Morphological examination of ovaries in gilts with not detected standing oestrus up to 240 days of age and later

Abstract

The main purpose of this study was to investigate the ovarian structures (corpora lutea, corpora hemorragica, corpora albicans) in the slaughtered gilts, with not detected standing oestrus up to 240 days of age and later. Post-mortem morphological examinations were done on ovaries from 233 gilts. The status of pubertal maturation was determined according to presence of functional ovarian structures: large follicles (6-11mm), corpora lutea, corpora hemorrhagica and corpora albicantia. Ovaries with large follicles, corpora lutea or corpora hemorrhagica, were considered as having one ovarian cycle. Ovaries with combination: large follicles + corpora albicantia, corpora hemorrhagica + corpora albicantia or corpora lutea + corpora albicantia were considered as having two ovarian cycles. Ovaries with only small folicles (≤ 5mm) were considered as prepubertal (acyclic) ones. According to functional ovarian structures, 57% of gilts were prepubertal (acyclic) and 43% had established pubertal cyclic ovarian activity. From total number of pubertal gilts, 65% had established one, and 35% - two pubertal ovarian cycles. Probably the lack of standing oestrus detection in 43% ovarian cyclic gilts were the consequence of (a) silent oestrus or (b) inadequate oestrus detection procedure. Post-mortem examination of reproductive organs was a valuable diagnostic tool for gilts with delayed prepubertal anoestrus.