Multiple Ovulation and Embryo Transfer in Hill Ewes: Effects of Mating System on Embryo Quality, and its Relationship With Pregnancy Rates

A breed improvement programme has been initiated at both ADAS Redesdale (Scottish Blackface) and ADAS Pwllpeiran (Welsh Mountain) to improve carcass conformation of hill ewes. At each site a nucleus flock of 60 ewes has been established and this is being replicated using multiple ovulation and embryo transfer (MOET). The project provides an opportunity to investigate factors affecting the success of MOET under field conditions with an unusually large population of animals maintained under a common management and environment at each site. The current results relate to the effect of mating system on embryo quality, and the relationships between embryo quality and embryo survival.

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An evaluation of the success of MOET in two breeds of hill sheep maintained under normal systems of hill flock management

Animal Science ◽

10.1017/s1357729800050931 ◽

1999 ◽

Vol 69 (2) ◽

pp. 367-376 ◽

Cited By ~ 8

Author(s):

F. Bari ◽

M. Khalid ◽

W. Haresign ◽

B. Merrell ◽

A. Murray ◽

...

Keyword(s):

Recovery Rate ◽

Embryo Quality ◽

Survival Rates ◽

Negative Relationship ◽

Embryo Survival ◽

Factors Affecting ◽

Embryo Recovery ◽

Multiple Ovulation ◽

Middle Range ◽

The Mean

AbstractThis study was undertaken to investigate factors affecting the success of multiple ovulation and embryo transfer (MOET) in Scottish Blackface (no. = 120) and Welsh Mountain (no. = 120) ewes, over a period of 2 years using a laparoscopic procedure for both embryo recovery and transfer. Superovulation was induced with ovine FSH, with 98 to 100% of ewes of both the breeds responding to the treatment. The overall mean superovulatory responses were 15⋅0 (s.e. 0⋅8) and 12⋅5 (s.e. 0⋅7) for Scottish Blackface and 15⋅3 (s.e. 0⋅9) and 12·8 (s.e. 0⋅8) for Welsh Mountain ewes in years 1 and 2, respectively. However, there was a wide degree of variation in superovulatory responses within each breed, with a range of 3 to 29 in Scottish Blackface and 1 to 40 in Welsh Mountain ewes. The mean embryo recovery rate was 71⋅9 (s.e. 3⋅5) % and 69⋅6 (s.e. 3⋅4) % for Scottish Blackface and 57⋅5 (s.e. 4⋅1) % and 60⋅6 (s.e. 3⋅6) % for Welsh Mountain ewes in years 1 and 2, respectively. The mean number of embryos recovered from Welsh Mountain ewes was significantly (P < 0⋅05) lower than that from Scottish Blackface ewes in both years. The lower mean number of embryos recovered in year 2 for both breeds was entirely a reflexion of the lower superovulatory responses in year 2. A significant (P < 0⋅001) relationship was observed between superovulatory response and the number of embryos recovered for both breeds. Some 77% and 72% of Scottish Blackface ewes and 65% and 73% of Welsh Mountain ewes yielded four or more transferable embryos in years 1 and 2, respectively. Neither the mean number nor the mean percentage of transferable embryos per donor ewe differed between breeds or years. A significant (P < 0⋅001) negative relationship was observed between the time of onset of oestrus and both superovulatory response and number of embryos recovered in Scottish Blackface ewes only. Embryo quality was affected by the time of onset of oestrus. In both breeds, the highest proportion of grade 1+2 embryos and the lowest proportion of unfertilized/degenerate embryos occurred in the middle range time, with a reduction in the proportion of grade 1+2 embryos in ewes that came into oestrus either early <19 h) or late (>30 h) after sponge removal. Only one embryo was transferred to each recipient and the embryo survival rates were 76⋅8% and 74⋅6% (Scottish Blackface), and 69⋅6% and 87⋅3% (Welsh Mountain) for years 1 and 2, respectively. Overall the results of this study suggest that MOET is as successful in hill ewes as has been reported for lowland breeds, even without making any major concessions to their hill status.

