Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias
Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias
Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias
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16 t h International Congress on Animal <strong>Reproduction</strong><br />
214 Poster Abstracts<br />
and preoovulatory follicles number <strong>in</strong> the exposed group (p< 0.04)<br />
were observed. Ambient air pollution seems to affect selectively the<br />
ovarian follicles, <strong>de</strong>creas<strong>in</strong>g the antral follicle number and not<br />
affect<strong>in</strong>g the pool of immature follicles (small and grow<strong>in</strong>g). These<br />
results suggests that changes <strong>in</strong> follicle maturation could be one of the<br />
mechanisms <strong>in</strong>volved <strong>in</strong> reduced fertility <strong>in</strong> female mice exposed to<br />
ambient levels of air pollution.<br />
Poster 25 - Developments <strong>in</strong> Susta<strong>in</strong>able Animal<br />
Production and <strong>Reproduction</strong><br />
P565<br />
Reproductive efficiency of F1 Holste<strong>in</strong> x Zebu crossed<br />
cows raised <strong>in</strong> pasture conditions of central part of Brazil<br />
Ruas, JRM 1 *, Silva, MA 2 , Borges, AM 3 , Carvalho, BC 4 , Ferreira, IC 5 , Valente,<br />
DB 5 , Menezes, GCC 5 , Matos, CRA 5<br />
1Research Department, M<strong>in</strong>as Gerais Agricultural Research Corporation-<br />
EPAMIG, Brazil; 2 Animal Science Department, Faculty of Veter<strong>in</strong>ary<br />
Medic<strong>in</strong>e-UFMG, Brazil; 3 Veter<strong>in</strong>ary Cl<strong>in</strong>ics and Surgery, Faculty of<br />
Veter<strong>in</strong>ary Medic<strong>in</strong>e-UFMG, Brazil; 4 MG Agricultural Research Corporation-<br />
EPAMIG, Brazil; 5 Faculty of Veter<strong>in</strong>ary Medic<strong>in</strong>e-UFMG, Brazil<br />
Dur<strong>in</strong>g the last <strong>de</strong>ca<strong>de</strong> significant <strong>in</strong>crease <strong>in</strong> milk production and<br />
expressive reduction <strong>in</strong> reproductive efficiency of herds of specialized<br />
cows <strong>in</strong> Brazil were observed. Intensive genetic selection for<br />
maximiz<strong>in</strong>g milk production has resulted <strong>in</strong> metabolic and hormonal<br />
modifications that negatively affected milk production. Today the<br />
Brazilian’s great challenge of milk production systems is to search for<br />
adapted genotypes that show high productive and reproductive<br />
efficiency <strong>in</strong> pastures conditions, high profitability and preserve the<br />
environment This research evaluated the reproductive efficiency of<br />
243 F1 Holste<strong>in</strong> x Zebu crossed cows raised <strong>in</strong> pasture conditions of<br />
the central part of Brazil <strong>in</strong> the Experimental Research Center of<br />
EPAMIG (M<strong>in</strong>as Gerais Agricultural Research Corporation). The<br />
cows dur<strong>in</strong>g the summer season are ma<strong>in</strong>ta<strong>in</strong>ed <strong>in</strong> pastures of<br />
Brachiaria <strong>de</strong>cumbens and Brachiaria brizantha and dur<strong>in</strong>g the dry<br />
season lactat<strong>in</strong>g cows are additionally fed corn silage and sugar cane.<br />
Mechanic milk<strong>in</strong>g with cow’s calf presence and natural mat<strong>in</strong>g are<br />
used <strong>in</strong> the herd. First mat<strong>in</strong>g average (24 months), cow average age<br />
(33.6 months) and cow average weight at first calv<strong>in</strong>g (451.5kg) were<br />
consi<strong>de</strong>red satisfactory s<strong>in</strong>ce these cows were raised <strong>in</strong> pasture<br />
conditions. Cow body weight <strong>in</strong>creased up to fourth calv<strong>in</strong>g<br />
suggest<strong>in</strong>g these animals did not reach the adult body weight yet.<br />
Milk production average of 2,773.1kg was very high <strong>in</strong> comparison to<br />
national milk production average 1,350.0kg (Embrapa – CNPGL,<br />
2006). Days open averages were, respectively, equals to 163.7, 96.0,<br />
88.4 and 70.6 for first, second, third and fourth calv<strong>in</strong>g cows.<br />
Productive efficiency can be evaluated by kilogram of milk / calv<strong>in</strong>g<br />
<strong>in</strong>terval ratio but days open that is a reproductive trait has an effective<br />
effect on herd productive efficiency. The results suggest a great ability<br />
of F1 Holste<strong>in</strong> x Zebu cows to adapt to pasture conditions and to show<br />
high reproductive and productive efficiency <strong>in</strong> this production<br />
systems. Factors related to animal behavior and to mechanic milk<strong>in</strong>g<br />
adaptation should be consi<strong>de</strong>red <strong>in</strong> further studies.<br />
