VA RIA BILITY OF OVARIAN STRUCTURES AND PLASMA PROGESTERONE PROFILES IN DAIRY COWS WITH OVARIAN CYSTS D. J. Carroll,1 R. A. Pierson,3 E. R. Hauser,* R. R. Grummerlp and D. K. Combs,l IDepartment of Dairy Science *Department of Meat and Animal Science University of Wisconsin-Madison Madison, WI 53706 Received for publication: zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQ November 20, 2989 Accepted: May 21, 1990 A BSTRA CT Weekly reproductive health examinations were performed on 46 multiparous Holstein cows from 14 to 100 d post partum. Sixteen cows developed 19 nonsimultaneous ovarian cysts, with a mean day of first detection at 34.3 + 4.5 d post partum and a mean duration of 31.0 + 4.3 d after first detection. Coccygeal blood was collected three times weekly, and plasma progesterone concentrations were determined by radioimmunoassay. Cysts were diagnosed by palpation per rectum or by ultrasonography and classified as follicular or luteal cysts; the cows were not treated. Cows with a mean plasma progesterone concentration of < 1 ng/ ml from the first day of detection (Day 1) of a cyst until Day 10 were classified as having a follicular cyst, and those with a mean plasma progesterone concentration of 2 1 ng/ ml from Day 1 to Day 10 were classified as having a luteal cyst. According to this classification, 58% of the cysts were follicular and 42% were luteal. There was an overall 47% agreement between classification by palpation and by ultrasonography on Day 1 with progesterone concentration during Days 1 to 10 after detection of the cyst. Detailed graphs of progesterone concentrations and area of largest follicles or cysts and corpora lutea demonstrate the variability of ovarian structures and progesterone profiles in cystic cows. Detection of a cyst at any one time accompanied by simultaneous measurement of progesterone can lead to different diagnoses of cyst type depending on the method of classification, the presence and age of luteinized tissue in the cyst and undetected corpora lutea. Key words: ovarian cysts, plasma progesterone, ultrasonography, palpation Acknowlegements: The authors thank Missi Hatfield, Kevin Jorgensen and Sara Maurer for their help in collecting and analyzing samples. 3 Current address: Reproductive Biology Research Unit, University of Saskatchewan, Saskatoon, Saskatchewan, Canada. 4 Reprint requests. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA AUGUST 1990 VOL. 34 NO. 2 349