1. Department of Gynecology, Federal University of Piauí, Teresina, Piauí, Brazil,
2. Veterinary Hospital, Federal University of Piauí, Teresina, Piauí, Brazil,
3. Department of Statistics, São Paulo University, São Paulo, Brazil, and
4. Genetics and Molecular Biology Laboratory, Federal University of Piauí, Teresina, Brazil