The Jockey Club today released Report of Mares Bred (RMB) statistics for the 2015 breeding season. Based on RMBs received through October 13, 2015, The Jockey Club reports that 1,449 stallions covered 34,627 mares in North America during 2015.

Based upon historical reporting trends, The Jockey Club estimates an additional 2,000 to 3,000 mares will be reported as bred during the 2015 breeding season.

The number of stallions declined 6.3% from the 1,547 reported at this time in 2014, and the number of mares bred increased 0.3% from the 34,540 reported at this time last year.

The number of stallions covering 100 or more mares increased from 97 in 2014 to 105 in 2015. These stallions accounted for a greater percentage of the total mares reported bred this year — 41.8% of all mares bred in 2015 versus 36.4% of all mares bred in 2014 as reported at this time last year. RMB statistics for all reported stallions in 2015 are available through the Fact Book section of The Jockey Club’s website at jockeyclub.com.

Further book size analysis shows an 15.2% increase in the number of mares bred to stallions with a book size of 100 or more in 2015 when compared to 2014 as reported at this time last year; a 13.9% decrease in mares bred to stallions with a book size between 75 and 99; a 0.9% decrease in mares bred to stallions with a book size between 50 and 74; a 22.2% decrease in mares bred to stallions with a book size between 25 and 49; and no change in mares bred to stallions with a book size fewer than 25.

The stallion Uncle Mo led all stallions with 221 mares bred in 2015. Rounding out the top five were Scat Daddy, 217; Into Mischief, 210; Shanghai Bobby, 202; and Temple City, 199.

Kentucky traditionally leads North America in Thoroughbred breeding activity. During 2015, Kentucky’s 208 reported stallions covered 17,448 mares, or 50.4% of all of the mares reported bred in North America. The number of mares bred to Kentucky stallions increased 3.7% percent compared with the 16,826 reported at this time last year.

Of the top 10 states and provinces by number of mares reported bred in 2015, Kentucky, California, Ontario and Maryland stallions covered more mares in 2015 than in 2014, as reported at this time last year. The following table shows the top 10 states and provinces, ranked by number of mares reported bred in 2015:

Note: Each incident in which a mare was bred to more than one stallion and appeared on multiple RMBs is counted separately. As such, mares bred totals listed in the table above may differ slightly from counts of distinct mares bred. 

In addition, Report of Mares Bred information on stallions that bred mares in North America is available through report 36P or a subscription service at equineline.com/ReportOfMaresBred.

The Jockey Club, founded in 1894 and dedicated to the improvement of Thoroughbred racing and breeding, is the breed registry for North American Thoroughbreds. In fulfillment of its mission, The Jockey Club provides support and leadership on a wide range of important industry initiatives and it serves the information and technology needs of owners, breeders, media, fans and farms, among others. Additional information is available at jockeyclub.com.