Abstract

The aim of the current study was to use ultrasound imaging to follow the follicular dynamics in dairy cows and to determine the relationship between the diameter of the dominant follicle (DF), the life span of the corpus luteum (CL), interovulatory interval (IOI), and the number of follicular waves. Twenty nine Holstein normal cyclic cows 60 days postpartum were used in this study. The ovaries of the experimental cows were scanned for the DF and CL every three days from ovulation to ovulation. Cows undergo the Ovsynch program to unify the beginning of the ovulation per cycle.
The results revealed that, cows that exhibit the two wave patterns have a longer time of IOI than a cow with a one wave pattern (P

Key words: bovine ovary; estrous cycle; Corpus luteum; follicular dynamics; dairy cattle; Ultrasound.