Response to superovulation in Scottish Blackface ewes during seasonal anoestrus

1996 ◽  
Vol 1996 ◽  
pp. 187-187
Author(s):  
L D Dunne ◽  
J J Robinson ◽  
P J Broadbent ◽  
T G McEvoy ◽  
D F Dolman
Keyword(s):  
Embryo Transfer ◽  
Genetic Improvement ◽  
Embryo Production ◽  
Generation Interval ◽  
Multiple Ovulation ◽  
Biological Constraint ◽  
Selection Intensities

A major limitation to the success of genetic improvement programmes using multiple ovulation and embryo transfer is the failure to generate sufficient viable embryos per donor ewe to maintain selection intensities and sustain a low generation interval. Seasonal anoestrus imposes a biological constraint on embryo production in many breeds of sheep. The objective of this study was to investigate the response to superovulation during seasonal anoestrus (April - May) in Scottish Blackface ewes.

Response to superovulation in Scottish Blackface ewes during seasonal anoestrus

1996 ◽  
Vol 1996 ◽  
pp. 187-187
Author(s):  
L D Dunne ◽  
J J Robinson ◽  
P J Broadbent ◽  
T G McEvoy ◽  
D F Dolman
Keyword(s):  
Embryo Transfer ◽  
Genetic Improvement ◽  
Embryo Production ◽  
Generation Interval ◽  
Multiple Ovulation ◽  
Biological Constraint ◽  
Selection Intensities

A major limitation to the success of genetic improvement programmes using multiple ovulation and embryo transfer is the failure to generate sufficient viable embryos per donor ewe to maintain selection intensities and sustain a low generation interval. Seasonal anoestrus imposes a biological constraint on embryo production in many breeds of sheep. The objective of this study was to investigate the response to superovulation during seasonal anoestrus (April - May) in Scottish Blackface ewes.

Increased rates of genetic change in dairy cattle by embryo transfer and splitting

1983 ◽  
Vol 36 (3) ◽  
pp. 341-353 ◽  
Author(s):  
F. W. Nicholas ◽  
C. Smith
Keyword(s):  
Dairy Cattle ◽  
Embryo Transfer ◽  
Genetic Improvement ◽  
Genetic Change ◽  
Progeny Testing ◽  
Generation Interval ◽  
Advantages And Disadvantages ◽  
Multiple Ovulation ◽  
Inbreeding Rate ◽  
Old Females

ABSTRACTPossibilities for increased rates of genetic change in dairy cattle through embryo transfer and embryo splitting are examined, using the multiple ovulation and embryo transfer systems previously proposed. These involve embryo transfer from 1-year-old females (juvenile scheme, generation interval 1·8 years) and from females after 1 lactation (adult scheme, generation interval 3·7 years), with use of males at similar ages. Though selection is less accurate than in conventional progeny testing, the annual rate of genetic improvement can be increased, and even doubled. If the number of transfers is restricted andm the inbreeding rate is limiting, the adult scheme for both sexes is preferred. A scheme with 1 024 transfers per year and 512 females milk-recorded per year will sustain a rate of genetic improvement some 30% above that possible by a conventional national progeny-testing programme. Because of the relatively small number of animals involved, it is argued that greater control over recording, breeding and selection should be possible, leading to a larger proportion of the possible genetic gains being realized in practice. Other advantages, and disadvantages of these systems, and their integration in dairy cattle improvement are discussed.

Comparison of genetic response and inbreeding coefficient when the MOET technique and different proportions of proven and young bull semen were used in dairy herds

2005 ◽  
Vol 2005 ◽  
pp. 129-129
Author(s):  
M. Aminafshar ◽  
M. Moradi Shahrebabak ◽  
M. Sanjabi ◽  
A. Lavvaf
Keyword(s):  
Embryo Transfer ◽  
Genetic Improvement ◽  
Inbreeding Coefficient ◽  
Dairy Herds ◽  
Genetic Response ◽  
Young Bull ◽  
Bull Semen ◽  
Multiple Ovulation ◽  
Breeding Schemes ◽  
Potential Improvement

Breeding schemes with multiple ovulation and embryo transfer opens up a possibility to enhance genetic improvement through intense female selection and short generation intervals. The potential improvement in genetic response may increase when elite cows produce a number of embryos, instead of one calf per year. Also different ratio of proven bull and young bull semen may be used to inseminate cows in the herd. The objective of this project has been to investigate genetic response and coefficient of inbreeding, when elite cows produce number of embryos during a year, instead of reproducing one calf per year. Also genetic response and inbreeding coefficient were estimated when different ratio of proven bull and young bull semen were used to inseminate cows in the herd.