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An evaluation of MOET in Suffolk sheep

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600024296 ◽

1993 ◽

Vol 1993 ◽

pp. 103-103 ◽

Cited By ~ 2

Author(s):

W S Dingwall ◽

W A C McKelvey ◽

J Mylne ◽

G Simm

Keyword(s):

Embryo Transfer ◽

Large Scale ◽

Genetic Progress ◽

Transfer Rates ◽

Multiple Ovulation ◽

Lean Growth ◽

Improvement Programme ◽

Breed Improvement ◽

Invasive Techniques ◽

Suffolk Sheep

SAC Edinburgh has a long established breed improvement programme to increase the lean growth rate of Suffolk sheep. Studies commenced in 1989 to evaluate the extra genetic gain which could be achieved through the application of multiple ovulation-embryo transfer (MOET). Theoretical studies show that rates of genetic progress in sheep could be increased by 100% through use of MOET to increase selection intensity amongst females and reduce female generation intervals (Smith, 1986). However, to achieve these levels of improvement requires good embryo transfer rates (10 progeny per donor) at 6 to 8 months of age. Smith (1986) identified that current transfer rates fell well short of these required by his calculations. Given that minimally invasive techniques for the recovery and transfer of embryos by laparoscopy are available (McKelvey, Robinson and Aitken, 1985a), the main impediment to achievement of the embryo transfer rates required is the low and variable superovulatory response in donor ewes. Previous studies investigating superovulatory drugs to increase the ovulation rate of donor ewes in MOET programmes identified Ovagen (Immuno-Chemical Products), as the most potent product (Dingwall, Fernie, FitzSimons and McKelvey, 1991). This trial reports the use of Ovagen in a large scale MOET programme applied to Suffolk ewes.

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Multiple Ovulation and Embryo Transfer in Hill Ewes

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600026350 ◽

1994 ◽

Vol 1994 ◽

pp. 88-88

Author(s):

W. Haresign ◽

B. Merrell ◽

R.I.W.A. Richards

Keyword(s):

Embryo Transfer ◽

Genetic Improvement ◽

Theoretical Studies ◽

Base Population ◽

Multiple Ovulation ◽

Female Line ◽

Improvement Programme ◽

Breed Improvement ◽

The Uk ◽

Selection Of

A breed improvement programme has been initiated at both ADAS Redesdale (Scottish Blackface) and ADAS Pwllpeiran (Welsh Mountain) to improve carcass conformation of hill ewes. From a base population of 1100 Welsh Mountain and 1600 Scottish Blackface ewes, nucleus flocks of 60 ewes have been established. Selection of ewes into the nucleus flock at each site has been based on their ability to consistently produce wether lambs crops with good conformation and above average carcass weights when selected for slaughter at a fat class 2/3L. The next objective is to replicate these ewes through multiple ovulation and embryo transfer (MOET) since theoretical studies (Smith, 1986) indicate that this can substantially increase the rates of genetic improvement through the female line. However, to date little work has been conducted to determine whether this technology can be successfully applied to hill sheep maintained in harsh hill environments in the UK, and this formed the basis of the current study.

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Factors Affecting Embryo Recovery Rate, Quality, and Diameter in Andalusian Donkey Jennies

Animals ◽

10.3390/ani10111967 ◽

2020 ◽

Vol 10 (11) ◽

pp. 1967

Author(s):

J. Dorado ◽

M. Bottrel ◽

I. Ortiz ◽

M. Díaz-Jiménez ◽

B. Pereira ◽

...

Keyword(s):

Developmental Stage ◽

Embryo Transfer ◽

Recovery Rate ◽

Embryo Quality ◽

Donor Age ◽

Successive Cycle ◽

Assisted Reproductive Technique ◽

Factors Affecting ◽

Embryo Recovery ◽

Starting Point

Embryo transfer and the vitrification of embryos could be used for the conservation and recovery of endangered donkey breeds. It is important to develop techniques that optimize recovery rates and the cryotolerance of donkey embryos. This study evaluates factors affecting the recovery rate, quality, and diameter of embryos obtained from donor jennies as a starting point for the use of vitrification and embryo transfer in the conservation of the Andalusian donkey. A total of 100 embryos were recovered out of 124 estrous cycles (80.6%). The donor jenny affected the rates of positive flushings (PFR; p = 0.040) and embryo recovery (ERR; p < 0.05) as well as embryo quality (p = 0.004). ERR was also affected by the number of flushings (p < 0.001), donor age (p < 0.05), successive cycle within donor (p < 0.001), and jacks (p < 0.05). Number of flushings (p < 0.001) and jack (p < 0.05) had a significant effect on PFR, whereas the day of flushing influenced the developmental stage (p < 0.001), embryo quality (p < 0.05), and diameter of embryos (p < 0.001). The number of flushings significantly influenced the diameter (p = 0.038) and embryo developmental stage (p = 0.001), whereas the developmental stage was statistically different between herds (p = 0.020). The factors influencing the success of this assisted reproductive technique were donor jenny, donor age, successive cycle within donor, day of flushing, number of flushings, and jack. The identification of these key points is crucial to achieve a higher efficiency of embryo transfer and vitrification processes, before considering their application in the conservation of endangered donkey breeds.

