Clinical Findings and Serum Steroid Hormone Concentrations in Sows with Post-Weaning Ovarian Disorders.

Abstract

The aim of this study was to diagnose ovarian disorders by evidence of external signs and through repeated rectal palpation in post-weaned sows. Blood samples were collected weekly from 59 sows with ovarian disorders from weeks 1 to 5 following weaning (the first examinations were done 7 to 10 days after weaning and were defined as post-weaned week 1), to determination progesterone (P) and estradiol-17β (E2) levels by radioimmunoassay. The ovarian disorders were devided into the following: ovarian subfunction (OS), small multiple follicular cysts (SMFC), large multiple follicular cysts (LMFC), large multiple luteal cysts (LMLC), and retention of corpora lutea (RCL). The ovaries, uteri, and vulvae were poor in sows with OS. Serum levels of P and E2 in sows with OS were low, and P levels decreased further in post-weaned week 3. In ovaries with SMFC and LMFC, numerous follicles less than 8-mm and 15- to 50-mm in diameter were observed, respectively. Animals with SMFC showed medium to high uterine contraction. There were differences in both follicular size and in the degree of uterine contraction between the sows with SMFC and LMFC. P levels remained low in both the sows with SMFC and LMFC, whereas E2 levels were persistently high. The walls of the LMFC were thin and weak, whereas those of the LMLC were thick, secure and tough. The sows with the latter type of cysts had high P levels, showing different findings from the sows with LMFC. Thus, LMLC and LMFC can be differentiated by the palpation characteristics of cyst walls and by serum P levels. In sows with RCL, the ovarian findings resembled those in the luteal phase of normally cycling sows, whereas LMLC ovaries were large. Therefore, RCL and LMLC could be differentiated by the size of the ovaries. These differential diagnoses will allow for appropriate treatments of sows with these ovarian disorders in the future.