| dc.description.abstract | Due to the unilateral selection of dairy cows for milk production in the last decades, fertility
problems occurred more frequently. Some of them are associated with formation of fluid filled
ovarian phenomena (ovarian cysts). Frequency, morphology and nomenclature of these
phenomena is not consistent in the literature, data about formation and etiology are
incomplete. The aims of this study were to describe the frequency, etiology, pathogenesis
and structure of fluid filled ovarian phenomena (except follicles), and based on findings
suggesting a suitable nomenclature.
As a first step, the frequency of fluid filled ovarian phenomena were examined in a dairy
farm, in postpartum (30-60 days postpartum) cows and post-insemination (28-60 days) cows
and heifers. In the next step, metabolic and rectal ultrasound examination were carried out
summer and winter, in a dairy farm with more than 11000 kg/cow/year milk production.
Finally, the structure, morphological and endocrinological characteristics of the ovarian
phenomena were determined based on analyzing of aspirated fluids and histological slides.
In post partum cows the frequency of fluid filled ovarian phenomena was 30,1%. In post
inseminated, open heifers approximately the same frequency was found (29,5%) and also in
open cows (37,6%). No significant differences were identified between post partum and post
insemination animals. After insemination, significantly more ovarian phenomena were found
in cows, than in heifers (P=0,006), and open cows had more anovulatory forms (P=0,01),
and more ovulatory forms were diagnosed in open heifers (P=0,01). Milk production, body
condition and unsuccessful insemination after spontaneous or hormonal treated
inseminations had no effect on frequency of different ovarian phenomena. There were more
ovulatory forms in heifers (P=0,001), while in cows anovulatory forms were detected more
often (P=0,001) which failed to conceive.
Significantly higher plasma NEFA and BHB concentrations were found in summer than in
winter (P<0,0001). This high plasma NEFA concentration looked to be in association with the
lower BCS caused by depressed appetite. Statistical analysis support the hypothesis that
increased plasma NEFA and BHB and decreased plasma IGF-I concentrations may result in
reduced fertility and can be associated with the more frequent appearance of fluid filled
ovarian phenomena.
In morphological examinations, fluid filled ovarian phenomena were allocated in two main
groups: ovulatory and anovulatory structures. According to the diameter, the cavity diameter
and wall thickness I suggested a modified nomenclature of fluid filled ovarian phenomena:
CL with cavity, cystic CL, persistens/anovulatory follicle, follicle-fibrous cyst and follicleluteinized
cyst. Ovulatory forms differed in cell distribution, lutein tissue volume and the
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thickness of connective tissue around the fluid filled cavity (P<0,07). High NEFA
concentrations in aspirated fluid suggest the possible role in formation of these phenomena.
In the aspirated fluid of the anovulatory forms 17-beta-estradiol concentrations were high,
and in samples from follicle-luteinized cysts progesterone concentrations were also high. | en |
