Mares nurse their babies, known as foals. This nursing relationship is the foundation of the foal’s early life, providing nutrition, comfort, and security. Mare’s milk is perfectly formulated to support the rapid growth and development of the young horse during its first months. The nursing process dictates the foal’s health, immune status, and eventual transition to an independent diet.
The Foal’s First Meal: Colostrum
The mare’s first milk, called colostrum, is a thick, yellowish fluid fundamentally different from the milk produced later. This initial secretion is packed with antibodies, primarily Immunoglobulin G (IgG), concentrated in the mammary gland during late pregnancy. Foals are born with an immunologically naive system, meaning they have no circulating antibodies to fight common infections.
Ingestion of colostrum is the only way for the foal to acquire passive immunity from the mare. Specialized cells in the foal’s small intestine absorb these large antibody molecules intact, but this window is brief. The ability to absorb immunoglobulins declines after about 12 hours and is largely gone by 24 hours after birth, a process known as “gut closure.”
Failure to receive or absorb sufficient colostrum results in Failure of Passive Transfer (FPT), leaving the foal susceptible to life-threatening infections. A healthy foal needs to ingest two to three liters of high-quality colostrum within the first six to twelve hours of life for adequate protection. Veterinarians often test the foal’s blood for IgG levels around 12 to 24 hours of age to ensure successful immunity transfer.
Nursing Behavior and Frequency
A healthy newborn foal exhibits a strong suckling reflex and typically stands and nurses within two hours of birth. Foals nurse frequently, seeking the mare’s udder up to seven to ten times per hour during the first week of life. These sessions are short, lasting only a minute or so, ensuring a steady intake of small, digestible amounts of milk.
The mare’s milk composition changes rapidly to meet the foal’s escalating nutritional demands as it grows quickly, gaining one to three pounds per day. Mare’s milk has a relatively low fat content and a high sugar (lactose) content, contrasting with the milk of other species. This unique composition provides the necessary energy for the foal’s rapid development and high activity level.
The frequency of nursing gradually decreases as the foal matures, dropping to about three times per hour in subsequent weeks. The mare plays an active role, often initiating or allowing nursing while exhibiting protective behaviors. By two months of age, the foal’s nutrient requirements for growth begin to exceed what the mare’s milk alone can provide, though nursing continues.
The Natural and Managed Weaning Process
In a natural environment, the mare and foal initiate weaning gradually, concluding when the foal is between nine and twelve months old. This slow separation minimizes stress and allows the foal to transition to a forage-based diet over many months. The mare’s next pregnancy and the birth of a new foal often serve as the final catalyst for the previous foal’s independence.
In domestic management, foals are commonly weaned much earlier, usually between four and seven months of age. Managed weaning is often done to protect the mare’s health, prepare her for re-breeding, or facilitate the foal’s training and nutritional management. By four months, the foal’s nutritional needs are substantial, and early weaning allows for precise control over its diet.
Managed weaning can be achieved through several methods, including abrupt separation or more gradual techniques. Abrupt weaning involves the complete and immediate physical separation of the mare and foal, which causes temporary behavioral and physiological stress. Gradual methods, such as fence-line weaning where the pair can still see and touch but not nurse, are considered less stressful for the foal.
Caring for the Orphan Foal
When a foal cannot nurse from its dam due to death, illness, or rejection, immediate intervention is necessary for survival. The most pressing concern for a newborn orphan is securing a source of colostrum within the first 12 hours of life. This involves administering frozen colostrum from a colostrum bank or donor mare, or using a commercial, purified immunoglobulin product.
For long-term nutrition, the ideal solution is finding a nurse mare, which provides milk and necessary social and behavioral guidance. If a nurse mare is unavailable, the foal must be hand-raised using a milk replacer formulated for foals. Mare’s milk replacers are preferred because they mimic the low-fat, high-sugar profile of natural mare’s milk, unlike cow’s milk, which causes digestive upset.
Hand-feeding requires frequent, small meals, initially every one to two hours, to simulate the natural nursing pattern. Foals can be taught to drink from a bucket, which is less labor-intensive than bottle-feeding and reduces the risk of aspiration pneumonia. Orphan foals can be gradually weaned off milk replacer and onto solid feed as early as three months of age.