A sárgatest, az üreges sárgatest, a sárgatest- és luteinciszta kialakulásának etiológiája és pathogenezise valamint hatása a tejelő szarvasmarhák fertilitására

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 8 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.