Poster 26 - Trends <strong>in</strong> Research, Care and Teach<strong>in</strong>g of<br />
<strong>Reproduction</strong><br />
P566<br />
Scann<strong>in</strong>g Electron Microscopic (SEM) analyses of the<br />
trophoblast of the term placenta of the Asian elephant<br />
(Elephas maximus)<br />
Lo<strong>de</strong>rstedt, S. 1 ; Hoffmann, A. 1 ; Eulenberger, K. 2 ; Flügger, J. 3 ; Seeger, J. 1<br />
1Institute of Veter<strong>in</strong>ary Anatomy, Department of Histology and Embryology,<br />
Faculty of Veter<strong>in</strong>ary Medic<strong>in</strong>e, University of Leipzig, An <strong>de</strong>n Tierkl<strong>in</strong>iken 43,<br />
04103 Leipzig; 2 Zoological Gar<strong>de</strong>n Leipzig GmbH, Pfaffendorfer Straße 29,<br />
04105 Leipzig; 3 Zoo Hagenbeck Hamburg GmbH, Lokstedter Grenzstraße 2,<br />
22509 Hamburg-Stell<strong>in</strong>gen<br />
Cognitions about structure and physiology of the Elephant placenta<br />
are rare. The <strong>de</strong>tailed characterization of the epithelial layer of the<br />
chorion on different locations is poorly un<strong>de</strong>rstood. Investigation with<br />
ultrastructural procedures, scann<strong>in</strong>g electron microscopic (SEM)<br />
analyses are the first f<strong>in</strong>d<strong>in</strong>gs to <strong>in</strong>vestigate the morphological<br />
features of the fetale membrane of the placenta <strong>in</strong> the Asian elephant<br />
(Elephas maximus).<br />
We used 3 term placentas (Zoological Gar<strong>de</strong>n Leipzig, Zoo<br />
Hagenbeck Hamburg) and selected different sites of the placental<br />
band and the extra placental Allantochorion.<br />
The placental band has a sponge like surface, and consists of fetal<br />
lamellae enclos<strong>in</strong>g maternal blood vessels. The lamellae are covered<br />
from the cytotrophoblast. The trophoblast cells show surface<br />
modifications, like microvilli and mikroplicae. The fetal capillaries<br />
are located directly un<strong>de</strong>rneath the cytotrophoblast and tend to <strong>in</strong>va<strong>de</strong><br />
the epithelium. In some locations there are less than 2µm between<br />
basallam<strong>in</strong>ae of maternal and fetal <strong>in</strong>traepithelial capillaries. In none<br />
of the <strong>in</strong>vestigated specimens the placental bor<strong>de</strong>r has been reduced.<br />
There is always a narrow trophoblastic cytoplasm band <strong>in</strong> between.<br />
Microscopically the placental band can be divi<strong>de</strong>d <strong>in</strong> to two portions.<br />
The apical, towards the uterus, and the basal, towards the fetus. The<br />
apical layer is dispersed. Between the fetal, placental lamellae, blood<br />
cells and amorphic material are located. The surface of the basal part<br />
of the placental band is very <strong>de</strong>nse. Fetal lamellae gett<strong>in</strong>g <strong>in</strong> direct<br />
contact with maternal capillaries. Free blood cells, like <strong>in</strong> the apical<br />
part can not be found. Maternal blood vessels are surroun<strong>de</strong>d from<br />
thickened basallam<strong>in</strong>ae. There is a dist<strong>in</strong>ct difference between the<br />
basallam<strong>in</strong>ae of ematernal and fetal blood vesels. It must be proposed,<br />
that the trophoblast cells are erod<strong>in</strong>g the maternal basallam<strong>in</strong>ae, and<br />
the endothelial cells are produc<strong>in</strong>g even more collagenic material to<br />
keep the lam<strong>in</strong>ae <strong>in</strong>tact.<br />
The chorionic surface is structured, and chorionic villi can be shown<br />
entirely. The SEM analyses revealed a cobblestone-like architecture<br />
of the epithelial cells, wich are covered with microvilli and<br />
microplicae themselve. Surpris<strong>in</strong>gly, the f<strong>in</strong>d<strong>in</strong>gs of <strong>in</strong>traepithelial<br />
capillaries <strong>in</strong>tend the trophoblast cells presume an nutrient exchange<br />
also outsi<strong>de</strong> of the placental band with her gross functional<br />
metabolism.<br />
This study revealed some unknown and <strong>in</strong>terest<strong>in</strong>g features of the<br />
epithelial layer of the chorion <strong>in</strong> the placenta of an Asian Elephant.<br />
Perhaps, with a <strong>de</strong>tailed knowledge of the morphology of the<br />
epithelium we convey an better un<strong>de</strong>rstand<strong>in</strong>g of functional cohesions<br />
of elephant placentation.<br />
Acknowledgements<br />
We are extremley gratful to Dr. M. Flügger of the Zoo Hagenbeck<br />
Hamburg and also Prof. K. Eulenberger, Dr. J. Junhold and Mrs.<br />
Bachmann of the Zoological Gar<strong>de</strong>n Leipzig for their cont<strong>in</strong>ued<br />
<strong>in</strong>terest <strong>in</strong> this <strong>in</strong>vestigation and for their practical help <strong>in</strong> gather<strong>in</strong>g<br />
samples.