Can Extended Colostrum Feeding Benefit Calf Health and Growth?
Extended colostrum feeding is the practice of feeding calves colostrum or transition milk (2nd-6th milkings) beyond the first day of life, when calves can no longer absorb maternal antibodies into their bloodstream. Colostrum, the first milk produced by the cow before calving, is packed with maternal antibodies that protect calves against disease in the first weeks of life. Feeding colostrum soon after birth is critical because antibody absorption significantly declines 12 hours after birth and completely ceases after 24 hours. Therefore, calves should receive a sufficient quantity (~10% of the calf’s body weight) of high-quality colostrum (≥ 50 mg of IgG/mL; 22% Brix) within 2-6 hours postpartum to ensure proper transfer of passive immunity (from dam to calf).
But colostrum provides more than just antibodies to calves, which is the main reason behind extending colostrum feeding protocols. Compared to whole milk, colostrum contains more protein and fats, which support calves in the first days of life when their energy reserves are limited. It also contains several beneficial compounds that support immune function, gut development, and establishment of a healthy gut microbiota, which can boost calf health, growth, and future productivity.
Some of the main bioactive components in colostrum include:
Antibodies (IgG, IgA and IgM):maternal antibodies critical for calves in the first weeks of life. IgG represents 85-90% of the antibodies in colostrum. Although antibodies can only be absorbed in the first hours of life, some can still provide protection within the gut.
Leucocytes and cytokines:these are immune cells and proteins that can help calves fight pathogens in the first weeks of life. They also support the development of the calf's own immune system.
Antimicrobial factors: natural antimicrobial compounds, including lactoferrin and lactoperoxidase, that help inhibit the growth of harmful microorganisms in the gut.
Growth factors (IGFs, TGFs, Insulin): molecules that stimulate intestinal development, improving the calf's capacity to absorb nutrients needed for maintenance and growth.
Oligosaccharides: carbohydrates that can help develop a healthy intestinal microbiota. Gut microbes support digestion, immune development, and confer protection against pathogens.
After the first milking, the composition of colostrum changes significantly, and the concentration of beneficial compounds gradually decreases, reaching levels of normal milk after the 6th milking. Milk produced during this transition period is known as transition milk and can also be used for supplemental feedings.
What does research show?
Because of its unique composition, researchers have been investigating whether feeding colostrum or transition milk beyond the first day of life can improve calf health and performance (Renaud and Steele, 2024). Most studies have evaluated supplemental feeding for 3-14 days of life, at several levels of supplementation. For example:
- Colostrum or colostrum replacer (CR);
- Transition milk (2nd-6th milkings);
- 1:1 inclusion: colostrum/CR + whole milk/milk replacer, mimicking transition milk;
- Whole milk/milk replacer supplemented with 10-20% colostrum or colostrum replacer
Several studies have shown that feeding colostrum or transition milk during 3-4 days after birth improves intestinal development compared to calves that do not receive supplemental feedings (Renaud and Steele, 2024). The intestines are responsible for absorbing nutrients, water, and energy from the diet, and improving absorptive capacity can result in better productivity outcomes. For instance, a study from Michigan State University showed that calves fed transition milk for 3 days weighed approximately 6.6 lb more at 56 days of age than calves fed milk replacer (Van Soest et al., 2020). In another study from the same group, they observed improved intestinal development and higher daily weight gain in calves fed transition milk than in those fed milk replacer, alongside better health scores (Van Soest et al., 2022).
Some researchers have shown that longer periods of supplementation with colostrum or transition milk can be beneficial to prevent disease and mortality, and to reduce antimicrobial usage. Research conducted at Washington State University demonstrated that calves supplemented with 70 g of colostrum powder in the milk replacer for 14 days had a lower risk of scours and received less antibiotics than calves fed milk replacer only (Berge et al., 2009).
Beyond prevention, research has also indicated that colostrum may work as a supportive therapy for sick calves. Research conducted by Dr. Melissa Cantor, Assistant Professor of Precision Dairy Science at Penn State, showed that calves fed 125 g of colostrum replacer for 3 days after the onset of early clinical signs were significantly less likely to develop severe respiratory disease, suggesting that early intervention with colostrum may reduce disease impacts (Cantor et al., 2021).
Practical applications and important considerations
Whether extended colostrum feeding is practical depends on the availability of high-quality colostrum or transition milk, as well as on farm management and economic factors. Pooling colostrum or transition milk from different cows may increase risks of disease transmission, so producers should always consider herd health status and use pasteurization or alternative commercial replacers when appropriate.
Current research supports supplemental feedings for 3-14 days after birth, but there is no single protocol that fits every system. Producers can create protocols that work for their operation, evaluate, and modify them as needed. For instance, producers may choose to target calves that are at greater risk of diseases, such as low-birth-weight calves and calves born after difficult deliveries. Producers may also consider extended colostrum feedings during periods of heightened disease risks, such as during winter or periods of disease outbreaks.
Maintaining colostrum quality is essential. Collect and store colostrum or transition milk using strict hygiene practices to minimize bacterial contamination. Colostrum can be refrigerated for up to 3 days, and frozen for up to 6 months, preferably in small containers that allow fast cooling and thawing.
Regardless of the protocol that fits your operation, providing calves with an adequate first feeding of high-quality colostrum as soon as they are born remains an essential step in calf rearing. Research on extended colostrum feedings is promising and suggests beneficial effects on growth, disease prevention, and reduced antibiotic usage. However, more research is needed before standard recommendations can be made. Producers should first ensure that they are achieving excellent transfer of passive immunity at the herd level, before considering whether extended colostrum feeding fits the management goals and resources of their operation.
References
Berge, A.C.B., T.E. Besser, D.A. Moore, and W.M. Sischo. 2009. Evaluation of the effects of oral colostrum supplementation during the first fourteen days on the health and performance of preweaned calves. J. Dairy Sci. 92:286–295. doi.org/10.3168/jds.2008-1433.
Cantor, M.C., D.L. Renaud, and J.H.C. Costa. 2021. Nutraceutical intervention with colostrum replacer: Can we reduce disease hazard, ameliorate disease severity, and improve performance in preweaned dairy calves? J. Dairy Sci. 104:7168–7176. doi.org/10.3168/jds.2020-19654.
Renaud, D.L., and M.A. Steele. 2024. What can’t colostrum do? Exploring the effects of supplementing colostrum after the first day of life: A narrative review. JDS Communications 6:469–473.
Van Soest, B., F. Cullens, M.J. VandeHaar, and M.W. Nielsen. 2020. Short communication: Effects of transition milk and milk replacer supplemented with colostrum replacer on growth and health of dairy calves. J. Dairy Sci. 103:12104–12108. doi.org/10.3168/jds.2020-18361.
Van Soest, B., M. Weber Nielsen, A.J. Moeser, A. Abuelo, and M.J. VandeHaar. 2022. Transition milk stimulates intestinal development of neonatal Holstein calves. J. Dairy Sci. 105:7011–7022. doi.org/10.3168/jds.2021-21723.
This article was originally published and edited in Lancaster Farming on July 30th, 2026.
