, these results alone will only tell part of the story. How heifers are raised, especially in the first eight weeks of life, is another telling factor in which replacements will be best to fill the herd in the future.  end mark

Donna Benschop is a Canadian ruminant technical support specialist with Cargill/Purina.

References omitted but are available upon request. Click here to email an editor.

David Baker
  • David Baker

  • Ruminant Technical Support
  • Cargill/Purina

Key take-home points

  • Colostrum intake is critical, not only for immunity but also for improved feed efficiency and milk yield

  • The impact of nutrition in the first eight weeks of life will influence future milk yield more than genetic selection

  • Aim for a minimum ADG of 0.9 kilogram per day; measure frequently to avoid any breakdowns in the heifer-raising process

  • Consider culling early to better control heifer-raising costs