The Bovine Model: Physiological
Significance of the High Variation in
Antral Follicle Count (AFC) during
Ovarian Follicular Waves in
Young Adults
Cumulative age associated with menopause (1), onset of irregular
menstrual cycles (2), end of fertility (3),
and beginning of subfertility (4).
te Velde et al., 1998. Mol Cell
Endo. 145:67-73.
*
*
*
*
*
*
*
*
*
*
*
*
Ovarian
Reserve
FSH & LH
Ovarian
Reserve
FSH & LH
Healthy
Degenerated
Primordial
1000 X
Transitory
1000 X
Primary
1000 X
Secondary
400 X
Antral
400 X
***
Variation in Number of
Morphologically Healthy
Oocytes/Follicles in Calves and
Heifers:
– 10,000 to 350,000
– 1,920 to 51,520
Does high variation in ovarian reserve
impact fertility? Can new methods to
predict, monitor and improve fertility be
developed? Mechanisms? Therapies?
Low
Day 4
LH (ng/ml)
0.40
High
0.33
0.33
0.26
0.26
0.19
0.19
0.12
0.12
0.05
0.05
0
2:00 4:00 6:00 8:00 10:0012:00
Day 11
0.40
0
2:00 4:00 6:00 8:00 10:0012:00
Time
P < 0.03, n = 11 animals
Bovine model: Physiologically significant
linkage exists, independent of aging,
between the inherently high variation in
AFC during follicular waves with size of
gonads, ovarian reserve, gonadotropin
secretion and action, ovarian function,
oocyte quality and uterine function, which
may in turn impact fertility and
reproductive longevity.
Variation in Number of
Morphologically Healthy
Oocytes/Follicles in Calves and
Heifers:
– 10,000 to 350,000
– 1,920 to 51,520
Weight in pregnant heifers carrying a single
female fetus
Weight (kg)
650
600
550
500
Control (n=13)
450
Restricted (n=10)
400
-20
30
80
130
180
Day of pregnancy
230
280
At birth
Body Weight (kg)
• Not different at birth: gestation length, placenta weight,
number of cotyledons, any measure of calf size, or birth
weight (C 40 ± 1 kg vs R 39 ± 2 kg)
280
230
180
130
80
30
Control (n 13)
0
4
8
12
16
20
24
Age (weeks)
28
32
36
40
Mean number of follicles ≥3 mm
at 7, 18 and 35 wks of age
Mean Fol. No.
■ Restricted
30
25
20
15
10
■ Control
*
*
*
7
18
35
Age (weeks)
t al
Systolic (mm Hg)
Blood pressure
160
Control
Restricted
150
140
130
120
110
Diastolic (mm Hg)
100
puberty
80
70
60
50
40
15
20
25
30
35
40
45
50
55
Age (weeks)
60
65
70
75
80
85
Mossa et al
Conclusions
Bovine major
is novel
biomedical
model(ovarian
to elucidate
Identified
source
of variation
reserve)
Phenotyping
cattle
based
on
AFC/AMH
may
be
useful to
causes
and
mechanisms
whereby
the
high
that is associated with marked alterations in ovarian
improve
experimental
design,insuperovulation,
and
variation
in
ovarian
reserve
single-ovulating
differentiation, function and responsiveness to
perhaps
(?) and function,
health (?)fertility
in cattle.
species
mayfertility
altergonadotropins.
ovarian
and
health of individuals.
“Not everything that
counts can be counted,
and not everything that
can be counted
counts”
Sign hanging in Einstein’s office at Princeton