Mare Reproductive Loss Syndrome Farm Survey Results
Maxwell H. Gluck Equine Research Center
University of Kentucky College of Agriculture
September 14, 2001

The goals of the 11-page Mare Reproductive Loss Syndrome (MRLS) farm survey were to: identify factors with high association with MRLS early and late term abortions; identify protective factors which were in higher association with low or no loss farms compared to high loss farms; and determine areas needing further investigation.

133 farms participated in the survey: 66 farms were classified as early fetal loss (EFL)-only farms; 30 farms were classified as EFL and late term abortion (LTA) farms; 4 farms were classified LTA-only farms; 32 farms were control farms with low or no EFL or LTA; and1 farm was EFL and not at risk of any LTA (had no mares in late pregnancy).

Farm managers were asked if they had excessive losses for EFL or LTA in comparison to previous years to make this classification.

The questionnaire was analyzed utilizing several statistical methods to crosscheck results. The farm-based questionnaire evaluated farm management issues on the 133 farms. A pasture-based questionnaire evaluated the pasture with the most mare abortion losses and a pasture with the least number of losses per farm. A representative pasture holding at-risk mares was evaluated on low or no loss farms. This resulted in a total of 212 pastures evaluated in the study. Because of the low number of farms with only LTA, results apply to EFL and EFL/LTA farms