Weaning Strategies in Foals: Clinical Approaches, Behavioral Impact, and Practical Farm-Level Management

Weaning is one of the most critical transitional phases in a foal’s early life, carrying lasting implications for growth, health, behavior, and future performance. Over the years, a variety of weaning techniques have been practiced, with no universally ideal method. The selection of a weaning system depends on farm resources, managerial expertise, herd size, mare condition, and the number of foals being weaned simultaneously¹. 

Traditionally, many farms rely on total and abrupt weaning, where the mare and foal are suddenly separated by a distance sufficient to prevent visual and auditory contact. However, growing scientific interest has focused on how the timing and method of weaning influence stress responses, immune function, and behavioral development. This article reviews commonly practiced weaning schedules, their clinical relevance, and evidence-based recommendations for minimizing stress while maintaining optimal growth². 

Neonatal Weaning: Indications and Clinical Concerns 

Neonatal weaning, defined as separation within the first few days of life, is uncommon but clinically justified in specific circumstances. One of the most frequent reasons is long-distance transport of mares to reproductive facilities, where travel stress may compromise foal welfare³. Additionally, udder trauma in the early postpartum period may provoke aggressive nursing avoidance by the mare, making neonatal weaning unavoidable. 

Foal rejection by the mare, most often seen in maiden mares, is another recognized indication. In unfortunate cases of mare death during or shortly after parturition, neonatal weaning becomes a necessity rather than a choice². 

From a physiological perspective, early separation appears to provoke less overt stress compared to later weaning. However, the nutritional and behavioral challenges are substantial. The mare’s milk is uniquely suited to meet neonatal nutritional demands, and training a neonate to accept milk replacer from a bucket is time-intensive. Additionally, concerns persist regarding whether neonatally weaned foals can adequately develop normal social and species-specific behaviors without maternal cues. Criticism has also been directed at the potential negative impact of neonatal weaning on growth rates if nutrition and monitoring are inadequate². 

Clinical takeaway: Neonatal weaning should be reserved for unavoidable medical or management emergencies and requires intensive nutritional, behavioral, and health monitoring². 

Two-Month Weaning: Early Separation and Behavioral Implications 

It has been proposed that the mare–foal bond begins to weaken naturally around two to three months of age, making this an alternative window for weaning². Before implementing two-month weaning, careful assessment of foal growth rate, body condition, and overall health is essential. Smaller or slower-growing foals are typically left with their dams longer, while robust foals may tolerate earlier separation. 

Advocates of two-month weaning cite benefits such as reduced mammary stress in mares and lower injury risk due to the foal’s smaller size. However, these claims lack strong empirical validation. Successful early weaning at this stage depends heavily on a well-formulated creep feeding program to compensate for lost milk nutrition ². 

Behavioral development is a major concern. Research suggests that dominance hierarchies in adult horses may be influenced by early social interactions, with foals of dominant mares often becoming dominant adults themselves. Since temperament and aggression are, to some extent, learned behaviors, early weaning may reduce the transfer of undesirable behavioral traits from poorly tempered mares. Conversely, owners of well-mannered mares may benefit from prolonging the dam–foal relationship to reinforce positive behavioral traits². 

Clinical takeaway: Two-month weaning may be selectively useful but should be avoided in compromised foals and always paired with structured nutrition and behavioral oversight. 

Four-to-Six-Month Weaning: The Industry Standard 

The most widely practiced method in modern equine operations is abrupt weaning at four to six months of age. Many owners believe that continued nursing beyond this stage places excessive metabolic strain on the mare, particularly those in suboptimal body condition⁴. 

Physiologically, while mare’s milk adequately supplies minerals during early lactation, it no longer fulfills the foal’s energy requirements by four months of age. Therefore, foals must already be nutritionally independent if this weaning window is chosen². 

Importantly, management interventions such as vaccination and castration should be completed well in advance or at least one month before weaning, to avoid compounding stressors. Behavioral adaptation during this phase can be assessed using a behavior score index based on cortisol levels, ACTH response, feeding behavior, vocalization, and activity patterns. Scores range from 1 to 10, with higher scores indicating better adaptation². 

Interestingly, foals weaned individually demonstrated better behavioral adaptation than those weaned in pairs, as reflected by higher behavior scores⁵. 

Clinical takeaway: Four-to-six-month weaning is effective when foals are nutritionally prepared and health procedures are completed well before separation. 

Gradual Weaning Techniques: Reducing Stress Through Management 

Conventional weaning often coincides with multiple stressors, new environments, castration, deworming, first exposure to creep feed, and halter training. Recognizing this, researchers have evaluated gradual and partial separation techniques aimed at reducing stress⁵. 