Influence of age of donor ewe on MOET in Texel sheep

1994 ◽  
Vol 1994 ◽  
pp. 86-86
Author(s):  
B.T. Wolf ◽  
M.J.A. Mylne
Keyword(s):  
Embryo Transfer ◽  
Genetic Improvement ◽  
Follicle Stimulating Hormone ◽  
Selection Intensity ◽  
Female Reproduction ◽  
Sheep Breeding ◽  
Multiple Ovulation ◽  
Genetic Benefits ◽  
Chemical Products ◽  
Aged Donor

Smith (1986) identified the theoretical potential of multiple ovulation and embryo transfer (MOET) to increase the rate of genetic improvement within nucleus sheep breeding flocks by upto 100%. The likely genetic benefits of MOET arise from the potential to overcome limits to female reproduction thus allowing increased selection intensity and reduced generation intervals among females. The present study was conducted to evaluate the potential for MOET from 18 month-old maiden ewes (gimmers) in comparison with aged donor ewes.In October 1991, a group of twenty 18-month old ewes and twenty aged ewes (3.5 year-old) were synchronised into oestrus using intravaginal pessaries containing 45 mg Cronolone (Chronogest, Intervet Laboratories Ltd.) inserted for 12 days. Superovulation was achieved using 20 i.u. of ovine follicle stimulating hormone (Ovagen, Immuno-Chemical Products N.Z. Ltd) given in eight equal doses at 12-hourly intervals starting 58 hours before progestagen pessary withdrawal.

Comparison of MOET in Texel ewe lambs and yearling ewes

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.

Superovulation in the ewe: the effects of source of gonadotrophin, season, breed and age

1993 ◽  
Vol 1993 ◽  
pp. 59-59
Author(s):  
K. Fernie ◽  
W.S. Dingwall ◽  
W.A.C. McKelvey ◽  
J. FitzSimons
Keyword(s):  
Treatment Period ◽  
Embryo Transfer ◽  
Genetic Improvement ◽  
Ovulation Rate ◽  
Pituitary Extract ◽  
Multiple Ovulation ◽  
The Mean ◽  
Chemical Products ◽  
Different Sources ◽  
Potential Rate

The potential rate of genetic improvement which can be achieved in sheep through the use of multiple ovulation and embryo transfer (MOET) is limited by the great variation in the response of ewes to superovulation treatments. Factors which have been shown to influence natural ovulation rate in the ewe include season, breed, age and the administration of exogenous gonadotrophins from different sources. The following study was conducted to examine the effects of these factors on the response of ewes to superovulation treatments, with a view to increasing the mean ovulation rate and to concurrently decrease the between-ewe variability.During the course of 4 experiments a total of 170 ewes (Suffolk and Texel) were treated with 45mg progestagen-impregnated intravaginal pessaries (Chronogest: Intervet Laboratories Ltd.) for a period of 12 days. Sixteen ewes had no further treatment and were used as controls. The remaining 154 ewes, were treated with one of two exogenous gonadotropin preparations on days 10, 11, 12 and 13 of the progestagen treatment period (day 0 = pessary insertion). One group (n = 76) was treated with a porcine pituitary extract (pFSH) and the second (n = 78) with a highly purified ovine FSH (Ovagen: Immuno-Chemical Products).

scholarly journals Effects of alfaprostol and luprostiol on the embryo production within MOET technique in Black Bengal goats

