Cytological evaluation of neutrophil infiltration in different uterine regions of sows destined for slaughter: implications for reproductive diagnosis

Abstract

The aim of this study was to determine the neutrophilic polymorphonuclear infiltrate and the
association between the portion of the uterus and the ovarian phase. Eighty-seven genital tracts were
used from slaughtered sows. Samples were taken for cytology with an endocervical brush, on the body,
distal horn, middle horn and proximal horn. The samples were stained with Romanovsky stain. Up to
200 cells were counted, considering endometrial cells and neutrophils. The statistical analysis was
performed with a Poisson model and determined a higher count of neutrophilic polymorphonuclear in
the body with respect to the horns (P≤0.01), but it was not associated with the ovarian phase (P=0.29).
To determine the relationship between neutrophil count and ovarian phase, a mixed Poisson
regression model was used. The neutrophilic polymorphonuclear count is higher in the follicular
phase than in the luteal phase (P=0.11) and was only significant in the distal horn (P<0.01). It can be
concluded that there is a variation in the number of neutrophils between portions of the uterus,
independent of the estrous cycle. Cytology of the uterine body is a possible tool in live females for the
diagnosis of endometritis and its implication in reproductive performance.