Hill 'n' Dale Farms at Xalapa's elite sire Curlin will stop covering mares for the remainder of the breeding season because of a low fertility issue that was suspected within the last 10 days.
The 22-year-old son of Smart Strike successfully bred 25-30 mares earlier in the year, but then a marked reduction in mares checked in foal started to appear in the second wave of mares the stallion covered, according to John Sikura, president and founder of Hill 'n' Dale.
Sikura said the stallion was evaluated April 22 by Dr. Dickson Varner, the recently retired professor of theriogenology at Texas A&M University's Department of Large Animal Clinical Services, who recommended the stallion stop breeding.
"We had a large enough sample size of mares not checked in foal and then confirmed the issue with expert opinion," Sikura said. "He is going to have to regenerate semen and it's a lengthy cycle, so we made the hard decision to take him off service and notified the shareholders and the breeders, so they can regroup."
Curlin also recently suffered from an ulcer that was diagnosed by Dr. Nathan Slovis with Hagyard Equine Medical Institute in Lexington and had spiked a fever, but Sikura said he does not know if these other health issues are connected to the low fertility being seen.
"The ulcer was outside his stomach, which Dr. Slovis said is highly unusual. And his fever reached 102 degrees but immediately came down with Banamine," Sikura said. "Maybe from the stress and a combination of factors it affected his (semen) sample. Hopefully everything will regenerate in his next cycle and through the fall, and we can breed him next year. We will be careful on numbers and do what's best for the customers and the horse. Right now, I don't want to look too far ahead of today."
With a stallion of Curlin's stature, Sikura said it was most important to get answers quickly and communicate them to the breeders who have supported the sire.
"Sometimes Mother Nature intervenes at the most inopportune times and everyone in this business experiences that," he said. "We did not want to sit on this and hold off on the hard decision because that would have been unfair to those who have committed very valuable mares. So we made the brave decision and made it quickly. Barbara Banke, the classy lady she is, fully supported it because she loves her horses.
"We're in the same boat as everybody else," Sikura noted. "We bred Cavalieri and Life Talk, two important mares, to him last week."
Curlin had been booked to 97 mares this year, according to Sikura.
Off a racing campaign that produced consecutive Horse of the Year titles in 2007-08 and more than $10.5 million in earnings, Curlin more than lived up to the high expectations when he retired to stud in 2009. He has sired 118 black-type stakes winners (8% from foals of racing age), which include 68 graded stakes winners and 11 champions.
He has consistently been among North America's most prominent sires since 2015, ranking among the top five leading general sires six times and being the second-leading sire three times. He finished 2021 and 2022 as the leading sire by number of grade 1 stakes winners with five and six, respectively. Additionally, Curlin was represented by three winners during each of the Breeders' Cup World Championships in 2022 and 2023.
"Hopefully, there is another year or two where he can still stand at stud," Sikura said. "If not, he's been a blessing and made a wonderful contribution to the breed and been a wonderful stallion for Hill 'n' Dale and Stonestreet. We don't want to look too far ahead of today's decision, but it has certainly been a bad day."
