Joy B. Gilbert

Number of Stallions and Mares Bred in 2017 Drops

Number of stallions bred slides 5.7%, while the number of mares bred declined 5.6%.

The Jockey Club released Report of Mares Bred statistics Oct. 25 for the 2017 breeding season. Based on data received through Oct. 17, 2017, The Jockey Club reports that 1,342 stallions covered 31,863 mares in North America during 2017.

Based upon historical reporting trends, The Jockey Club estimates an additional 2,000 to 3,000 mares will be reported as bred during the 2017 breeding season.

The number of stallions declined 5.7% from the 1,423 reported at this time in 2016, and the number of mares bred decreased 5.6% from the 33,746 reported last year. The number of stallions covering 125 or more mares decreased from 64 in 2016 to 60 in 2017.

Further book size analysis shows the following:

  • a 3.3% decrease in the number of mares bred to stallions with a book size of 125 or more in 2017 when compared to 2016 as reported at this time last year. However, the percentage of mares bred to stallions with books of 125 or more rose to 29.4% from 28.7% in 2016;
  • a 13% decrease in mares bred to stallions with a book size between 100 and 124;
  • a 27.4% decrease in mares bred to stallions with a book size between 75 and 99;
  • a 11.5% decrease in mares bred to stallions with a book size between 50 and 74;
  • a 14.9% increase in mares bred to stallions with a book size between 25 and 49; and,
  • a 4.7% decrease in mares bred to stallions with a book size fewer than 25.

When comparing statistics based on reports received through the same day (Oct.17) from previous breeding seasons, the percentage of stallions with books of 125 or more has held steady at 4.5% for the third consecutive year.

RMB statistics for all reported stallions in 2017 are available through the Fact Book section of The Jockey Club's website at jockeyclub.com.

Spendthrift Farm's Into Mischief  led all stallions with 235 mares bred in 2017. Rounding out the top five by number of RMBs were Darby Dan Farm's Dialed In  with 231; Ashford Stud's American Pharoah  with 214, and Uncle Mo  with 204; and, WinStar Farm's Bodemeister  with 192.

Kentucky traditionally leads North America in Thoroughbred breeding activity. During 2017, Kentucky's 229 reported stallions covered 17,275 mares, or 54.2% of all of the mares reported bred in North America. The number of mares bred to Kentucky stallions decreased 2.7% percent compared with the 17,750 reported at this time last year.

Of the top 10 states and provinces by number of mares reported bred in 2017, Ontario, Pennsylvania, and Indiana stallions covered more mares in 2017 than in 2016, 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 2017.

The proportion of stallions with book sizes of 125 or more mares grew from 2.6% in 2013 to 4.5% in 2015. It has remained constant at that rate over the past three breeding seasons. 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.