Behavioral Responses to Gradual Weaning 

McCall and colleagues examined foal behavior across five weaning systems, using vocalization, activity, and feeding behavior as stress indicators. Foals receiving creep feed consumed diets containing 16% crude protein and were handled regularly before weaning². 

Their findings demonstrated that complete isolation without creep feed resulted in the highest stress behaviors, while partial separation combined with creep feeding significantly reduced vocalization and activity levels. Notably, creep-fed, partially separated foals behaved similarly to unweaned controls². 

Physiological Responses to Gradual Weaning 

Stress responses were further evaluated through basal cortisol levels and adrenal responsiveness to ACTH. Foals subjected to abrupt, total separation showed significantly elevated cortisol responses, regardless of creep feeding. In contrast, partially separated foals exhibited no significant cortisol elevation, closely resembling unweaned foals ⁶. 

Clinical takeaway: Gradual weaning combined with creep feeding is consistently associated with lower behavioral and physiological stress responses. 

Practical Weaning Recommendations for Farm Success 

Given the diversity of farm conditions, no single weaning strategy is universally applicable. However, strong scientific evidence supports the use of creep feeding alongside gradual, partial separation to minimize stress and promote healthier growth². 

Weaning management should be structured into three phases: 

• Pre-weaning: birth to initiation of separation 

• Weaning: the 2–3 day separation period 

• Post-weaning: the following 1–2 weeks 

Health Programs 

A proactive health program is essential. Foals should be first dewormed at 8 weeks and begin vaccinations at 3 months, following current veterinary guidelines. Completing these procedures before weaning helps protect immune function during this stressful transition². 

Creep Feeding 

Foals should be accustomed to creep feed well before weaning to prevent digestive upset. For foals older than four months, mare’s milk alone is insufficient to meet energy demands. A balanced 16–18% crude protein concentrate is recommended. Intake should approximate one pound per month of age per day prior to weaning². 

Facilities and Safety 

Weaning facilities must prioritize safety, with secure fencing, non-slip flooring, absence of sharp objects, minimal dust, and adequate shelter from adverse weather². 

Handling and Training 

Early handling, including halter training while the foal remains bonded to the dam, improves trainability. Younger foals learn more readily than older horses, and many operations incorporate imprinting techniques as part of their handling strategy². 

Conclusion 

For many equine enterprises, weanlings represent a primary economic asset. Excessive stress during weaning can compromise growth potential, increase illness risk, and place young horses at a disadvantage in competitive settings. While weaning is an unavoidable transition, it need not be traumatic. 

With thoughtful planning, appropriate nutrition, preventive healthcare, and evidence-based weaning strategies, farm managers can support the development of healthier, better-adjusted weanlings. Attention to detail and preparation remain the defining factors in successful weaning outcomes. 

References 

1. Henry S, Sigurjónsdóttir H, Klapper A, Joubert J, Montier G, Hausberger M. Domestic foal weaning: need for re-thinking breeding practices?. Animals. 2020 Feb 23;10(2):361. https://www.mdpi.com/2076-2615/10/2/361 

2. Khalid U, Rehman HU, Abbas S, Ullah MS, Idrees H. Optimizing Foal Care: Best Practices and Management Strategies. Optimizing Foal Care: Best Practices and Management Strategies.  https://biologicaltimes.com/wp-content/uploads/journal/published_paper/volume-2/issue-11/BT_2023_800792.pdf 

3. Canisso IF, Podico G, Ellerbrock RE. Diagnosis and treatment of mastitis in mares. Equine Veterinary Education. 2021 Jun;33(6):320-6. https://www.abvp.com/wp-content/uploads/2021/11/EQUINE-NOVDiagnosis-and-Treatment-of-Mastitis-in-Mares-EVE.pdf 

4. Tang C, Cai M, Wang L, Guo Y, Li N, Feng Y, Xiao L. Genetic diversity within dominant Enterocytozoon bieneusi genotypes in pre-weaned calves. Parasites & Vectors. 2018 Mar 12;11(1):170. https://link.springer.com/content/pdf/10.1186/s13071-018-2768-x.pdf 

5. Van Kerschaver C, Turpin D, Michiels J, Pluske J. Reducing weaning stress in piglets by pre-weaning socialization and gradual separation from the sow: a review. Animals. 2023 May 15;13(10):1644. https://www.mdpi.com/2076-2615/13/10/1644  
6. Arnaud EA, Gardiner GE, Lawlor PG. Selected nutrition and management strategies in suckling pigs to improve post-weaning outcomes. Animals. 2023 Jun 15;13(12):1998. https://www.mdpi.com/2076-2615/13/12/1998