Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias

16 t h International Congress on Animal Reproduction
74 Poster Abstracts
semen samples used on artificial insemination programs in ovine
herds.
P138
The End of Breeding Season in Subtropical Female Goats
Results From the Development of Refractoriness to
Winter Short Days
Delgadillo, JA 1 *; Aguilar, J 1 ; Malpaux, B 2
1Centro de Investigación en Reproducción Caprina, Universidad Autónoma
Agraria Antonio Narro, Torreón, Coahuila, México; 2 Physiologie de la
Reproduction et des Comportements, UMR 6175 INRA-CNRS-Université de
Tours-Haras Nationaux, Nouzilly, France
This study was carried out to determine if the end of the breeding
season of local female goats from subtropical Mexico results from
refractoriness to the stimulatory effect of short days of winter or to
the inhibitory effect of increasing day length following the winter
solstice. Does were ovariectomized and treated with a subcutaneous
implant constantly releasing estradiol-l7 ß (OVX+E). The control
group (n = 6) remained in open sheds under natural day length. The
experimental group (n = 6) was placed in a light-proof building and
exposed to constant short days (10 hours of light by day) from the
winter solstice. LH plasma concentrations were measured twice a
week. The seasonal decrease in LH secretion, indicative of the end of
the breeding season, was defined as the first of three consecutive
samples with LH concentrations lower than 1 ng/ml. The seasonal
decrease in LH secretion did not differ (P > 0.05) between
experimental (February 4 + 10 days) and control (February 3 + 5
days) groups. These results allow us to conclude that, as in temperate
latitudes, the end of the breeding season in female goats raised in a
subtropical latitude is not driven by winter increasing day length,
rather it appears to result from short day refractoriness. This suggests
the implication of an endogenous circannual rhythm in regulating
seasonal changes in reproduction in subtropical latitudes.
Supported by CONACyT grant (28420N).
P139
Effect of dietary supplement of phytoestrogens on
thyroid hormones, steroid production and localization of
carbonic anhydrase in testis, efferent ductules and
thyroid gland of male goat kids
Ekstedt, E 1 *; Holm, L 1 ; Ridderstråle, Y 1 ; Selstam, G 2 ; Madej, A 1
1Department of Anatomy, Physiology and Biochemistry, Swedish University of
Agricultural Sciences, Box 7011 S-750 07 Uppsala, Sweden; 2 Department of
Molecular Biology, University of Umeå, 90187 Umeå, Sweden
Exposure of xenoestrogens to humans and animals is an increasing
concern due to their effects on reproduction. Phytoestrogens are nonsteroidal
substances in many plants with capacity to bind to oestrogen
receptors (ER). Presence of ER in the efferent ductules of the mature
male goat indicates the importance of estrogens for male
reproduction, which in turn have an effect on carbonic anhydrase
(CA) activity (Zhou et al., 2001). The present study was undertaken to
investigate whether a low addition of phytoestrogens to a normal diet
affects thyroid hormone secretion, the establishment of testosterone
production and histochemical localization of CA in testis, efferent
ductules and thyroid gland during puberty in male goat kids. Four male
goat kids were given a standard diet and 3 were given an addition of 3 - 4
mg phytoestrogens/kg body weight in tablets containing genistein,
daidzein, biochanin and formononetin. The treatment commenced at 3
months of age and continued until slaughter at 6 months of age. Plasma
testosterone, oestrone sulphate, total and free triiodothyronine (T 3 ) and
thyroxin (T 4 ) were measured weekly. Testosterone and cyclic AMP were
measured in testicular tissue and CA was localized histochemically in
thyroids and reproductive organs. After four weeks of treatment, total T 3
concentrations were significantly higher in the phytoestrogen treated
animals than in the control ones (2.3 ± 0.3 vs. 1.2 ± 0.2 nmol/l, P < 0.01).
