HIGH PREGNANCY RATES IN TWO-YEAR-OLD WILD HORSES

Abstract

Abstract In November 2018, we screened 315 feral Horse mares via veterinary rectal palpation and trans-rectal ultrasound, approximately 1 mo after their capture and removal from the Warm Springs herd management area in Oregon. We documented a pregnancy rate (58.3%) in 2-y-old mares that was nearly 3 times higher than previously published results. For 1-y-old mares (10.8% pregnant), and for mares pooled over all ages (64.4% pregnant), pregnancy rates were within the range of pregnancy rates reported from other feral Horse populations. High pregnancy rates in 2-y-old mares could contribute to higher than expected herd growth rates in feral Horses.