Statistics from The Jockey Club for the 2011 North American breeding season show the number of stallions that serviced mares fell 11.5% and the number of mares bred declined 10% when compared to the same period a year ago.

Based on the Report of Mares Bred received through Oct. 12, 2011, The Jockey Club reported that 1,935 stallions covered 36,504 mares in North America. Based on reports through the same period one year ago, 2,186 stallions had serviced 40,576 mares.

The annual RMB includes the number of mares bred to each stallion and represent approximately 90% of the mares that eventually will be reported as bred in 2011. The Jockey Club estimates an additional 3,500 to 4,000 reports of mares bred to be received before the end of the year.

Among the top 10 breeding states and provinces by number of mares reported bred in 2011, only the Canadian province of Ontario reported stallions covering more mares than in 2010, as reported at this time last year. The number of stallions in Ontario fell from 78 to 71, but the number of mares bred through Oct. 12 rose just under 1%, from 1,383 to 1,396.

In Kentucky, which traditionally has the highest number of stallions and mares bred, 228 reported stallions covered 15,714 mares, or 43% of all of the mares reported bred in North America (up from 42.6% last year). The number of stallions servicing mares in Kentucky declined 14.3% to 228 and the number of mares bred to Kentucky stallions was down 9.2% from the 17,303 reported at this time last year.

The greatest changes in number of stallions servicing mares and mares bred came in Oklahoma and Pennsylvania. Oklahoma’s stallion population fell 24% from 129 to 98, according to The Jockey Club Report, and the number of mares bred declined 18.6%. Pennsylvania reported a 20.6% drop in its stallion population, from 97 to 77, and the 1,188 mares bred represented a decline of 23% from 1,542.

The following table shows the top 10 states and provinces, ranked by number of mares reported bred in 2011 through Oct. 12, 2011:

Note: Each incidence 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.

The number of stallions covering 100 or more mares increased from 82 in 2010 to 84 in 2011 and accounted for 30.6% of the total mares reported bred this year. In 2010, 26.8% of all mares bred were covered by stallions with 100 or more mares.
 
Further book size analysis shows a 2.5% increase in the number of mares bred to stallions with a book size of 100 or more in 2011 when compared to 2010; a 32.2% drop in mares bred to stallions with a book size between 75 and 99; a 17.8% decline in mares bred to stallions with a book size between 50 and 74; an 8.0% decrease in mares bred to stallions with a book size between 25 and 49; and an 11.4% decline in mares bred to stallions with a book size fewer than 25.
 
Congrats   led all stallions with 205 mares bred, followed by Giant's Causeway  , 198; Bellamy Road  , 192; Scat Daddy  , 191; and Henrythenavigator, 189.
 
RMB statistics for all reported stallions in 2011 are available through the Publications & Resources section of The Jockey Club’s website.