Plasma testosterone concentrations at week 7 were significantly (P <
0.05) higher in the phytoestrogen treated animals than the control ones
(37.5 ± 6.0 vs. 19.1 ± 5.2 nmol/l). Free T 3 concentrations in kids exposed
to phytoestrogens were significantly higher than in control animals during
week 8 and 9 of the experiment. At the end of the experiment plasma
testosterone concentrations were slightly lower in treated goats,
testosterone and cyclic AMP levels were lower in testicular tissue. Strong
staining for CA activity was present in testicular capillaries, nuclei
and apical membranes of the non-ciliated cells of the efferent
ductules. The thyroid gland showed strong CA activity in the
basolateral membranes of the epithelium. No difference was shown
between groups. In conclusion, the exposure of male goat kids to low
doses of phytoestrogens has an impact on the hormonal changes
during puberty as well as the content of cyclic AMP in the testis, but
did not alter CA localization in thyroids or reproductive organs.
This study was supported by Formas
P140
Efficiency of transabdominal ultrasonography in
pregnancy diagnosis during late embryonic and early
fetal stages of pregnancy in Konya Merino ewes
Erdem, H 1 *, Saribaym MK 2 , Tekeli, T 1
1Obstetrics and Gyneacology, Selcuk University Faculty of Veterinary
Medicine, Turkey; 2 Obstetrics and Gyneacology, Mustafa University Faculty
of Veterinary Medicine, Turkey
Objective of this study was to evaluate the efficiency of location (right
ingiunal region [RIR] or left ingiunal region [LIR]) of transabdominal
ultrasonography to determine pregnancy and number of embryo/fetus
during late embryonic and early fetal stages of pregnancy in Konya
Merino ewes. Eighty-four ewes were diagnosed as pregnant 34 days
after mating by transrectal ultasonograhy. Of these ewes, 45 had
single embryo and 39 had twin embryos. On days 34 and 50, these
ewes were again examined by RIR and LIR transabdominal
ultasonography. The results were compared with transrectal
ultrasongraphy and lambing records. On day 34, 62 % (28/45) and
64% (29/45) of single pregnancies and 33 % (13/39) and 28 %
(11/39) of twin pregnancies could be detected through RIR and LIR
transabdominal ultrasonography, respectively. On day 50, 88 %
(40/45) and 91 % (41/45) of single and 53 % (21/39) and 46 %
(18/39) of twin pregnancies were detected through RIR and LIR
transabdominal ultrasonography, respectively. Data were analysed by
paired simple t-test and there were no significant differences between
the days (day 34 vs day 50) and locations of examinations (RIR vs
LIR). In conclusion, twin pregnancies can not be effectively
diagnosed through transabdominal ultasonography during the first 50
days of pregnancy. However, when detecting number of embryo/fetus
is not important, pregnancy diagnosis can be performed with this
method starting on day 34.
P141
Melatonin-based induction of cyclicity in intensive dairy
(Awassi) flocks
Faigl, V 1 *; Keresztes, M 1 ; Árnyasi, M 2 ; Kulcsár, M 1 ; Nagy, S 3 ; Szenci, O 1 ;
Cseh, S 1 ; Huszenicza, G 1
1Faculty of Veterinary Science, Szent István University, Budapest, Hungary;
2Faculty of Agricultural Sciences, University of Debrecen, Hungary; 3 Awassi
Corporation, Bakonszeg, Hungary
Our aim was to compare three different cycle induction /
synchronisation protocols used out of the breeding season in Awassi
ewes. In the first experiment (Exp.1) 85 autumn lambing ewes of a
commercial dairy farm were used. Milk progesteron (P4) or fecal
gestegen metabolits were determined 3 times 7 days apart on d0, d7,
d13 (Exp.1 d0:10 th Febr). Gest group was treated in April with
gestagen sponge(d56-d70)+600IU eCG(d70). Mel+Gest group was
implanted with melatonin (Mel, Melovin®, CEVA, Libourne, France)
on d0 and synchronised as Gest group 56 days later. Mel+GPG
animals were treated with Mel (d0) and synchronised with
GnRH(d63)–PGF2α(d70)–GnRH(d72). Ewes were inseminated twice
(fix AI) and were introduced to rams 14 days later. Individual P4
profile was followed from d45 to d99. Pregnancy associated
glucoprotein was assayed on d99 and d133. Date of conception was