Risk factors associated with the incidence of foal mortality in an extensively managed mare herd.

This research study investigates the risk factors associated with foal mortality within a large mare herd that is extensively managed. During a six-week span, a notable 22% of foal mortality was observed, highlighting the need to understand factors influencing this rate to devise effective management strategies.

Overview of the Research Study and Findings

• The study lasted for 6 weeks between the months of April and May in 1994 during which time 334 foals were born. Of these, 74 died before they reached 10 days old. This translates into an overall mortality rate of 22% for the period under study.
• Most of these deaths occurred within 48 hours of birth, which points to complications around pregnancy and parturition as potential risk factors.
• Starvation/exposure, septicemia, and dystocia were the leading causes of foal deaths, contributing to 27%, 26%, and 20% of the mortality respectively.
• The study found that the weekly incidences of foal death varied greatly, with the first week recording the highest mortality rate of 67% which then dipped to 14% by the fifth week.

Identified Risk Factors

• The study showed that several factors significantly contributed to foal death. These encompassed failure of passive transfer, which is the inability to receive essential antibodies from the mare’s milk, and poor mothering abilities in the mares.
• Dystocia, or difficulty in giving birth, low birth weight, lack of rainfall and low temperatures also appeared to have a notable impact. These factors were found to be statistically significant in the incidence of foal mortality.
• However, the researchers discovered that the influence of the sire (father), the age and body condition of the mare, and the sex of the foal were not significant risk factors for foal survival.

Implications and Future Research

• The high incidence of foal death in this study signals the necessity for further studies to ascertain if changes in management procedures can help bring down neonatal foal mortality in extensively managed herds.
• Because most deaths occurred early after birth, focus on improving pregnancy and parturition conditions, along with active measures to ensure the newborn foal receives adequate nutrition directly after birth, could be beneficial.
• Finally, understanding and mitigating the environmental stressors like low temperatures and lack of rain, that were found to have significant bearing in this study, could also be crucial in improving foal survival rates.