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Comparison of MOET in Texel ewe lambs and yearling ewes

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600026325 ◽

1994 ◽

Vol 1994 ◽

pp. 85-85

Author(s):

B.T. Wolf ◽

I. McDougall

Keyword(s):

Embryo Transfer ◽

Embryo Quality ◽

Survival Rates ◽

Genetic Progress ◽

Generation Interval ◽

Ewe Lambs ◽

Multiple Ovulation ◽

One Year

Combined multiple ovulation and embryo transfer (MOET) from ewe lambs could significantly increase the rate of genetic progress in sheep improvement programmes (Smith, 1986). The benefits arise from a combination of an increased number of progeny from superior females and a reduction in the generation interval. Maximum success requires that the procedures are carried out in ewe lambs at six to seven months of age to produce offspring when the donors are one year old. Previous studies suggest that embryo quality and survival rates are naturally lower in ewe lambs and are likely to limit the success of MOET in this class of animal (Quirke and Hanrahan, 1977; McMillan and McDonald, 1985). The present study was undertaken to evaluate the potential of recently developed superovulatory procedures for application to ewe lambs.

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The use of multiple ovulation, embryo cryopreservation and embryo transfer techniques to facilitate movement of genetic material between countries

Journal of the Hellenic Veterinary Medical Society ◽

10.12681/jhvms.15378 ◽

2018 ◽

Vol 53 (3) ◽

pp. 237

Author(s):

K. STAMATARIS (Κ. ΣΤΑΜΑΤΑΡΗΣ) ◽

K. DELIGIANNIS (Κ. ΔΕΛΗΓΙΑΝΝΗΣ) ◽

T. LAINAS (Θ. ΛΑΪΝΑΣ) ◽

G. ARSENOS (Γ. ΑΡΣΕΝΟΣ)

Keyword(s):

Survival Rate ◽

Ethylene Glycol ◽

Embryo Transfer ◽

Genetic Material ◽

Embryo Cryopreservation ◽

Embryo Survival ◽

Embryo Recovery ◽

Multiple Ovulation ◽

Large Numbers ◽

Fresh Semen

The objective of the study was to evaluate the use multiple ovulation and embryo transfer techniques in an indigenous Greek dairy breed of sheep. We stimulated selected donor ewes of the Karagouniko breed to produce large numbers of embryos after the induction of multiple ovulations by gonadotropin treatment (superovulatory response). A total of 50 Greek Karagouniko ewes were synchronised into oestrus using progestagen pessaries and superovulated for embryo transfer using ovine FSH. Six days following laparoscopic insemination with fresh semen ewes were flushed surgically and embryos collected. Subsequently, the embryo recovery, along with embryo cryopreservation, embryo survival and quality were assessed. The Karagouniko donor ewes achieved a mean ovulation rate of 11.9 (SE. 0.89). The ova Recovery rate was 80,9% and 87,6% of the ova recovered being fertilised. A total of 327 (77,5%) of the viable embryos were assessed as being of sufficient quality for cryopreservation. The embryos ranged from late morulae to expanded blastocyst and were frozen via a 3-step process in 1.5 M ethylene glycol following repeated washing and trypsination. Cryopreserved embryos were frozen and then transported to Scotland, UK. There, embryos were thawed rapidly and re-hydrated via a 2 step sucrose/ethylene glycol gradient. A total of 92.4% of embryos frozen remained suitable for transfer semi-surgically into synchronized Scottish Blackface ewes. 183 embryos were transferred in total with a 66.1% survival rate. The survival rate of frozen thawed blastocysts(75%) was significantly greater than (P<0.01) that for morulae (48%). It was concluded that MOET could be successfully applied in Greek dairy breeds of sheep as a means for genetic improvement. Frozenembryos could be a successful medium for the transportation of ovine genetic material from and to Greece, however, most likely the choice of embryonic stage for cryopreservation is crucial.

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43 NEW METHOD FOR ONE-STEP WARMING/IN-STRAW CRYOPROTECTANT DILUTION FOR IN VITRO-PRODUCED BOVINE BLASTOCYSTS AFTER VITRIFICATION WITH THE CRYOLOGIC VITRIFICATION METHOD

Reproduction Fertility and Development ◽

10.1071/rdv27n1ab43 ◽

2015 ◽

Vol 27 (1) ◽

pp. 114

Author(s):

J. N. Caamaño ◽

E. Gómez ◽

B. Trigal ◽

M. Muñoz ◽

S. Carrocera ◽

...

