The Jockey Club today released Report of Mares Bred (RMB) statistics for the 2019 breeding season. Based on RMBs received through October 16, 2019, The Jockey Club reports that 1,134 stallions covered 29,218 mares in North America during 2019.
The Jockey Club estimates an additional 2,500 to 3,500 mares will be reported as bred during the 2019 breeding season.
The number of stallions declined 6.6% from the 1,214 reported at this time in 2018, and the number of mares bred decreased 3.5% from the 30,274 reported last year. Consistent with prior years’ reporting of stallions by book size, the number of stallions covering 125 or more mares increased from 62 in 2018 to 65 in 2019.
Further book size analysis shows a 6.7% increase in the number of mares bred to stallions with a book size of 125 or more in 2019 when compared to 2018 as reported at this time last year; a 9.1% decrease in mares bred to stallions with a book size between 100 and 124; a 9.1% decrease in mares bred to stallions with a book size between 75 and 99; a 16.7% decrease in mares bred to stallions with a book size between 50 and 74; a 12.4% decrease in mares bred to stallions with a book size between 25 and 49; and a 1.0% increase in mares bred to stallions with a book size fewer than 25.
The percentage of broodmares covered by stallions serving 125 or more mares increased from 31.9% in 2018 to 35.3% in 2019. From 2015-2017, this percentage had remained fairly constant at approximately 29%, up from 20.5% in 2014.
The proportion of stallions with book sizes of 125 or more mares grew from 5.1% in 2018 to 5.7% in 2019. It had previously grown from 3.1% in 2014 to 4.5% from 2015-2017.
| 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | |
| % stallions with book size >125 | 3.1% | 4.5% | 4.5% | 4.5% | 5.1% | 5.7% |
| % mares covered by stallions with book size >125 | 20.5% | 29.1% | 28.7% | 29.4% | 31.9% | 35.3% |
Note: Statistics summarized as of October 16 of the breeding seasons indicated in the columns above; as reports of mares bred continue to be received, final statistics are subject to change.
RMB statistics for all reported stallions in 2019 are available through the Fact Book section of The Jockey Club’s website at jockeyclub.com.
The stallions Justify and Mendelssohn led all stallions with 252 mares bred by each in 2019. Rounding out the top five by number of RMBs were Into Mischief, 241; Uncle Mo, 241; and Goldencents, 239.
Kentucky traditionally leads North America in Thoroughbred breeding activity. During 2019, Kentucky’s 220 reported stallions covered 17,123 mares, or 58.6% of all of the mares reported bred in North America. The number of mares bred to Kentucky stallions decreased 1.1% percent compared with the 17,322 reported at this time last year.
Of the top 10 states and provinces by number of mares reported bred in 2019, Pennsylvania and Oklahoma stallions covered more mares in 2019 than in 2018, 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 2019:
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.
