AT foaling, a mare’s daily nutrient requirements increase significantly. The lactating mare requires more protein, energy, calcium and phosphorous in a larger amount of feed in order to recover from foaling stress, to produce milk and to prepare for the next covering.

Underfeeding of mares during early lactation will lower milk production and cause weight loss as well as delays in rebreeding times and lower conception rates. A lactating mare will require between 2–3% of her body weight in total feed daily.