The Jockey Club released Report of Mares Bred statistics for the 2020 breeding season Oct. 23. Based on RMBs received through Oct. 18, The Jockey Club reports that 1,067 stallions covered 27,970 mares in North America during 2020.
The Jockey Club estimates an additional 2,500-3,500 mares will be reported as bred during the 2020 breeding season.
At this time last year, The Jockey Club reported 29,218 mares were covered by 1,134 stallions. The numbers reflect a 4.3% decrease in the number of mares bred and 5.9% reduction of the number of stallions in service.
RMB statistics for all reported stallions in 2020 are available through the Fact Book section of The Jockey Club's website at jockeyclub.com.
Of note is the number of stallions covering 125 or more mares. That figure increased from 62 to 65 from 2018 to 2019 but saw a decrease to 54 for 2020.
Kentucky traditionally leads North America in Thoroughbred breeding activity. During 2020, Kentucky's 200 reported stallions covered 16,391 mares, or 58.6% of all of the mares reported bred in North America. The number of mares bred to Kentucky stallions decreased 4.3% percent compared with the 17,123 reported at this time last year.
Of the top 10 states and provinces by number of mares reported bred in 2020, stallions in Louisiana, Maryland, Pennsylvania, and New Mexico covered more mares in 2020 than in 2019, 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 2020:
| State/Province | 2019 Stallions | 2020 Stallions | Pct. Change | 2019 Mares Bred | 2020 Mares Bred | Pct. Change |
| Kentucky | 220 | 200 | -9.10% | 17,123 | 16,391 | -4.30% |
| California | 124 | 103 | -16.90% | 2,018 | 1,766 | -12.50% |
| Florida | 81 | 73 | -9.90% | 1,863 | 1,721 | -7.60% |
| Louisiana | 79 | 74 | -6.30% | 984 | 1,017 | 3.40% |
| New York | 43 | 37 | -14.00% | 1,058 | 1,002 | -5.30% |
| Maryland | 31 | 29 | -6.50% | 780 | 806 | 3.30% |
| Pennsylvania | 28 | 37 | 32.10% | 686 | 734 | 7.00% |
| Ontario | 29 | 24 | -17.20% | 538 | 519 | -3.50% |
| Oklahoma | 38 | 40 | 5.30% | 479 | 476 | -0.60% |
| New Mexico | 51 | 48 | -5.90% | 437 | 453 | 3.70% |
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.
Leading the ranks of mares bred are two of the top stallions of 2019. Uncle Mo , currently second on the list of leading sires by Northern Hemisphere progeny earnings, covered 257 mares in 2020. Uncle Mo stands at Ashford Stud. Second with 248 mares covered is last year's leading sire and this year's current leading sire and sire of 2-year-olds Into Mischief . Into Mischief stands at Spendthrift Farm. The other stallions that covered more than 200 mares were Mendelssohn , Vino Rosso , Constitution , Mitole , Justify , Audible , Omaha Beach , Munnings , Palace Malice, and Goldencents . Those stallions all stand in Kentucky.
In the regional markets, Khozan led all other Florida-based stallions with 181 mares; Solomini covered 123 mares in New York; Stay Thirsty covered 108 mares in California; Hoppertunity had 107 mares in Pennsylvania, and Golden Lad led all other Maryland sires with 103.
In addition, Report of Mares Bred information on stallions that bred mares in North America is available through report 36P or via a subscription service at Equineline.com.
