1. Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, Kentucky, USA 40546
2. Theriogenology Department, University of Mansoura, Egypt 35516
3. Department of Population Health and Reproduction, University of California, Davis, CA 95616
4. Department of Biomedical and Diagnostic Sciences, University of Tennessee, USA
5. Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
6. Department of Molecular Biosciences; University of California, Davis, CA 95616