Pregnancy rates and gravid uterine parameters in single, twin and triplet pregnancies in naturally bred ewes and ewes after transfer of in vitro produced embryos

Grazul-Bilska, Anna T.; Pant, Disha; Luther, J. S.; Borowicz, P. P.; Navanukraw, Chainarong; Caton, J. S.; Ward, Marcy A.; Redmer, Dale A.; Reynolds, Lawrence P.

doi:10.1016/j.anireprosci.2005.06.013

Cited by 31 publications

(37 citation statements)

References 44 publications

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“…However, there is an overall reduction in placental size and fewer placentomes per conceptus. Placentome number per conceptus decreases from about 70 for singletons to about 40 in twins, and 28 and 22 in triplets and quadruplets, respectively (Alexander, 1964b;Rhind et al, 1980;Greenwood et al, 2000;Kaulfuss et al, 2000;Pant et al, 2003;Dwyer et al, 2005;Grazul-Bilska et al, 2006). In studies in which total placentome numbers were relatively high, maximum occupancy of caruncles was observed in pregnancies with twins, while for litters in which total placentome numbers were relatively low, maximal occupancy of caruncles was found to be highest in ewes with triplets ( Figure 6).…”

Section: Roles Of the Conceptus And Ewe In Foetal Growthmentioning

confidence: 99%

Litter-size-dependent intrauterine growth restriction in sheep

Gootwine

Spencer

Bazer

2007

Animal

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Regulation of foetal development in sheep depends on interactions between the intrinsic capacity of the foetus for growth and the maternal environment. Lambs born in multi-foetus litters have relatively small placentae with fewer cotelydons, and lower birth weights. Litter-size-dependent intrauterine growth restriction (IUGR) is evident at mid gestation when metabolic needs of the conceptus are moderate, and overnutrition of ewes with multiple foetuses does not promote growth of their foetuses to the size of singletons. Those observations suggest that placental and conceptus growth in multi-foetus pregnancies is reprogrammed at mid gestation by an as yet undefined mechanism to attenuate foetal growth. This may protect the foetus from severe nutritional insult during late gestation, when its daily growth rate is at a maximum. In that way, lambs born in large litters with relatively lower birth weights may not experience the long-term physiological insults that can be observed in small lambs born to undernourished ewes.

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Section: Roles Of the Conceptus And Ewe In Foetal Growthmentioning

confidence: 99%

Litter-size-dependent intrauterine growth restriction in sheep

Gootwine

Spencer

Bazer

2007

Animal

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“…It is stated that IGF shows synergetic action with FSH and they stimulates the steroid production and oocyte maturation (O'Brien et al, 1997). Grazul-Bilska et al (2006) found that adding EGF to medium could increase the cleavage rates of sheep embryos than the control group (59% vs. 78%). The cleavage rate of our study was 69.69%.…”

Section: Discussionmentioning

confidence: 99%

“…In vivo sheep embryo production consists from these steps: Oestrus synchronization and superovulation of the donors, artificial insemination or natural breeding, collecting embryos from the uterus by surgical flushing technique and finding the embryos under microscopic observation (Garcia et al, 2006). Although, there are many studies on cryopreservation of cattle embryos (Gasparrini, 2002;Hasler et al, 1987;Kaidi et al, 1999), studies on sheep embryos are still rare (Fowler and Toner, 2005;Grazul-Bilska et al, 2006;Isachencko et al, 2003), little studies had been done about sheep embryos and a common cryopreservation method for sheep has not yet been developed (Fowler and Toner, 2005). The survivability rates of cryopreserved embryos show differences between researchers.…”

Section: Araştırma Makalesimentioning

confidence: 99%

Effect of Different Cooling Rates on Embryo Survivability and Pregnancy Rates in Freezing Sheep Embryos

Öztürk¹,

Demır²,

Arıcı³

et al. 2016

İstanbul Üniv. Vet. Fak. Derg.

