Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias

16 t h International Congress on Animal Reproduction
Poster Abstracts 111
caused by more than one bacterial clone (64%), whereas this was a
less pronounced in infections coused by E. coli (36%). Finally, we
observed no difference in the genetic diversity among S. equi ssp.
zooepidemicus or E. coli isolated from clitoris of mares from the
closed herd when compared to isolates from mares kept as on an
individual basis. In conclusion, it appears that no specific strain of S.
equi ssp. zooepidemicus or E. coli cause infectious endometritis in the
mare. Furthermore, positive cytology is a not a reliable tool to
evaluate the infectious status as presence of PMN’s was absent in
33% or 67% of infections caused by S. equi ssp. zooepidemicus or E.
coli, respectively.
P251
Luteal function and ovulation in mares treated with pgf2α
during early and mid-diestrus
Holland, BE; Pinto, CRF*
North Carolina State University, College of Veterinary Medicine, Raleigh,
North Carolina 27606,USA
PGF 2α is commonly administered as single injection to mares with a
mature corpus luteum (days 5 to 7 post-ovulation. In the present
study, it was hypothesized that complete luteolysis (plasma
progesterone < 1.0 ng/mL) will be achieved in mares receiving PGF 2α
for 3 consecutive days beginning as early as 2 days after ovulation
(early diestrus). The specific objectives of the present study were to
document ovarian dynamics (follicular growth, ovulation, CL
formation) using transrectal ultrasonography, and luteal function
determined by concentrations of plasma progesterone (P 4 ). The effect
of intramuscular administration of 2.5 mg PGF 2α on luteal function
(dinoprost tromethamine) given on day 10 after ovulation (Group 1)
and on days 2, 3, and 4 (Group 2) was examined in a switch back
design utilizing horse mares (n = 10). Transrectal ultrasonography
was performed three times per week or once daily on mares in estrus
with follicle diameters ≥ 30mm. Blood samples were taken daily and
plasma samples were stored at -20 ˚C until RIA analyses for P 4 .
Statistical analyses were done by ANOVA, with significance level set
at P < 0.05; data are presented as mean ± SEM. All mares in Group 1
(control) underwent complete luteolysis 2 to 3 days after PGF 2α
treatment with a mean of 2.4 ± 0.16 days; all mares in Group 1
ovulated 8.2 ± 0.75 days following PGF 2α treatment. In Group 2 (early
diestrus), 6 out of 10 mares underwent complete luteolysis 3.3 ± 0.2
days after beginning of treatment on day 2 post-ovulation; these mares
ovulated 9.4 ± 1.36 days after treatment. The remaining 4 mares in
Group 2 underwent partial luteolysis followed by resurgence in
circulating concentrations of plasma P 4 ; 3 out of these 4 mares
ovulated with relatively high circulating concentrations of plasma P 4
at day 9 (P 4 = 3.3 ng/ml), 15 (P 4 = 2.99 ng/ml) and 16 (P 4 = 3.29
ng/ml) following treatment, respectively; whereas the remaining mare
underwent natural luteolysis 16 days after treatment with its ovulation
occurring on day 19 following treatment. Complete luteolysis
followed by ovulation was observed in 60% (5/10) of mares treated
during early diestrus. We concluded that the equine corpus luteum
could be responsive to exogenous PGF 2α as early as 2 days post
ovulation. Increasing the dose or frequency of PGF 2α treatment
during early diestrus may provide novel protocols for use in
broodmare management.
