Relationship between corpus luteum size as determined by ultrasonography and milk progesterone concentration during the estrous cycle in dairy cows

젖소에서 발정주기중 초음파 진단장치로 측정된 황체의 크기와 progesterone 농도와의 관계

  • Son, Chang-ho (College of Veterinary Medicine, Chonnam National University) ;
  • Kang, Byong-kyu (College of Veterinary Medicine, Chonnam National University) ;
  • Choi, Han-sun (College of Veterinary Medicine, Chonnam National University)
  • Received : 1995.06.19
  • Published : 1995.10.30

Abstract

Ultrasonography was used to measure the corpus luteum area for determining the relationships between corpus luteum size and milk progesterone concentration during the estrous cycle in 16 dairy cows. Cows were classified retrospectively into cows that had corpus luteum with(n=P) and without(n=7) cavity. Ultrasound examination and collection of milk samples for progesterone assay were performed with 2 day intervals from Days 0 to 12, and then daily from Day 14 to the day of the next ovulation. The means for corpus luteum area and for milk progesterone concentration during the estrous cycle were not significantly different between cows that had corpus luteum with and without cavity. The correlation coefficients between corpus luteum area and milk progesterone concentration during luteal development (Days 2 to 8) were 0.71(p<0.0001) and 0.74(p<0.0001) for corpus luteum with and without cavity, respectively, during luteal regression(Days -6 to 0 relative to the next ovulation) 0.73(p<0.0001) and 0.76(p<0.0001), respectively. The correlation coefficients combined fur both stages of estrous cycle and both luteal statuses were 0.70(p<0.0001). These results indicate that corpus luteum area is significantly correlated to milk progesterone concentration, and ultrasonographic assessment of the corpus luteum is a reliable method fur estimating peripheral progesterone concentrations during the estrous cycle in cows.

Acknowledgement

Supported by : 농촌진흥청