Sampling follicular fluid without altering follicular status in cattle: oestradiol concentrations early in a follicular wave

Abstract

oestradiol, 30\p=n-\42 ng ml \ m=-\ 1). The mean diameter of the dominant follicle increased linearly over the 4 days. Concentrations of oestradiol in the dominant follicle increased curvilinearly, resulting from a slower increase between days 1 (mean, 42 ng ml\m=-\1) and 2 (110 ng ml\m=-\1) than between days 2 and 3 (313 ng ml\m=-\1) and 3 and 4 (554 ng ml\m=-\1). Neither mean diameter nor mean oestradiol concentration of the largest subordinate follicle increased after day 2. Data were available from 19 follicular waves in which both the dominant and largest subordinate follicles were sampled on the same day. Oestradiol concentrations were not higher in the dominant follicle than in the largest subordinate follicle until the day after the two follicles began to deviate in growth rates (mean day of deviation, 2.5 \ m=+-\ 0.2 days after emergence). These observations indicate that the future dominant follicle cannot be identified reliably by either its diameter or oestradiol production before the deviation in growth rates between the two largest follicles.

Limitations of ultrasound guided follicular aspiration for analysis of ovarian follicular fluid in dairy cattle

“…These studies have described aspirations from single follicles of various sizes 6-12 mm (Ginther et al 1997), more than 8 mm (Leroy et el. 2004b) and more than 10 mm (Kendrick et al 1999) using needles of various diameters 17G (Kendrick et el.…”

“…2004b) and more than 10 mm (Kendrick et al 1999) using needles of various diameters 17G (Kendrick et el. 1999), 18G (Jorritsma et al 2003), 20G (de Castro e Paula et al 2008, 21G (Leroy et al 2004b) and 25G (Ginther et al 1997). Unsuccessful aspirations were the result of blood contamination of the follicular fluid (Ginther et al 1997;Jorritsma et al 2003), difficult manipulation of the ovaries (Ginther et al 1997) or by the rupture of follicles (de Castro e Paula et al 2008).…”

“…In vitro collection is performed from ovaries obtained from slaughtered animals (Wise 1987;Leroy et al 2004a;Orsi et al 2005) and in vivo aspiration is performed in live animals as well (Ginther et al 1997;Gérard et al 2002;Jorritsma et al 2003). The most frequently used method of in vivo aspiration is ultrasound guided transvaginal follicular aspiration (TVFA).…”

Promise of new imaging technologies for assessing ovarian function

“…2), horses (Bracher et al, 1993;Cook et al, 1993) and in women (Wikland et al, 1983) for the purposes of in vitro embryo production. The technique has also led to novel studies involving follicular fluid sampling (Ginther et al, 1997), local or intra-follicular injections Gastal et al, 1995), and gamete recovery and follicular transfer (Bergfelt et al, 1998;Hinrichs and DiGiorgio, 1991) to better understand the effects and capacity of individual follicles of a wave and their oocytes.…”

Follicular dynamic and ovulation in cattle – a review

“…It was speculated that acquisition of ovulatory capacity may involve an increased expression of LH receptors on granulosa cells of the dominant follicle and that this change may also be important for further growth of the dominant follicle (SARTORI et al, 2001). Observations of GINTHER et al (1997) indicate that the future dominant follicle cannot be identified reliably by either its diameter or estradiol production before the deviation in growth rates between the two largest follicles. Dominance appears to be maintained by negative feedback effects of products of the dominant follicle on circulating FSH.…”