When Should Foals Be Weaned? by KER

Despite the widespread custom of weaning foals within six months of birth, best practices for weaning have yet to be established, according to some behavioural experts.^*

Under natural conditions, weaning occurs over the course of several months beginning when the foal is 9 to 11 months old. Together, the mare and foal initiate weaning, and their bond remains close for some time afterward, sometimes until the mare’s next foal is born. While the origin of early weaning remains unclear, most private and commercial breeders separate mare-foal pairs 4 to 7 months after birth.

Advocates of early weaning suggest this benefits mares and foals because:

• Maternal milk production decreases dramatically by the third month of lactation, and the nutritional needs of the foal cannot be met by maternal milk supply alone. Thus, early weaning facilitates management of the foal’s nutritional intake without maternal interference;
• Early marketing of foals can only be possible with early weaning;
• A foal’s attention will be transferred from mare to human; and
• Mare reproductive efficiency can be optimized by limiting the potential negative effect of prolonged nursing.

On the flip side, early weaning can be problematic. Examples of some detriments associated with early weaning include:

• Altered behavior such as increased long-distance whinny calls and increased elimination, altered feeding and sleeping patterns, though usually temporary;
• Increased locomotion and therefore increased risk of injuries, also transient;
• Foal aggression, suspension of play activities, redirected suckling;
• A potential cause of stereotypical behaviors; and
• Negatively affecting the development of a healthy intestinal microbiome.

“Weaning is widely recognized as a major source of stress that can lead to long-lasting effects on welfare and immunity,” said Kathleen Crandell, Ph.D., a nutritionist for Kentucky Equine Research.

“Regardless of how weaning is achieved, it is a stressful event. Supplementing mares with omega-3 fatty acids during gestation and nursing, then both mare and foal after weaning will help to support healthy immune systems.”

^*Henry, S., H. Sigurjónsdóttir, A. Klapper, et al. 2020. Domestic foal weaning: Need for re-thinking breeding practices? Animals (Basel) 10(2). pii: E361.