1 Northwest Equine Reproduction Laboratory, Department of Animal and Veterinary Science and Center for Reproductive Biology, University of Idaho, Moscow, ID 83844.
| 2 Northwest Equine Reproduction Laboratory, Department of Animal and Veterinary Science and Center for Reproductive Biology, University of Idaho, Moscow, ID 83844.
| 3 Department of Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164.
| 4 Prairie Animal Hospital, 920 W Prairie Ave, Coeur d'Alene, ID 83816.
| 5 Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.
| 6 Animal, Dairy and Veterinary Science Department, Utah State University, Logan, UT 84322.