American breeding continues to decline as Kentucky increasingly concentrates the business

The Jockey Club projects just 16,500 Thoroughbred foals in the North for 2027, as the number of stallions and mares bred continues to decline. Sierra Leone led the stallion ranks by book size, covering 293 mares

LEXINGTON, Kentucky (Special for Turf Diario).— The Thoroughbred industry in the United States faces a transformation that extends well beyond the decline in the number of foals. There are fewer stallions, fewer broodmares in production, and an increasing concentration of activity in Kentucky, while numerous regional programs continue to lose ground at a concerning pace.

The latest report released by The Jockey Club provides figures that illustrate the scale of the issue. For 2027, a registered foal crop of 16,500 is projected, down from the 17,000 estimated for 2026. The difference represents a drop of nearly 3% and extends a downward trend that has persisted for several years.

The estimate stems from the Report of Mares Bred for the 2026 breeding season, which stallion owners must submit by August 1 of each year.

Based on data received through October 1, a total of 670 stallions covered 23,932 mares in the United States. Compared to the same point in 2025, the number of stallions decreased by 9.2%, while the number of mares bred fell by 3%.

The comparison is particularly revealing: a year ago, 738 stallions and 24,662 covered mares had been declared.

The Jockey Club estimates that between 2,000 and 3,000 mares have yet to be incorporated into the final season records, though that adjustment is not expected to alter the general direction of the statistics.

Fewer stallions; more covers

One of the most significant aspects of the report is that the number of stallions is dropping at a considerably faster rate than the number of mares.

As a result, the average book size per stallion increased from 33.4 in 2025 to 35.7 in 2026, signaling that activity is progressively concentrating within a smaller group of farms and stallions.

This phenomenon is especially visible in Kentucky, which not only maintains its historic leadership but continues to expand its market share within North America.

During 2026, the 187 stallions residing in Kentucky covered 16,677 mares, accounting for 69.68% of the North American total.

The figure represents a 1.9% growth compared to the previous year, despite the state having two fewer stallions. In terms of market share, Kentucky moved from concentrating 66.4% of mares bred in 2025 to virtually 70% in 2026. Additionally, the average book size per stallion rose from 86.6 to 89.2.

This means that Kentucky accounts for just 27.9% of North American stallions, yet concentrates nearly seven out of every ten mares bred.

The strengthening of its industry is linked, among other factors, to revenues generated by Historical Horse Racing (HHR) wagering, which helps fund purse structures and incentive programs for breeding and racing.

The scenario changes significantly when analyzing what occurs across the rest of the continent.

Excluding Kentucky, the number of mares bred decreased by 12.5%, falling from 8,292 to 7,255, while the stallion population dropped 12%, from 549 to 483.

In other words, virtually all the contraction in North American breeding activity took place outside of Kentucky. Some traditional jurisdictions registered particularly severe declines.

California recorded a 13.9% decrease in mares bred and a 14.9% decline in stallions. Florida, another historic center of American breeding, lost 14.6% of its covers and 22% of its stallions.

In Ontario, Canada, the drop in mares bred reached 23.2%, while Louisiana suffered a 43.3% reduction.

Declines were also registered in Puerto Rico, down 32.7%, and West Virginia, with a 20.2% decrease.

These numbers reflect the difficulties faced by many regional operations to sustain their activity against the growing dominance of Kentucky. However, the outlook is not uniformly negative.

New York managed to increase its number of mares covered by 14.2%, rising from 1,119 to 1,278, while its stallion roster grew from 29 to 34.

Improvements were also seen in Oklahoma, which posted a 25.8% growth in covers and a 25% increase in stallions.

Virginia more than tripled its number of mares bred compared to 2025, while Manitoba, Wyoming, Arizona, and Iowa also showed progress.

For The Jockey Club, these results demonstrate that incentive programs and the strengthening of local opportunities can generate growth even within a contracting overall market.

Sierra Leone, the most in-demand

The report also sheds light on which stallions were the most active during the 2026 season.

Leadership belonged to Sierra Leone (Gun Runner), who received 293 mares, followed closely by Tiz the Law(Constitution) with 288, and Citizen Bull (Into Mischief) with 261.

Behind them were Gun Runner (Candy Ride) with 250 covers, and Gunite (Gun Runner) with 236. Also standing out were Not This Time (Giant's Causeway) with 230 mares, and Justify (Scat Daddy) with 205, two stallions of enormous global influence.

In total, 17 stallions covered 200 or more mares during the season, illustrating the immense size that the books of the most sought-after stallions can reach.

The Jockey Club also reported that 180 mares participated in the Mare Incentive Program, an initiative announced in December 2024 to encourage the return to breeding of mares that appeared to have left production.

The program includes the waiver of certain registration fees for foals born in 2027 out of qualifying mares.

The organization considers that reclaiming broodmares and strengthening regional programs is essential to slowing the decline in production.

In line with this goal, it created the position of Director of State and Provincial Breeders Programs, which will be filled by Najja Thompson beginning October 28.

His role will involve working alongside breeders' associations, racetracks, and industry stakeholders to identify successful incentives and promote their implementation in other jurisdictions.

The Jockey Club also announced that it will publish the final statistics for the 2025 breeding season during October, including the 2026 foal crop reports.

The organization's conclusion is clear: the challenge facing American breeding is no longer merely producing more foals, but also preventing the industry from becoming concentrated in a single major breeding hub.

Kentucky continues to strengthen, and top-tier stallions are receiving increasingly larger books. On the other hand, numerous regional operations struggle to maintain their viability.

It is a reality that forces the industry to consider not only the size of future foal crops, but also the economic and geographical structure that Thoroughbred breeding will hold in the years to come.