How Many Heifers? - October 2018

Based on a survey last year in Wisconsin, it takes about $2,100 to raise a heifer. With today’s market, it seems worth-while to discuss how to calculate the number of replacement heifers needed to maintain a herd. The calculation is based on the following:

- Total Cows (lactating and dry) = 1.16 x # of lactating cows

- Cull Cow Rate = 33% or less (industry standard)

- Heifer Cull Rate = 15% or less (industry standard)

Estimated Replacements = [Total Cows] x [Cow Cull Rate] x 1.15

The number of replacement heifers to maintain a current herd size is found by first multiplying the Total Cows by the Cull Cow Rate. Take 15% (Heifer Cull Rate) of that answer and add it back on, to account for heifers lost due to infertility, death loss, etc. The result is roughly the number of heifers that need to calve each year at around 22-24 months of age. If they’re older at calving, more heifers are needed.

For example: a herd of 100 cows with a 33% cull rate and 15% heifer cull rate needs a minimum of 33 heifers calving each year (100 cows x 33%). With a 15% heifer loss, we need an additional 15% of heifers to calve (33 heifers + (33 x 15%)), which comes to 38 heifers calving yearly to maintain a herd of 100 cows.

To continue the example, with only 38 heifers needed each year, there will actually be more heifer calves being born than need to calve. Since selling heifers as springers may not be profitable, consider strategically breeding the best cows to get the number of heifers needed and breed the not-as-good cows to beef. Additionally, knowing how many heifers to raise will help in culling decisions for a chronically sick heifer.

When considering the cost of raising heifers, there are many contributing factors, but the place to start is by knowing how many you need.