Zenyatta, the 2011 Horse of the Year, is no longer in foal after five weeks of pregnancy and will be bred to Bernardini again next week, according to Mike Cline, the manager of Lane's End Farm, where the seven-year-old mare is boarded.\r\n&quot;She came up empty on a 35-day [pregnancy] check today,&quot; Cline said. &quot;It's not uncommon. It's unfortunate, but she's healthy, she's doing great, and we expect her to get back in foal.&quot;\r\nZenyatta was bred on Feb. 23 to Bernardini, a son of A.P. Indy who was the champion 3-year-old colt of 2006. A previous ultrasound check one week ago had indicated that she was in foal.\r\nDr. Etta Bradecamp, a fertility specialist at Rood and Riddle Equine Clinic in Lexington, Ky., said that studies of mares have indicated that young mares are the least likely to experience early embryonic loss, and that studies of entire mare populations have indicated that approximately 7 to 10 percent of mares will experience it over a breeding season.\r\n&quot;It's not common, but I wouldn't say it's uncommon either,&quot; Bradecamp said. She said that causes of early embryonic loss in young mares like Zenyatta are not yet understood, whereas in older mares it is typically attributed to the effects of aging on reproductive cells.\r\nWord of the development was first posted on zenyatta.com, a website that maintains a diary purported to be written by the mare, and it prompted an outpouring of sympathetic notes from Zenyatta's legion of fans within an hour of its posting. The diary is written by Dottie Ingordo-Shirreffs, the wife of Zenyatta's former trainer, John Shirreffs, and the racing manager for the mare's owners, Ann and Jerry Moss.\r\n&quot;In life, we all have things that don't always go as hoped or planned,&quot; Ingordo-Shirreffs wrote. &quot;I am not any different than anyone else.&quot;\r\nA poster using the screen name Jeanie responded: &quot;Oh, sweetie, I am so sorry. I just got a knot in the pit of my stomach when I read this. You are so brave. I know it will happen for you.&quot;\r\nJessica wrote: &quot;Awh, poor Z. When will you get to try again? Best wishes.&quot;\r\nBy Street Cry, Zenyatta became the only mare to have won the Breeders' Cup Classic, in 2009. She finished second in the race in 2010, posting the first loss of her 20 starts, but was voted the Horse of the Year over the Classic winner, Blame.\r\nBernardini stands for $75,000 at Sheikh Mohammed al Maktoum's Darley Stud at Jonabell Farm in Lexington.