Credit: Thinkstock A positive relationship was identified between foal average daily gain (ADG) and rainfall, suggesting ADG’s will be higher during periods of greater rainfall.

Researchers from the University of Kentucky have shown that pasture growing conditions can influence average daily gain (ADG) in foals.

A group of 320 Thoroughbred foals were regularly weighed between birth and weaning. Estimates of ADG were calculated for all foals at 3 or 4 months of age in May, June, July and August. During these months, foals (and mares) were kept on predominantly cool-season grass pastures. Information on daily rainfall was also collected.

A positive relationship was identified between ADG and rainfall, suggesting ADG’s will be higher during periods of greater rainfall. Results showed that ADG was within or above suggested ranges during May, but below ranges during June, July and August. Higher rainfall, paired with the cooler temperatures of May, likely increased pasture growth, nutrient availability, and subsequent foal ADG. However, in later summer months, ADG was below expected rates, suggesting supplementation may be necessary when pasture growth is depressed due to weather conditions.

Summarized by Jennifer Earing, PhD, University of Minnesota Equine.