Morphological Changes in the Oviduct of Culling Replacement Gilts

Abstract

The aim of this study was to investigate the morphological changes of the oviduct from 30 culling replacement gilts and 6 control sows. Blood samples and female genital organs were taken immediately after slaughter. Post-mortem examinations were made on the genital organs and oviductal samples, i.e. utero-tubal junction (UTJ), isthmus and
ampulla, were collected and fixed for histological analysis. Observations indicated that the reasons for culling the gilts were 'no estrus' (68%) and 'repeat breeding' (32%). The greatest pathological changes (67%) were found in repeat breeding gilts, whereas 52% of no estrous gilts were at prepubertal phase. The female hormonal levels detected from
the majority of gilts corresponded to ovarian appearances. Microscopic findings of the gilt oviductal epithelium revealed that characteristics of secretory and ciliated cells similar to the sows and pathological abnormalities were found in some gilts. The cytoplasmic protrusions and periodic acid-Schiff (PAS) staining revealed variable results. The distribution of intraepithelial leukocytes was significant higher in no estrous/prepubertal gilts than follicular sows (p < 0.05). A significant decrease in epithelial cell height was observed in the UTJ and ampulla of culling gilts compared with sows (p < 0.05). In conclusion, the epithelial cell height was the essential parameter for indicating the morphological changes of culled gilt oviducts, whereas the distribution of intraepithelial leukocytes needs to be further studied. The results suggested that reproductive failures, i.e. no estrus and repeat breeding, were found in culled replacement gilts of some swine farms in Thailand and were involved in the proper functions of the oviduct.