Reproductive careers of Thoroughbred broodmares before and after surgical correction of ≥360 degree large colon volvulus.

This study looks into the reproductive performance of Thoroughbred broodmares before and after they undergo surgical correction for a severe type of colon twist (≥360° large colon volvulus or LCV). The researchers found that mares could still have productive careers after surgery, however, their age at the time of the operation greatly influenced their ability to bear foals post-surgery.

Study Methodology

• The investigators conducted a retrospective case series involving Thoroughbred broodmares that underwent surgical correction for ≥360° LCV and survived post-treatment in the Rood and Riddle Equine Hospital over a span of 15 years (from January 2000 to December 2015).
• This study only included those mares which were officially registered with The Jockey Club.
• Data on the mares’ reproductive careers were collected from both the hospital’s medical database and The Jockey Club produce records.
• Researchers primarily evaluated the data with parametric and nonparametric tests, considering P-value ≤0.05 for statistical significance.

Characteristics of the Studied Sample

• Among the studied population, 19 mares never foaled before their respective surgeries. These mares on average had a 4.4-year career duration and produced around 3.1 foals.
• A majority of the mares (565) had already delivered at least one foal before they underwent surgery. These mares, in contrast, had a career span of around 10.4 years and bore approximately 7.4 foals.

Findings of The Study

• Mares that had already delivered foals prior to surgery on average produced more foals and had longer breeding careers before undergoing surgery compared to their post-operative performance.
• No significant difference was observed regarding career length or number of foals delivered between mares undergoing single vs multiple LCV surgeries.
• Mares that underwent surgery at an age between 3 and 11 years had significantly more foals post-surgery than mares that underwent surgery at the age of 12 or older.

Conclusion

• The study concluded that Thoroughbred broodmares remained fertile and could bear foals post-surgery for ≥360° LCV, largely influenced by mares’ age during the time of surgery.