by Dean A. Hoffman

Forty-nine trotting and pacing stallion served a book of at least 100 mares in 2006, and two stallions, both in Canada, bred more than 200 mares.

Leading the way was the Alberta stallion As Promised, with 246 mares. That book actually amounted to a substantial drop from 2005, when As Promised bred 315 mares.

In the past five breeding seasons, As Promised has bred 1,360 mares, or an average of 272 mares per year. He is an 18-year-old son of Abercrombie, from Promised Princess, by Niatross. He took a 1:50.2 mark as a 4-year-old, and he’s sired 28 pacers with 1:55 or faster records, including Ron’s Girl p, 5, 1:49.3s ($576,458).

Another Canadian stallion, the Little Brown Jug winner Astreos, also bred more than 200 mares last year, as he checked in with a book of 207 mares. The son of Artsplace died unexpectedly last year while doing southern hemisphere stud service in New Zealand.

The busiest stallion in the United States last year was Rocknroll Hanover, the reigning Horse of the Year. He served a book of 189 mares in his first season at Perretti Farms in New Jersey.

Artsplace, sire of Astreos, bred 182 mares last year before falling victim to laminitis a few weeks after Astreos died. Artsplace had been a champion sire many times, and his offspring were always in great demand. The sons and daughters of Artsplace have earned more than $116.4 million.

The most active trotting stallion in North America was Muscles Yankee, whose book was 179 last year. He was followed closely by the father-son team of S J’s Photo and SJ’s Caviar, with 174 and 173 mares, respectively. S J’s Photo was exported to Italy last fall.

Listed below are the stallions in North America that bred 100 mares or more last year.