Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias

16 t h International Congress on Animal Reproduction
84 Poster Abstracts
P169
Early sonographic diagnosis of embryo/fetal compromise
in sheep cloned derived pregnancies using heart rate,
crown rump length and abdominal circumference
measurements
Panarace, M*; Suarez, G; Cané, L; Garnil, C; Medina, M
GOYAIKE S.A.A.C.I. y F., Biotechnology Area, Carmen de Areco CC37, CP
6725, Buenos Aires, Argentina
Introduction Sheep cloning has been associated with an increased
incidence of abnormal development of the conceptus and a high rate
of pregnancy and neonatal loss. The overall efficiency remains low
and the production of live offspring is still an unpredictable event.
Thus, early prediction of the outcome of pregnancies initiated from
cloned embryos has became an important issue, both for reutilization
of recipients and also to prevent potential harm to the recipient, the
lamb or both. Ultrasonography has proven to be an important, noninvasive
method of screening that can be used as predictor of
embryo/fetal loss.
Objective The aim of this study was to determine if and which of the
in vivo ultrasound and Doppler observations of fetal and placental
development could be of predictive value for diagnosis of high-risk
pregnancies.
Materials and methods Forty-five natural-mated derived singleton
pregnancies were used as the control group (A). In addition, 113
Merino breed recipients bearing clones were split into three groups
according to the outcome of their pregnancies: (B) clones that died
between 31 and 90 days (n = 78), (C) clones that died between 91
days and 48 hours after birth (n = 33) and (D) clones alive with more
than six months old (n = 2). Measurements were taken every two
weeks by ultrasonography (Toshiba Nemio 20, Tokyo, Japan) using
two different convex probes, a 5-10 MHz from days 31 to 60 of
gestation (transrectal) and a 3-6 MHz thereafter (transabdominal).
Three parameters were measured: heart rate (HR, bpm) was
determined by Doppler interrogation of umbilical arteries; crown
rump length (CRL, mm) was measured in a longitudinal section of the
embryo and abdominal circumference (ABC, mm 2 ) was registered in a
cross section of the fetus abdomen. Data were analyzed by Chi-square
test and differences were considered significant when P < 0.05.
Results While fetal losses were relatively rare in ewes carrying
naturally mated ewes, losses were considerable in the cloned fetuses
(4% versus 97%, respectively). At 31 days of pregnancy 32% of
embryos that died before 90 days (B) and 21% of those that died after
90 days (C) had a HR < 188 bpm; the incidence of this abnormality
was higher (P < 0.05) in (B) and (C) than in (A) (0%). Also at 31
days, CRL < 16.5 mm was found in 14% of embryos in (B) being
different (P < 0.05) to that observed in (A) and (C), (0%). At 87 days
of gestation, 38% of the fetuses in (C) had ABC values > 228 mm 2 ,
this incidence was higher (P < 0.05) than that in (A), (0%). Given
these findings, it is entirely plausible that the early losses recorded in
our current study resulted partly from developmental defects of the
embryo/fetus proper and partly from placental failures (most of the
fetuses with enlarged ABC were simultaneously found with hydrops).
Conclusion A HR < 188 bpm or a CRL < 16.5 mm detected with
ultrasonography at 31 days of pregnancy were important markers for
clones that died between 30 and 90 days of gestation. In addition,
ABC at 87 days was a predictor of fetuses that developed large
offspring syndrome.
P170
Hyperglycaemia in day 9 of the estrous cycle did not
increase ovulation rate in ewes but modified plasma IGF-I
concentrations
Pérez-Clariget, R 1 *; López-Mazz, C 1 ; Regueiro, M 1 ; Crooker, BA 2 ; Carriquiry, M 1
1Department of Animal Production and Pastures, School of Agronomy,
UDELAR, Uruguay; 2 Department of Animal Sciences, University of
Minnesota, USA
To evaluate the effect on ovulation rate of increased glycaemia during
24 h in the luteal phase of cycling ewes, thirty-four non-lactating adult
Corriedale ewes (44.6±4.5 kg of body weight and 3.2±0.5 body
condition, in a scale 1-5) that grazed native pastures were used. Estrus
was synchronized with 2 doses of cloprostenol 8 d apart and on day 9
of the synchronized estrous cycle, ewes were randomly assigned to
receive an oral administration of a neoglucogenic solution (125 ml;
70% glycerol, 20% propilenglycol, 10% distilled water; n=17;
Group-G) or saline (n=17; Group-S), administrated every 6 h for a
24 h-period. All ewes were inseminated with fresh semen at the
following (natural) estrus and number of corpus luteum (CL) was
observed by laparoscopy at day 8 of the natural estrous cycle. Means
were considered to differ when P