The Importance of Heifer Inventory

The dairy industry continues to evolve.  The advent of sexed semen gave dairy farms the opportunity to greatly increase the odds of getting heifers from the genetically superior cows, therefore increasing overall heifer inventory in the herd.  Recently, dairy farms have diversified into the beef industry as cull cow and calf sales have been a welcome addition to the year’s cash flow.  Beef on dairy crosses have become more popular and have delivered a substantial economic boost to the dairy producer’s profits.

Both trends can be a great opportunity for the dairy industry but also have associated risks.   Some dairy farmers found themselves with an overabundance of replacement heifers when using too high a percentage of sexed semen versus conventional. This has put a strain on facilities with overcrowding and is a financial drain as those heifers mature.  More recently, the extremely high prices for crossbred calves have convinced people to breed more cows to beef and have created a shortage of replacements on some farms. Remember, that from the time a cow is bred to her calf entering the lactating barn, it will take about 3 years. Due to this, it is important for farmers to plan ahead.  Farmers should evaluate their replacement needs and plan their breeding program accordingly each year.

Many factors are involved in calculating the requirement for replacements.  A farm trying to grow herd size internally will have a different strategy versus an overcrowded farm attempting to limit growth.  Cull rates, reproductive management, and heifer management all have a direct influence on the number of heifers needed in a year.

A shortage of replacements can lead to empty stalls and decreased yearly production. Additionally, economically unproductive cows may not be culled to maintain cow numbers if there is not a genetically superior animal available to fill her spot. Having to purchase replacements produces an economic cost but also raises biosecurity issues.  It is possible for animals to develop illness after the stress of trucking, the introduction to a new facility, new cows, and a new diet.  Even more costly is the risk that apparently healthy purchased animals can introduce a disease into the home herd.  Both situations can lead to risk with loss of production, veterinary costs, and potential death loss.

Raising too many replacements also carries significant risks. On many farms, keeping an excess number of replacements results in overcrowding.  Overcrowding can lead to feed bunk competition, increased social stress, and increased demands on bedding and manure hauling.  With overcrowding, there are less aggressive animals that have a much lower rate of gain, delaying their entry into the lactating herd.

The overcrowding problem has many indirect impacts on the health of the animals.  Without an increase in management intensity, there is an increase in the manure accumulation that adds moisture and ammonia to the environment.  Dirty, wet animals have an increased demand for energy, especially in cold weather.  In addition, the manure contamination raises bacterial contamination on the skin. The combination of those factors can lead to a higher incidence of respiratory disease and lameness.

The major problem of raising too many heifers is the economic cost.  A 2000 Penn State study estimated the cost to raise heifers from birth to weaning to be $1124.06 (Gabler et al., 2000) From 2021-2023, members of the Penn State Extension Dairy Team completed a heifer research project where they followed 545 dairy heifers on 20 conventional and 20 organic dairy farms from birth through freshening. Heifer growth data was collected at birth, weaning, breeding age, and freshening. Individual farm financial data was also collected and analyzed along with the growth data to determine the farm’s individual costs to raise their heifers. For the conventional farms, the average costs to raise heifers through freshening was $2124 to $2304. However, there was a considerable range from $1424 to $3369 for all farms in the project. For organic dairies, the average was $2017 to $2220 with a range of $1064 to $3603. There are several factors that affected those wide cost ranges.  The biggest factors were increased age at first calving and   high purchased feed prices.

To help calculate how many heifers are necessary for your operation, Penn State Extension has a tool to help you determine how many heifers are needed on your farm. Farmers can input their specific farm data into the spreadsheet and get the number of heifers currently being produced on the farm vs how many are needed. This heifer inventory calculator can be accessed online

Raising heifers can be a strenuous task. Raising an unnecessary number of heifers can result in health risks, as well as financial strain on the dairy farm. Be sure that you know just how many heifers your farm needs to meet the specific goals of your business .

References:

Bach, Alex and Ahedo, Jose, Record Keeping and Economics of Dairy Heifers, Veterinary Clinics Food Animal Practice 24 (2008) 117-138.

Cummings, Daniel, Meyer, Nathan and Step, Douglas, Bovine Respiratory Disease Consideration in Young Dairy Calves, Veterinary Clinics Food Animal Practice 38 (2022) 93-105.

Gabler, M. T., Tozer, P. R., and Heinrichs A. J. Development of a Cost Analysis Spreadsheet for Calculating the Costs to Raise a Replacement Dairy Heifer. Journal of Dairy Science, 83 (5), (2000). 1104-1109. doi.org/10.3168/jds.S0022-0302(00)74975-7.

Grothe, James and Thornsberry R.M., Commercial Dairy Calf Management, Impact on Performance and Health. Veterinary Clinics Food Animal 38 (2022) 63-75.

Hoskins, Ann, 5 Decision Points for Culling Heifers, Ag Proud, Sept. 13, 2017, 5 decision points for culling heifers - Progressive Dairy | Ag Proud

Overton, M.W. and Dhuyvetter, K.C., Symposium Review: An Abundance of replacement heifers: What is the economic impact of raising more than are needed? Journal of Dairy Science 103:3828-.