Issue |
Reprod. Nutr. Dev.
Volume 43, Number 1, January-February 2003
|
|
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Page(s) | 17 - 28 | |
DOI | https://doi.org/10.1051/rnd:2003003 |
DOI: 10.1051/rnd:2003003
Influence of maternal environment on the number of transferable embryos obtained in response to superovulatory FSH treatments in ewes
Antonio González-Bulnesa, Rosa María García-Garcíaa, Vanesa Castellanosb, Julián Santiago-Morenoa, Carmen Ariznavarretab, Verónica Domíngueza, Antonio López-Sebastiána, Jesús A.F. Tresguerresb and María Jesús Coceroaa Dpto. de Reproducción Animal, INIA, avda. Puerta de Hierro s/n, 28040-Madrid, Spain
b Dpto. de Fisiología, Facultad de Medicina, Universidad Complutense de Madrid, 28040-Madrid, Spain
(Received 30 January 2002; accepted 10 June 2002)
Abstract
In a first experiment, embryo viability was estimated after recovery
in the uterus or the oviduct of 70 Manchega ewes following a treatment
of superovulation with decreasing doses of OVAGEN
TM. Fewer viable
embryos (5.6
0.9 vs. 8.3
0.8,
P < 0.05) and more degenerative
embryos (31.3% vs. 6.8%,
P < 0.005) were obtained from the uterus
than from the oviduct respectively. In a second experiment performed
on 14 ewes, embryo viability was analyzed in relation to the follicular
population estimated by ultrasonography (follicles
2 mm) at the first
FSH administration. Progesterone (P4) and oestradiol 17
(E2) concentrations
were also determined from the beginning of the superovulation treatment
to the recovery of the embryos. The number of viable embryos (4.3
1.4)
was positively correlated (
r = 0.824) with of 2-4 mm diameter follicles
(
P < 0.05), and with E2 concentrations at -12 h
(
r = 0.891,
P < 0.01) , 0 h (
r = 0.943,
P < 0.0001)
and +24 h (
r = 0.948,
P < 0.05) from estrus detection.
Prolonged high levels of E2 up to 72 h with low levels of P4
on days 3 and 4 after estrus had a negative (
P < 0.05) effect
on embryo viability. These results indicate that ovarian response
to superovulatory protocols is related to the individual variations
in the number of follicles of 2-4 mm at the start of FSH treatment,
and that embryo viability is conditioned by the steroid patterns
during the time spent in the genital tract of the super-ovulated ewes.
Key words: embryo viability / ewe / follicular status / super-ovulation / steroid
Correspondence and reprints: Antonio González-Bulnes
e-mail: bulnes@inia.es
© INRA, EDP Sciences 2003