Keyword(s):

Embryo Transfer ◽

Survival Rates ◽

Field Conditions ◽

Control Group ◽

Embryo Survival ◽

Grant Support ◽

One Step ◽

The One ◽

New System

Vitrification is considered an alternative to slow-rate freezing to cryopreserve in vitro-produced (IVP) bovine embryos. However, the use of vitrified IVP embryos for embryo transfer under field conditions is difficult because of the requirements of the current thawing protocols. The objective of this study was to develop a simple one-step warming/in-straw cryoprotectant dilution procedure for IVP bovine blastocysts that were vitrified using the cryologic vitrification method. In this study, 109 Day-7 IVP blastocysts were subjected to vitrification using the conventional fibreplugs (groups of 5 embryos were loaded in 3 mL of vitrification medium). Warming was performed in one-step in MS1 (0.25 M sucrose in BV = TCM 199-Hepes + 20% FCS) either using a 4-well plate for 5 min (control group) or in a new system that allowed in-straw cryoprotectant dilution designed to avoid losses of embryos and to maintain the temperature required during this procedure. This new system is composed of an adaptor with a wider opening that is coupled to the French straw and a heated metal chamber to protect and keep the straw at 41°C. Warmed embryos were washed and subsequently cultured in mSOFaaci + 6 gL–1 BSA + 10% FCS for 48 h. Re-expansion (at 2, 24, and 48 h) and hatching rates (at 24 and 48 h) were recorded. Data were analysed by ANOVA and are presented as LSM ± standard error. Embryo survival rates of embryos warmed by the one-step warming/in-straw cryoprotectant dilution procedure did not differ from the control group (see Table 1). These results suggest that the cryologic vitrification method combined with our warming system for in-straw cryoprotectant dilution may be used for direct embryo transfer under field conditions. Table 1.Embryo survival rates of in vitro-produced embryos vitrified by the cryologic vitrification method and warmed by the new one-step warming/in-straw cryoprotectant dilution procedure This study received grant support: INIA-RTA 2011–0090 and FEDER. M. Muñoz was supported by grant MICINN-RYC08-03454, and B. Trigal by a grant from Cajastur. The authors are members of the COST Action FA1201 Epiconcept.

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Controlling reproduction in sheep

BSAP Occasional Publication ◽

10.1017/s0263967x00002020 ◽

1990 ◽

Vol 14 ◽

pp. 23-37 ◽

Cited By ~ 3

Author(s):

W. Haresign

Keyword(s):

Embryo Transfer ◽

Slow Release ◽

Intrauterine Insemination ◽

Surgical Techniques ◽

Point Of View ◽

Multiple Ovulation ◽

Frozen Semen ◽

Recent Developments ◽

Breed Improvement

AbstractIntravaginal progestagen pessaries + pregnant mare's serum gonadotrophin (PMSG) for controlling the oestrous cycle and for inducing out-of-season breeding have been commercially available for many years. However, extremely good mating management is required if acceptable results are to be achieved. More recently the role of the pineal hormone, melatonin, in the regulation of seasonal breeding has been recognized, and this has led to the development of slow-release formulations for use under farm conditions. Early indications are that such preparations can advance the breeding season by about 4 to 6 weeks, with lambing percentages in early (January) lambing flocks comparable with those of traditional (March) lambing flocks.Recent developments in the use of laparoscopy as an aid to intrauterine insemination and multiple ovulation and embryo transfer (MOET) should play a major role in breed improvement. Intrauterine insemination can markedly improve conception rates following the use of frozen semen compared with the conventional cervical technique, as well as eliminating the incidence of fertilization failure in embryo transfer donors. In addition, laparoscopic collection and transfer of embryos permit repeated collections from the same donor ewes and are much more acceptable than surgical techniques from the welfare point of view.

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Marwari goat of Indian desert

Animal Genetic Resources Information ◽

10.1017/s1014233900001346 ◽

2000 ◽

Vol 28 ◽

pp. 35-42

Author(s):

B. Rai ◽

B.U. Khan ◽

P.K. Rout

Keyword(s):

Body Weight ◽

The Body ◽

Field Conditions ◽

Multiple Birth ◽

Production Economics ◽

Nutritional Conditions ◽

Early Maturing ◽

Improvement Programme ◽

Adult Body Weight ◽

Breed Improvement

SummaryMarwari is a desert goat breed of India and is found in the western part of the country. It is well known for its tolerance of hot and cold climates, disease resistance and thriving in very harsh nutritional conditions. It is a hairy black coloured goat. The means of the body length, body weight and ear length were estimated as 54 cm, 83 cm and 20 cm in males and 49 cm, 72 cm and 16 cm in females. Males have larger and stronger horns than females. The average adult body weight in males and females is 46 and 30 kg, respectively. The overall milk yield at 200 days is 98 kg. The kidding percentage in field conditions is 79.3 percent and multiple birth is about 19 percent. The Marwari is an early maturing breed as the average age of puberty is 306 days. The mortality in kid is 3.3 percent and in adults 3.5 percent in field conditions. The marketing and production economics of goats in its home tract have been analysed to ascertain viability of goat enterprise. The breed improvement programme was started in 1990–91 in its home tract involving farmers' flocks.

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