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In the first stage of the study, oocytes obtained from ovaries from abbatoir (n=2990) were incubated in maturation medium for 24 h. The maturated oocytes were left for in vitro fertilization (IVF) for 20 hours. The cleavaged embryos (n=1305) were left for in vitro culture (IVC) for six days. Then morula-blastocyst stage embryos divided randomly in three groups (Grup I: 0.5°C/min, Grup II: 0.8°C/min, Grup III: 1°C/min). Embryos in each group (n=50) were frozen at different cooling rates in 1.5 M ethylene glycol containing freezing medium. As a result, 0.5°C/min cooling rate group was found as the most successful group (P<0.05). In the second stage of the study, in vivo embryos (morula-blastocyst) derived from donor sheep were frozen at 0.5 °C/min. Frozenthawed nineteen embryos were transferred to hormonally pretreated seventeen recipients. At the 60 th day of the transfer, three recipients were diagnosed as pregnant and one of them had twins. One of the three recipients gave birth and two sheeps had early embryonic loss are observed in the later ultrasound scanning. In the study, 0.5°C/min cooling rate in the slow freezing of sheep embryos was found out to be more successful cooling rates and pregnancy following a healthy lambing is achieved. Özet Koyun Embriyolarının Dondurulmasında Farklı Soğutma Hızlarının Embriyoların Canlılığı ve Gebelik Oranları Üzerindeki EtkisiÇalışmanın ilk bölümünde, mezbahadan sağlanan ovaryumlardan kazanılan oositler (n=2990) olgunlaştırma medyumu içerisinde 24 saat süreyle olgunlaştırıldı. Ardından, 20 saat süreyle İn Vitro Fertilizasyona (İVF) bırakıldılar. Yarıklanma gösteren embriyolar (n=1305), Sentetik Ovidukt Fluid (SOF) medyumu içerisine alınarak altı gün süresince İn Vitro Kültüre (İVK) bırakıldılar. İVK sonrası elde edilen morula-blastosist aşamasındaki embriyolar rastlantısal şekilde üç farklı dondurma hızı grubuna eşit olarak ayrıldılar (Grup I: 0,5 °C /dk, Grup II: 0,8 °C /dk, Grup III: 1 °C /dk). Her bir gruptaki embriyolar (n=50), 1,5 M etilen glikol bulunan dondurma medyumu içerisinde farklı soğutma hızlarında donduruldu. Sonuçta 0,5 °C/dk soğutma hızının en başarılı grup olduğu belirlendi (P<0,05). Çalışmanın ikinci bölümünde, verici koyunlardan elde edilen in vivo embriyolar (Morula-Blastosist) çalışmanın birinci bölümünde bulunan en başarılı soğutma hızı (0,5 °C/dk) ile soğutularak donduruldu. Dondurulan 19 adet embriyo hormonel olarak hazırlanmış 17 alıcı koyuna transfer edildi. Transfer sonrası 60. günde yapılan ultrason muayenesinde üç adet koyunda gebeliklere ait embriyonik keseler gözlendi ve bu koyunlardan birinde de ikiz gebelik saptandı. Gebe koyunlardan bir tanesinde doğum gerçekleşti; diğer iki koyunda ise ileriki dönemde yapılan ultrason muayenesinde gebeliklerin sonlandığı gözlendi. Çalışma sonucunda, koyun embriyolarının dondurulması sırasında 0,5°C/dk soğutma hızının en başarılı hız olduğu ve bu yöntemle dondurulan embriyoların transferinden de gebelik elde edilebildiği saptandı.

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“…maternal gravid uterine free weight to be maintained). Previous studies have indicated that the total gravid mass at term is in the range of 18Á22 kg (Rattray et al 1974;Grazul-Bilska et al 2006;Kenyon et al 2007). The duration of the grazing period within each paddock was dependent on herbage mass and ewe liveweight change previously measured.…”

Section: Experimental Designmentioning

confidence: 99%

“…In support of this, Forbes (1968) reported that rumen volume was reduced in the last 5 weeks of pregnancy. At term, the gravid uterus weight of a triplet-bearing ewe can weigh up to 22 kg (Grazul-Bilska et al 2006;Kenyon et al 2007). The results of Morris & Kenyon (2004) suggest multiple-bearing ewes may fail to consume their theoretical nutritional requirements in late pregnancy under unrestricted perennial ryegrass/white clover grazing conditions (Morris & Kenyon 2004;Nicol & Brookes 2007).…”

Section: Introductionmentioning

confidence: 99%

Does early pregnancy nutrition affect the performance of triplet-bearing ewes and their progeny to weaning?

Kenyon

Pain

Hutton

et al. 2011

New Zealand Journal of Agricultural Research

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Triplet-bearing ewes were offered one of three pastoral-based nutritional regimens from day 21 to day 50 of pregnancy (P21 to P50): su3b-maintenance (SM), maintenance (M) or ad lib (AD). From P50 to term, ewes were managed with the aim of ensuring total liveweight increased with expected gravid uterus mass. AD ewes were heavier (PB0.05) and had greater (PB0.05) body condition scores than both SM and M ewes at P50, with the latter two treatments not differing (P ! 0.05). Ewe nutritional treatment had no effect (P!0.05) on lamb birthweight, indices of colostrum uptake or lamb weaning weight. In conclusion, the data suggest that the nutrition of triplet-bearing ewes in the early pregnancy period can be controlled without any deleterious effects to offspring. However, it is important to note that in mid to late pregnancy the ewes were managed to ensure gravid uterus development was not impeded.

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Pregnancy rates and gravid uterine parameters in single, twin and triplet pregnancies in naturally bred ewes and ewes after transfer of in vitro produced embryos

Cited by 31 publications

References 44 publications

Litter-size-dependent intrauterine growth restriction in sheep

Litter-size-dependent intrauterine growth restriction in sheep

Effect of Different Cooling Rates on Embryo Survivability and Pregnancy Rates in Freezing Sheep Embryos

Does early pregnancy nutrition affect the performance of triplet-bearing ewes and their progeny to weaning?

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