OVARIAN HAEMODYNAMICS AND FERTILITY IN CATTLE

Abstract

Ovarian vasculature is an important supportive component that ensures the fertility of an animal. Angiogenesis
involves the formation of capillaries from pre-existing microvessels and therefore contributes to vascular remodelling
and maturation. This process allows adequate nutritional and hormonal supply for ovarian follicle growth and corpus
luteum (CL) formation. Colour-Doppler ultrasound has been used for studying vascular perfusion of ovarian structures
and to analyse the blood flow parameters through Doppler spectrum. The ovarian follicle and CL are the major sites
of active angiogenesis suggesting that a strong association between normal functionality of these structures and the
network of blood vessels. Rapid pulse frequency of the peri-follicular blood flow is a prerequisite factor for induction of
ovulation process. Sequential observation during an oestrous cycle revealed progressive increase in luteal blood flow
with the increasing endocrine activity. There was an intense increase in luteal blood flow between days 15 – 17 of the
oestrous cycle coinciding with the luteolysis. A deficient blood supply to the ovaries could disturb the follicular
development, maturation and ovulation leading to various pathological conditions like anoestrus and cystic ovarian
degeneration. More clinical research trials are required to develop suitable therapeutic protocols to modulate ovarian
vascularity in order to enhance the fertility of cattle.