Ultrasonography of the ovaries and uterus and grey scale analysis of the endometrium during embryonic diapause in European roe deer

Abstract

of the ovaries and uterus and grey scale analysis of the endometrium during embryonic diapause in European roe deer. Acta Theriologica 45: 559-572.Knowledge about the mechanisms of embryonic diapause in European roe deer Capreolus capreolus (Linnaeus, 1758), although first described 140 years ago, is not extensive. In contrast to post mortem publications, this is an in-vivo study which monitored individual ovarian and uterine dynamics during diapause by transrectal ultrasonography. Ten roe deer were examined at 4 to 6-week intervals starting from the end of the breeding season (August) until after implantation (January). Sonographic appearance of corpora lutea and their average number observed per animal did not differ between pregnant (3.6) and non-pregnant (3.2) does prior to implantation. However, in pregnant animals (n = 5) endometrial changes associated with embryonic diapause were identified. The endometrium in pregnant does were low in echogenicity compared to the non-pregnant. Changes in echogenicity of the endometrium were first detected three months before implantation. Observed endometrial changes were quantified by computer-assisted grey scale analysis. Mean medians of grey scale histograms were lower in pregnant compared to non-pregnant animals beginning as from October. In late December and January, embryonic structures were detected in animals in which a low echogenic endometrium had been observed earlier. Ultrasonography and grey scale analysis characterised efficiently the dynamic processes in the uterus and ovary during embryonic diapause in pregnant and non-pregnant roe deer.

Physiologically Persistent Corpora lutea in Eurasian Lynx (Lynx lynx) – Longitudinal Ultrasound and Endocrine Examinations Intra-Vitam

“…Pallas' cat [11] ) or extending the duration of pregnancy (delayed implantations, e.g. : roe deer, some mustelidae [33] , [34] ). Lynx seem to have developed a quite remarkable alternative strategy, where they limit the period of fertility by converting a poly-estrous cycle into a mono-estrous cycle.…”

Reproductive history and absence of predators are important determinants of reproductive fitness: the cheetah controversy revisited

“…The ultrasound probe was fixed to a rigid extension (Schnorrenberg, Woltersdorf, Germany) specifically designed for transrectal examination of medium‐sized mammals (Hildebrandt et al 2000b). Compared with conventional transabdominal ultrasound, transrectal ultrasound provides unmatched high‐resolution images, since the acoustic coupling of the ultrasound probe on a wet, thin intestinal mucosa facilitates the accurate interpretation of fine tissue structures (Hermes et al 2000). It can also distinguish between hydro‐salpinx (oval shape, with fluid‐filled lumen surrounded by thin, rough, and spiky wall) and paraovarian cysts, that is, remnants of Wolffian glands (round shape, with fluid‐filled lumen surrounded by thick, smooth, homogeneous wall).…”

The concept of superfetation: a critical review on a ‘myth’ in mammalian reproduction

“…Dormant blastocysts can be present in the uterus for varying periods of time depending on the species (days to weeks in some mice or many years in kangaroos). Delayed nidation often leads to variable pregnancy length because of different time intervals between fertilization and implantation as for example in the American mink (Dukelow, 1966) and roe deer ( Capreolus capreolus ) (Hermes et al , 2000). Delayed nidation was also described as a cause of “split parturition” in the breeding pig (Vandeplassche, 1969).…”