Ultrasonographic characterization of the uteri and ovaries of fertile sows after weaning and at the post-weaning oestrus.

摘要

Objective: This study was aimed to characterize the uteri and ovaries of fertile sows after weaning and at the post-weaning oestrus by means of transcutaneous ultrasonography. Material and methods: Sows (parity 3-12) were scanned one day after weaning and 100 h after a eCG application (800 IU given intramuscularly 24 h after weaning) at the presumed oestrus. Parameters evaluated were uterine echotexture (graded 1-4; 1=homogeneous, 4=most heterogeneous) and uterine size (expressed as the mean of the sectional areas (SA) of two or three cross-sections of the uterine horns; SA=(a/2) x (b/2) x pi ; a=maximum, b=minimum dimension of the cross-sections). The ovarian structures were recorded, and follicles (if present) measured. Females were inseminated at the post-weaning oestrus, and pregnancy was checked by ultrasonography on day 28 thereafter. Sixty-two (of 80) sows scanned met the prerequisites for inclusion in the statistical analysis, i. e. oestrus (standing response and peri-ovulatory ovarian structures) 100 h after eCG, pregnancy, complete data record. Results: The follicles were significantly smaller one day after weaning than at oestrus (0.41+or-0.07 vs. 0.70+or-0.10; p<=0.001). One day after weaning the uterine echotexture was more homogeneous and the uteri smaller than at oestrus (mean echotexture grade: 1.2+or-0.3 vs. 3.0+or-0.5; mean uterine size: 1.5+or-0.5 cm2 vs. 2.6+or-0.7 cm2; both p<=0.001). Changes in the uterine echotexture were positively related to changes in the uterine size (r=0.5; p<=0.001). Conclusions: Between the day after weaning and the subsequent oestrus, the porcine uterus undergoes ultrasonographically recognizable changes in its echotexture and size, which are presumably due to an increase of endometrial oedema, under the control of oestrogens and are accompanied by specific ovarian structures. Practical relevance: If the uterine echotexture and size is to be assessed it is necessary to consider that both parameters exhibit physiological variations dependent on the reproductive stage or stage of the oestrous cycle. Where the latter is unknown, adequate information can be obtained through the examination of the ovaries..