The way a beef cow rears her calf has some advantages over the dairy system. A lactating beef cow has milk on tap — or on teat — 24/7, often provides more than the limit-fed dairy calf, provides constant socialization and more. Despite this, the beef system could learn from dairy — the world I work in — and change the outcome of a beef calf’s potential.
The Colostrum Imperative
Because colostrum is so crucial to a calf, dairy operations focus heavily on it. Colostrum provides passive immunity, growth factors for small intestine development and highly concentrated nutrition. In beef operations, ensuring the calf is nursing and the dam is accepting also is common, but it is often assumed that is sufficient.
Dairies and calf ranches will take a blood sample of calves from 24 hours to 3 days of age and test for IgG. IgG is the most important immunoglobulin a calf gets from colostrum — the one that most broadly prepares the calf with antibodies necessary to fight common pathogens. This process is testing passive transfer.
The luxury of testing each calf’s prepared immune status by blood draw is not something feasible in the beef herd. Ensuring the calf is suckling and the cow has good mothering and willingness to nurse is important, but leaves an elevated risk of a large percentage of calves NOT receiving the crucial adequate passive transfer or Failure of Transfer of Passive Immunity (FTPI).
What Are the Risks for Inadequate Passive Transfer?
- Quality of colostrum produced (highly dependent on cow status and nutrition)
- Delayed time to suckling (reduction in ability of calf to absorb antibodies)
- Volume of colostrum consumed (insufficient quantities of antibodies)
- Confined calving areas, highly stocked areas (more pathogens result in lower absorption, cow teats more likely to have high bacteria counts)
What Is the True Rate of Failure of Passive Transfer in Beef Calves?
The working assumption in beef operations has been that a nursing calf is a protected calf. The literature says otherwise. A comprehensive review in 2025 by Abdelfattah, Fausak and Maier analyzing 63 published studies revealed 5.8% to 34.5% of beef calves suffer from failure of passive transfer. Calves with poor vigor or a sluggish suckle reflex were at the highest risk.
How Does Reduced/Failed Passive Transfer Affect Calves?
Both beef and dairy calf studies repeatedly show that the lower the passive transfer of antibodies from colostrum, the following is possible:
- Higher likelihood of death
- Higher likelihood of illnesses and antibiotic treatment (diarrhea and bovine respiratory disease (BRD) highly prevalent)
- Possibility for these events to affect average daily gain
The Critical Four-Hour Window
The same study indicates feeding a colostrum replacer versus suckling did not result in measurable differences in passive transfer or health outcomes. What most mattered was timing of colostrum — racing the gut closure happening from birth to get antibodies simply into the calf.
Four hours appeared to be the timeframe after birth important to target — if sufficient colostrum was consumed before four hours of life, optimal passive transfer was more likely achieved and decreased the likelihood of receiving treatment for diarrhea or BRD.
Practical Solutions for the Pasture
The practicality of animals consistently watched round the clock and ensuring adequate nursing volume and calf vigor is not always achievable or possible in a pasture setting. Utilizing a hyperimmunized antibody product, validated by the USDA, is a valuable tool to deliver key components of the most important meal of a calf’s life.
With the treatment costs and lost gain that come with scours, prevention pays. Hyperimmunized bovine colostrum raises concentrations of specific antibodies, and high antibody concentrations are essential for successful passive transfer. But what those antibodies target matters just as much.
Being specific in the antibodies provided for E. coli, coronavirus and rotavirus, as well as the development factors crucial in colostrum, becomes an important tool to ensure each calf gets the protection desired regardless of vigor, suckling behavior, consumption amount, and timing. It reduces variability and increases the likelihood of positive health of the upcoming, extremely valuable, calf crop.
Dairy calf-rearing systems offer a valuable insight to cow-calf producers: viewing each calf not as an assumed certainty, but as a biologically variable animal creates a major opportunity to prevent disease.
A dairy system may be able to adjust systems as they calve year-round, changing volume of colostrum, time fed, etc. Beef systems may not have those adjustments available, yet benefit from understanding the variability that exists within every operation, and approach calving season with extra concentration on the first few hours of each calf’s life.
Protocol Comparison: Dairy vs. Beef Management
| Process | Dairy | Beef |
| Colostrum timing and amount | Offer or tube feed colostrum that is tested for concentration to each calf within a certain time frame of birth | Observe calf is drinking, dam is accepting. Watching for full belly, vigor. |
| Confirmation of colostrum performance (passive transfer) | Measure blood serum IgG of the calf 24 hours of age – 3 days | Usually none |
| Constant monitoring of year round calving outcomes in calves | Constantly happening | One or two chances to evaluate yearly, after calves have arrived post calving season |
— Rebekah Mathews has worked across both sectors — studying ruminant production and economics in undergrad, followed by dairy gastrointestinal development in graduate school. Today she serves as the Midwest region sales and marketing manager for First Defense.
