Estrus Identification Through Colpocytology in Sows in Intensive Free-Range Breeding

Abstract

The objective of the present study was to identify the first estrus postpartum, through vaginal cytology, in sows subjected to intensive free-range pig breeding (Sistema Intensivo de Criação de Suínos ao Ar Livre - SISCAL), in the northern region of the state of Tocantins. The assessment began 48 hours after farrowing, and continued until heat behavior was identified. This study was conducted at School of the Veterinary Medicine and Animal Science of the Federal University of Tocantins, at Campus de Araguaína, in the period between August/2010 and July/2011. The coefficients analyzed were the percentage of epithelial cells in the phases of postpartum anoestrus, proestrus and estrus, using vaginal smear cytology, in six sows, in which four types of cells were identified: parabasal, intermediary, superficial with nucleolus or without nucleus. During the weaning period until the onset of estrus, and during estrus, a higher percentage of superficial cells, with or without nucleus was detected (32.68% and 38.50%) and (51.67% and 58.0%), respectively. The conclusion was that, through vaginal smear cytology, it was possible to identify the onset of estrus in weaning sows, submitted to the intensive free-range breeding system (SISCAL), in the state of Tocantins, thus facilitating the identification of the best moment for natural breeding or artificial insemination, as with other species, such as dogs or goats.