The presence of an additional fetal membrane and its function in the newborn guanaco ()

Merkt, H; Boer, Marjon A. de; Rath, Detlef; Schoon, H-A

doi:10.1016/0093-691x(88)90192-6

Cited by 10 publications

(3 citation statements)

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“…As regards the epidermal membrane of llamas, the morphological characteristics match the descriptions already made for llamas (Fowler & Olander 1990, Olivera 2002 and also for other members of the Camelidae family (Musa 1977, Merkt et al 1988. Based on the structural results it can be stated that this membrane has a mechanical role of protecting the internal surface of the fetal membranes as well as facilitating llamas' parturition.…”

Section: Discus Discus Discus Discus Discussion Sion Sion Sion Sionsupporting

confidence: 64%

The materno-fetal interface in llama (Lama guanicoe glama)

et al. 2007

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Samples from 9 llamas (28 through 36 weeks of gestation) were collected and fixed in 4% buffered paraformaldehyde (light microscopy) and in 2.5% buffered glutaraldehyde (transmission and scanning electron microscopy). The material was processed in paraplast and slides (5mm) were stained with HE, PAS, Masson-Trichrome, acid phosphatase and Perl's. The uteroferrin was immunolocalized. The results show that llama placenta is chorioallantoic, diffuse, folded and epitheliochorial, and the fetus is covered with an epidermal membrane. The trophoblast cells have variable morphology: cubic, rounded and triangular cells, with cytoplasm containing PAS-positive granules. Binucleated cells with large cytoplasm and rounded nuclei, as well as giant trophoblastic cells with multiple nuclei were also observed. Numerous blood vessels were observed beneath the cells of the uterine epithelium and around the chorionic subdivided branches. Glandular activity was shown by PAS, Perl's, and acid phosphatase positive reactions in the cytoplasm and glandular lumen, and by immunolocalization of the uteroferrin in the glandular epithelium. The uterine glands open in spaces formed by the areoles, which are filled by PAS-positive material. The llama fetus was covered by the epidermal membrane, composed of stratified epithelium, with up to seven layers of mono-, bi- or trinucleated cells. The high level of maternal and fetal vascularization surfaces indicates an intense exchange of substances across both surfaces. The metabolic activity shown in the uterine glands suggests an adaptation of the gestation to the high altitudes of the natural habitat of this species.

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Section: Discus Discus Discus Discus Discussion Sion Sion Sion Sionsupporting

confidence: 64%

The materno-fetal interface in llama (Lama guanicoe glama)

et al. 2007

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“…It is translucent and covers the whole foetus and is attached at all mucocutaneous junctions (Figure 1). It is suggested that its function is to lubricate the foetus and thus facilitate its delivery (Aba, 2014;Brown, 2000;Merkt, Böer, Rath, & Schoon, 1988;Smith et al, 1994;Whitehead, 2009).…”

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confidence: 99%

Macroscopic evaluation of the placenta of the alpaca (Vicugna pacos)

Meesters

Opsomer

Govaere

2019

Reprod Domestic Animals

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Macroscopic evaluation of the placenta is an essential post‐partum examination in the alpaca and can be of special interest in case of abortion, premature birth or stillbirth. Since there are not many reference values regarding macroscopic properties of normal alpaca placentas, a small descriptive study was conducted. Only placentae from normally foaling alpaca mares, giving birth to healthy crias, after a full‐term and uneventful gestation (±350 days; range 335–360 days) were taken into account (N = 11). Crias weighed (±SD) 7.7 ± 2.25 kg (range 5.5–10 kg), while the mean weight of the full‐term placentas was 0.8 ± 0.19 kg, that is 10% of the bodyweight of the crias. The weight of the allantoamnion and chorion was 0.2 ± 0.07 kg and 0.5 ± 0.13 kg, respectively. The umbilical cord length was 8.8 ± 2.84 cm, and the length of the pregnant and non‐pregnant uterine horns was 69.4 ± 12.77 cm and 54.5 ± 6.81 cm, respectively. The length of the corpus was 14.6 ± 4.68 cm, and the distance from the umbilicus to the corpus was 18.5 ± 6.13 cm. The tissue volume of the allantoamnion was 0.14 ± 0.079 L, and the chorionic volume was 0.37 ± 0.078 L. The surface area of the allantoamnion and the chorion was 87.6 ± 15.56 dm2 and 72.3 ± 9.28 dm2, respectively. All placentas had small calcifications either around the umbilical cord alone or around the umbilicus and blood vessels of the pregnant uterine horn. These measurements could be used to macroscopically evaluate alpaca placentas, although more research is needed to extend our knowledge of macroscopic evaluation of normal and abnormal placentas.

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“…Dieser Plazentationstyp erklärt die Notwendigkeitder zeiti-genKolostrumaufnahme derF ohlen postnatum, da siemit einer Hypogammaglobulinämie geborenw erden. Kameliden besitzen eine dritteEihaut fetalenUrsprungs,die denFetus umhüllt und bei derG eburts chnell einreißt (25). Die Plazentation istu md en 90.…”

Section: Gravidität Und Graviditätsdiagnoseunclassified

Aspekte der Reproduktionssteuerung bei Schaf und Ziege

Meinecke-Tillmann¹,

Meinecke²

2008

Tierarztl Prax Ausg G

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ZusammenfassungDie Kontrolle der Reproduktion bei kleinen Wiederkäuern spielt unter betriebswirtschaftlichen Gesichtspunkten eine wichtige Rolle. Dabei kommt der Beeinflussung der Saisonalität, der Zyklussteuerung im Hinblick auf die terminierte Besamung und der Beeinflussung der Nachkommenzahl die größte Bedeutung zu. Ziel der vorliegenden Analyse ist, basierend auf den neuen Erkenntnissen in der Reproduktionsphysiologie, international übliche Methoden im Bereich der Steuerung der Saisonalität, des Zyklus und der Ovulationsrate bei kleinen Wiederkäuern zu erläutern und einen kurzen Überblick über verschiedene Aspekte der medikamentös oder durch biologische Effekte beeinflussten Fortpflanzung bei diesen Spezies zu geben. Methodisch finden exogene Gestagene zur Zyklusinduktion oder -synchronisation und/oder Prostaglan - dinanaloga zur Beeinflussung der Lebensspanne des Gelbkörpers in Kombination mit Gonadotropingaben international breite Anwendung, doch wird über variable Fruchtbarkeitsergebnisse berichtet. Mögliche Gründe hierfür liegen unter anderem in Störungen in der Follikelentwicklung, dem Ausbleiben der Befruchtung, Beeinträchtigungen des embryonalen Überlebens und der vorzeitigen Gelbkörperregression oder sind spezies- oder rassebedingt. Um eine hohe Fertilität auch bei terminierter Besamung zu erreichen, konzentrieren sich die Anstrengungen weltweit derzeit darauf, verkürzte Behandlungsprotokolle und geeignete Dosierungen zu erarbeiten, die eine verbesserte Synchronisierung der Brunst und Ovulation unter Berücksichtigung des in Wellen erfolgenden Follikelwachstums ermöglichen. Arzneimittelrechtliche Vorschriften erschweren in Deutschland den Einsatz der kontrollierten Reproduktionstechniken.

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The presence of an additional fetal membrane and its function in the newborn guanaco ()

Cited by 10 publications

References 1 publication

The materno-fetal interface in llama (Lama guanicoe glama)

The materno-fetal interface in llama (Lama guanicoe glama)

Macroscopic evaluation of the placenta of the alpaca (Vicugna pacos)

Aspekte der Reproduktionssteuerung bei Schaf und Ziege

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