Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias

16 t h International Congress on Animal Reproduction
Poster Abstracts 109
Miniature mares are a potential model for comparative studies in
folliculogenesis within and among species.
P244
The effect of interval from mating to ovulation on
pregnancy rates and incidence of intra-uterine fluid in the
mare
Newcombe, JR 1 *; Cuervo-Arango, J 2
1Equine Fertility Unit, Warren house farm, Brownhills, UK; 2 Royal Veterinary
College, Department of Veterinary Clinical Science, University of London, UK
Introduction Persistent mating-induced endometritis (PMIE) is
known to be one of the main factors affecting pregnancy rates in the
mare. There has been extensive research on causes and treatments of
PMIE, however the interval from mating to ovulation (IMO) has
never been considered as a possible factor affecting the outcome of
PMIE and pregnancy rates. It is thought that natural cover is best
performed close to ovulation (0-48 h prior to ovulation) in order to
achieve optimum pregnancy rates. However, to date it is not known
whether mating “problem mares” at that interval will be detrimental
for pregnancy rates (PR). The objectives of this study were: a) to
assess the effect of IMO on PR and on the incidence of intra-uterine
fluid (IUF) 72 h post-mating (PM); and b) to determine the effect of
free IUF 72 h PM on PR.
Material and methods A total of 439 cycles from 315 Thoroughbred
mares were analysed. Mares were examined by transrectal
ultrasonography every other day until the mare was free from IUF (up
to 96 h from mating). Pregnancy diagnosis was preformed by
ultrasound 12-13 days post-ovulation and rechecked by 30 days. For
each mare, age, date of mating, name of stallion used, number of
services, IMO and depth of IUF 72 h PM were recorded. For data
analysis, three groups of IMO were used (0-48, 48-96 and 96-144 h).
A statistical general model of analysis of variance was used to assess
the effect of stallion, IMO, age and presence of IUF 72 h PM on PR.
Chi-square test was used to analyse the association among IMO, PR
and IUF 72 h PM.
Results Stallion, age and IMO had no effect (P > 0.05) on overall (all
services) PR. Pregnancy rates in mares with IUF 72 h PM was
reduced by 17.7 % (P < 0.01). Mares mated at the interval 0-48 h preovulation
were more likely (P < 0.01) to have IUF 72 h PM than at
48-96 and 96-144 h (68, 42 and 41 % respectively). Pregnancy rates
on first service were (69.3, 73.3 and 68.4 % for intervals 0-48, 48-96
and 96-144 h respectively, P > 0.05). However, on second service (n =
88 mares) they were lower (P < 0.05) in mares mated 0-48 h (54.5 %)
than in those mated 48-96h before ovulation (79.1 %) .
Conclusion Incidence of IUF 72 h PM is highest in mares mated 0-48
h before ovulation. Mating 0-48 h before ovulation is detrimental for
PR in mares which failed to conceive in first service. It appears that in
“problem mares” with delayed uterine clearance, a longer IMO gives
the mare an “extra” time to clear the uterine inflammation before the
cervix closes under progesterone influence.
P245
Apoptotic markers can be used to forecast the
freezeability of stallion spermatozoa
Ortega Ferrusola, C 1 *, Gallardo Bolaños, JM 1 , Gonzalez Fernandez, L 2 ,
Rodriguez-Martinez, H 3 , Tapia, JA 2 , Pena, FJ 1
1Reproduction, University of Extremadura, Spain; 2 Physiology, University of
Extremadura, Spain; 3 Reproduction, SLU, Sweden
In an attempt to identify valuable markers for potential freezeability
of the equine spermatozoa, three ejaculates were collected from five
Andalusian stallions and frozen using a standard protocol. Before
freezing, three apoptotic cell markers were studied by flow cytometry
(early changes in sperm membranes, mitochondrial membrane
potential and caspase activity). Post-thaw, spermatozoa were again
evaluated for these parameters and for sperm kinematics using CASA.
Receiving operating system curves were used to evaluate the relative
value of the apoptotic markers herein studied, as forecast for potential
freezeability. From all parameters studied, the outcome of JC-1 (as
proportion of spermatozoa showing simultaneously orange and green
fluorescence) had the highest diagnostic power. For potentially bad
freezers (less than 25% of intact spermatozoa post-thaw), the
significant area under the ROC-curve was 0.985, with a 100%
sensitivity and 99.8% specificity for a cut off value of 55.7.
P246
Effect of altrenogest-treatment in late pregnant-mares on
parturition, neonatal adaptation and adrenocortical
function in new-born foals
Palm, F 2 *; Neuhauser, S 1 ; Ambuehl, F 1 ; Moestl, E 3 ; Aurich, C 1
1Centre for Artificial Insemination and Embryo Transfer; 2 Clinic for Obstetrics,
Gynaecology and Andrology; 3 Institute for Biochemistry, University of Vet.
Sciences, Vienna, Austria
In mares with compromised pregnancies, treatment with the synthetic
gestagen altrenogest (allyltrenbolon) is common to maintain gestation
until term. However, there are no controlled studies on the effects of
altrenogest administration during late pregnancy on parturition and
development of the foals in the immediate postpartum period. In our
study, pony mares with normal pregnancies were treated with
altrenogest (0.088 mg/kg bwt; n=6) from day 280 of gestation until
spontaneous parturition or were left untreated as controls (n=7).
Stages of labour and clinical parameters were analysed and blood
samples were collected from immediately after birth until 48 hours
post natum for analysis of cortisol concentration, haematolgical and
acid base parameters. In order to assess adrenocortical function, an
ACTH stimulation test with 0.125 mg ACTH (Synacthen, Novartis)
was performed on days 1 and 5 after birth and cortisol release
calculated as area under the curve for the time period 0 to 120 min
after cortisol injection. Altrenogest-treated mares tended to have a
shorter gestation length (320±4 days) than control mares (327±2 days)
and showed a prolonged second stage of labour (p