Ultrasonic Characteristics of Physiological Structures on Bovine Ovaries

Abstract

The use of diagnostic ultrasonography in veterinary medicine in general (23), and especially for the assessment of the bovine genital tract and ovarian structures (7,6,13,22), is not yet widespread, but is increasing rapidly. The topography of the bovine genital tract which cannot be visualized as easily as, for example, the genital tract of the mare, is the main reason why this technique is not yet so widespread in cows. The ovaries and the tips of the bovine uterine horns are not always easy to reach with the ultrasound transducer via the rectum, vagina or via the abdominal wall. Ultrasonography may be necessary when rectal palpation of the genital tract as well as hormone analysis do not give the desired information about normal or pathological ovarian activity. Visualization of the ovaries via rectum or vagina can give us extra information about the follicle population, the presence of functional corpora lutea, follicular and luteinized cysts, haematomas in the ovaries, ovarian responses to hormonal treatment (1,25) and abnormalities in the ovarian region. Other applications of ultrasonography in cows besides the study of ovarian structures include early pregnancy diagnosis (1,4,7,12,16,24,26), check of the age, sex and/or viability of the fetus, and aspiration of oocytes, the so-called “ovum pick-up” (15). The ultrasound scanning of bovine ovaries and the diagnostic reliability of this technique was first reported by Pierson et al. (11,13) and Quirk et al. (18). Changes in growth patterns of the follicles in the ovaries with the aid of (daily) ultrasound scanning have also been studied (22).