1. Post-graduation Program in Veterinary Medicine, Health Center and Rural Technology, Federal University of Campina Grande, Patos 58708-110, Brazil.
2. Academic Unit of Veterinary Medicine, Health Center and Rural Technology, Federal University of Campina Grande, Patos 58708-110, Brazil.
3. Department of Veterinary Morphology, Center of Agrarian Sciences, Federal University of Piaui, Minister Petrônio Portela Campus, Teresina 64049-550, Brazil.
4. Department of Animal Physiology, Complutense University of Madrid, 28040 Madrid, Spain.
5. Department of Morphology, Federal University of Rio Grande do Norte, Natal 59078-970, Brazil.