P252
Pregnancy diagnosis in the mare by semi quantitative
relaxin quick assay kit
Ponthier, J 1 *; Van de Weerdt, M-L 2 ; Deleuze, S 1
1Equine Reproduction, Equine Veterinary Teaching Clinic, Faculty of
Veterinary Medicine, ULg, University of Liege, B41, 20, Boulevard de
Colonster, B-4000 Liege, Belgium; 2 Lab For Vet, 31 Rue Laoureux, B-4800
Verviers, Belgium
Few hormonal assays for pregnancy diagnosis are available in the
mare. Progesterone assay is not sensitive, not predictive of foetal
viability and is useless after day 120 of pregnancy. PMSG or eCG
diagnosis is short-windowed (from day 45 to 100) and can give falsepositive
results (in case of embryo mortality). Urinary estrogens assay
is only reliable in late pregnancy (after day 150) and requires bladder
catheterism. Estrone sulfate measurement predicts foetal viability but
is inadequate before day 100. Relaxin, a polypeptid produced by the
placenta in the mare, the bitch and the queen, is a candidate for the
pregnancy diagnosis and the foetal viability prognosis. Rapid
immunological tests have been developed to detect relaxin after day
28 of pregnancy in the bitch and 31 in the queen. In the bitch,
circulating relaxin measured by immunological procedure is at 1ng/ml
at 4 weeks and peaks at 4ng/ml at 6 weeks. In the queen, relaxin is at
5ng/ml at day 31 and reaches 9ng/ml at day 40. In pregnant mares,
relaxin detected by chromatography is basal until day 80 and then
reaches 80ng/ml for the mare and 10ng/ml for the pony mare. From
there on, concentration will increase in the pony and decrease in the
horse. In both cases, concentration falls dramatically at parturition.
The aim is to study the validity of a commercially available semiquantitative
quick immunological relaxin detecting test for dogs and
cats in the mare. Serums of ten mares (pony, saddle or draft) are used
for Witness Relaxin ® Test (Synbiotics Corporation, France): an
ELISA sandwich test. The sample is mixed with specific primary
antibodies, then this complex migrates on a membrane and is captured
by secondary antibodies. Positive reaction reveals a coloured band.
Proper migration on the membrane is confirmed by a second coloured
band (witness). Diagnosis and stage of pregnancy are assessed by
transrectal or abdominal ultrasonography. Sensibility and specificity
are determined and statistical significance is obtained by Fischer’s
exact test. Out of the 10 mares, 4 were non-pregnant and 6 were
pregnant over 100 days. No Witness Relaxin ® Test did show a
positive result, neither for pregnant nor for non-pregnant mares.
Sensitivity is 0% and specificity is 100%. Samples of the 6 pregnant
mares were sent to the Synbiotics laboratory for a classical ELISA,
but none showed a response for the antibodies used. Antibodies of the
Witness Relaxin ® Test have been used successfully in various species
(dog, cat, mice). Although equine relaxin has a similar structure with
two sub-units (A and B) and a comparable molecular weight, these
antibodies fail to recognize its sub-unit B. Further studies are required
to develop specific equine antibodies.
P253
Clinical Causes for Infertility in Jennets on “Planalto
Mirandês”
Quaresma, M 1 *, Payan-Carreira, RM 2
1Veterinary Teaching Hospital,; 2 CECAV; Univ. Trás-os-Montes and Alto
Douro, Vila Real, Portugal
A group of 24 jennets were reported by the local breeder’s association
to our Veterinary Teaching Hospital with complains of infertility.
Twenty-two animals belong to the breed “Asinina de Miranda”
(84,6%), a small portuguese breed of no more than 200 females
registered in the Book, and 4 were Miranda’s crossbreed (15,4%). The
group showed a wide ages distribution, ranging from 3 to more than
15 years old. The gynaecological evaluation of the jennets included
the reproductive anamnesis and examination of the external genitalia,
vaginoscopic and digital evaluation of the vagina and the evaluation
of the uterus and ovaries by transrectal palpation and ultrasonography.
The gynaecological examination detected six jennets having structural
anomalies: one with an imperforate hymen, two other animals with
severe hymenal constriction and two with cervical hypoplasia.
Another one evidenced a polyp in entrance of the uterine body.
Ultrasonographic examination evidenced bilateral granulosa cell
tumours in four of the jennets. It was also found a female with
multicystic uterus resembling “suisse cheese”, and isolated uterine
cysts in two of the females. In sixteen animals ultrasonographic
evaluation demonstrated an apparent normal ovarian activity, despite
that most of them being referred by owners as in anoestrus. It seems
that in many of those cases the owners were unable to detect oestrus.
Although the data presented here was collected in a relatively small
number of animals, it may reflect the high consanguinity that we tend
to observe in this breed due to the low number of animals available
for reproduction.