Preventing Calf Diarrhea Requires Going the Extra Mile

Rearing replacement heifers is an important step in dairy farming, as these young animals represent the fuel that keeps the farm productive. Raising calves is costly, so keeping them healthy helps avoid losses associated with treatment costs, mortality, and reduced productivity. Neonatal calf diarrhea, commonly known as scours, is the leading cause of mortality in preweaned calves (NAHMS, 2021). Affected calves often present diarrhea, dehydration, reduced feed intake, poor weight gain, and metabolic acidosis. Research shows that calf diarrhea has long-term effects, including decreased milk production in the first lactation and delayed age at first calving (Aghakeshmiri et al., 2017). Therefore, preventing calf diarrhea outbreaks is crucial to keeping your herd healthy, the farm productive, and profit margins high.

Evaluating colostrum management is the first step

Providing high-quality maternal colostrum or a colostrum replacer is one of the most important steps in preventing diseases in newborn calves. Calves are born without antibodies, which makes them highly susceptible to infection during the first weeks of life. Colostrum, the first milk produced by the cow before calving, is rich in antibodies, immune factors, and nutrients that protect and nourish the newborn calf. A successful colostrum management depends on three main points:

1. Colostrum quality and quantity

Calves must receive 3-4 quarts of high-quality colostrum (approximately 10% of birth weight). When possible, offering a second feeding 5 to 6 hours later may further benefit calf health (Abuelo et al., 2021). High-quality colostrum should contain at least 50 mg/mL of IgG, the main type of antibody in colostrum. This can be assessed on the farm with a colostrometer (green mark = ≥ 50 mg/mL when colostrum is at room temperature) or a Brix refractometer (≥ 22%) (Lopez and Heinrichs, 2022).

2. Timing of first colostrum feeding

The calf’s ability to absorb antibodies from colostrum declines rapidly after birth, and completely ceases after 24 hours of life. Ideally, calves should be fed colostrum within 2 hours of life, but if this is not always possible, ensure they receive sufficient high-quality colostrum within 6-8 hours (Lopez and Heinrichs, 2022). The rule of thumb is "the sooner, the better".

3. Cleanliness

Collection of colostrum must be performed following strict hygiene practices, as bacterial contamination can reduce colostrum quality and put calves at risk of infections. Bacteria thrive in colostrum, especially at room temperature (68-77°F). For this reason, colostrum that is not used within 2 hours of collection should be refrigerated or frozen, preferably in small-volume containers. Large containers, such as 4-QT bottles, should be avoided because they cool more slowly, facilitating bacterial growth. All collection and feeding equipment, including bottles, nipples, buckets, and esophageal tubes, must be thoroughly cleaned and disinfected after each feeding. Refrigerated colostrum can generally be stored for up to 3 days, while frozen colostrum can be stored for up to 6 months. Although stabilizers, such as potassium sorbate, can extend the shelf life of colostrum in the refrigerator, they will not be effective if colostrum is already highly contaminated.

The calves will tell you when your protocol is successful

 Evaluating colostrum management is important for identifying potential gaps in the protocol. For many decades, colostrum management was considered successful when calves had serum IgG values of > 10 mg/mL at 1-7 days of life. Although this threshold indicates adequate transfer of antibodies, research has shown that calves with higher serum IgG values, such as > 18.0 mg/mL, have lower mortality rates and lower risk of disease in the preweaning period (Lombard et al., 2020). Achieving higher serum IgG values across a large proportion of the herd is both feasible and beneficial when colostrum management practices are optimized. The current recommendations are summarized in the table below. However, keep in mind that dehydrated calves can exhibit elevated serum IgG values, which can falsely indicate successful antibody transfer.

Lombard et al., 2020. Journal of Dairy Science. ¹National Animal Health Monitoring System (NAHMS).

Even the best colostrum management cannot overcome poor sanitation

Although providing high-quality colostrum is key to raising a healthy and productive herd, colostrum alone cannot fully protect calves against disease. Effective cleaning and disinfection protocols and biosecurity practices need to be in place to reduce pathogen exposure. Any area or equipment that comes into contact with calves needs to be routinely cleaned and disinfected, including maternity pens, calf housing, and feeding equipment.

Feeding equipment, such as bottles, nipples, esophageal feeders, and buckets, needs to be cleaned and disinfected after each use using appropriate detergents and disinfectants. Pens, calf hutches, boxes, and flooring should be cleaned between calves. Because calf diarrhea can be caused by several bacteria, viruses, and parasites, cleaning and disinfection procedures need to be tailored to the most prevalent pathogens on the farm. Work with your veterinarian to develop protocols that fit your operation.

Biosecurity protocols should be established to prevent the introduction and transmission of disease among calves. Sick calves should be handled separately from healthy ones, and sharing equipment should be avoided. Preferably, staff should care for healthy calves before handling sick calves to reduce the risk of disease spreading. If handling sick calves first cannot be avoided, it is crucial to wash and disinfect hands, boots and equipment before working with healthy animals.

Preventing calf diarrhea requires going the extra mile with colostrum management, proper sanitation, and biosecurity practices. Attention to these details early in life not only improves calf survival and growth but also supports the long-term productivity and profitability of your dairy farm.

References

Abuelo, A., F. Cullens, A. Hanes, and J.L. Brester. 2021. Impact of 2 versus 1 colostrum meals on failure of transfer of passive immunity, pre-weaning morbidity and mortality, and performance of dairy calves in a large dairy herd. Animals 11:1–12. doi.org/10.3390/ani11030782.

Aghakeshmiri, F., M. Azizzadeh, N. Farzaneh, and M. Gorjidooz. 2017. Effects of neonatal diarrhea and other conditions on subsequent productive and reproductive performance of heifer calves. Vet. Res. Commun. 41:107–112. doi.org/10.1007/s11259-017-9678-9.

Lombard, J., N. Urie, F. Garry, S. Godden, J. Quigley, T. Earleywine, S. McGuirk, D. Moore, M. Branan, M. Chamorro, G. Smith, C. Shivley, D. Catherman, D. Haines, A.J. Heinrichs, R. James, J. Maas, and K. Sterner. 2020. Consensus recommendations on calf- and herd-level passive immunity in dairy calves in the United States. J. Dairy Sci. 103:7611–7624. doi.org/10.3168/jds.2019-17955.

Lopez, A.J., and A.J. Heinrichs. 2022. Invited review: The importance of colostrum in the newborn dairy calf. J. Dairy Sci. 105:2733–2749. doi.org/10.3168/jds.2020-20114.

NAHMS. 2021. Morbidity and Mortality in U.S. Preweaned Dairy Heifer Calves: NAHMS Dairy 2014 Study Calf Component.

This article was originally published and edited in Lancaster Farming on May 27th, 2026.