1970 ◽  
Vol 2 (2) ◽  
pp. 147-150 ◽  
Author(s):  
MI Faruk ◽  
BZ Fatema ◽  
FY Bari ◽  
MGS Alam
Keyword(s):  
Treatment Group ◽  
Embryo Transfer ◽  
Treated Group ◽  
Embryo Production ◽  
Recovery Method ◽  
Treatment Groups ◽  
Multiple Ovulation ◽  
Significant Difference ◽  
Surgical Recovery ◽  
The Mean

The effects of Alfaprostol and Luprostiol on embryo production within multiple ovulation and embryo transfer (MOET) technique were studied on 16 Black Bengal goats during the period from January 2002 to June 2003. These 16 goats were randomly divided into two equal groups (A & B), each consisting of 8 goats. Each of the 16 goats was flushed in different times within MOET technique to determine the effects of alfaprostol and luprostiol on embryo production. Each group consisting of 8 donors was synchronized with alfaprostol (Gabbrostim®, VETEM, Italy) or luprostiol (Prosolvin®, Intervet International, Netherlands) @ 2 mg and 7.5 mg, equivalent to 1 ml / donor respectively. The donor goats were hand mated following the onset of oestrus, 1-2 times at 6 h interval depending on the duration of oestrus. The embryos were collected at Day 7 of mating using surgical recovery method. The mean number of ovulation in alfaprostol and luprostiol group was 8.50 ± 0.90 and 8.1 ± 0.76, respectively, where in both cases 900 iu PMSG was used for induction. There was no significant (p > 0.05) difference between this two groups on superovulation rate. The mean numbers of recovered, fertilized and transferable embryos were 5.4 ± 0.80 and 5.1 ± 0.61; 3.9 ± 0.52 and 2.6 ± 0.37 and 3.6 ± 1.6 and 2.4 ± 1.0, respectively, in alfaprostol and luprostiol treatment group. Like superovulation, there was no difference between the two treatment groups on recovered, fertilized and transferable embryos. The percentage of recovered, fertilized and transferable embryos were 63 ± 7.7 and 63 ± 3.74, 72 ± 4.55 and 51 ± 7.0 and 93.6 ± 1.6 and 90.48 ± 1.0 in alfaprostol and luprostiol treated groups, respectively. The significant difference was only existed in the percentages of fertilized embryos between the two treatment groups, where alfaprostol treated group had the significantly (p < 0.01) higher percentage of fertilized embryos.Key words: Alfaprostol; luprostiol; effect; embryo transfer; ovulation; Black Bengal goatsdoi: 10.3329/bjvm.v2i2.2558Bangl. J. Vet. Med. (2004). 2 (2): 147-150

Multiple Ovulation and Embryo Transfer in Hill Ewes

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.

The use of embryo transfer in ruminant genetic improvement programmes

1992 ◽  
Vol 1992 ◽  
pp. 6-6
Author(s):  
G Simm
Keyword(s):  
Gene Transfer ◽  
Disease Control ◽  
Embryo Transfer ◽  
Genetic Improvement ◽  
Genetic Material ◽  
Small Ruminants ◽  
Embryo Recovery ◽  
Multiple Ovulation ◽  
Import And Export

Over the course of the last 40 years or so increasingly reliable procedures have been developed for multiple ovulation, embryo recovery and embryo transfer, initially for cattle (see review of Woolliams and Wilmut, 1989) and, more recently, for small ruminants (McKelvey and Robinson, 1986). During this time a number of applications have been proposed or practised. These include uses in (i) within-breed genetic improvement programmes, (ii) the import and export of genetic material (offering potential advantages in economy, animal welfare and disease control), (iii) accelerating breed substitution by multiplication of newly introduced breeds and (iv) conservation of genetic material (by freezing embryos) from valuable individual animals, or from rare or endangered breeds or species. Additionally, there are several new ‘reproductive’ procedures available or being developed for use in animal production (eg. in vitro fertilisation, embryo sexing, cloning, gene transfer) which hinge on the use of embryo transfer. These are discussed in detail by Woolliams and Wilmut (1989) and in the following two papers. The aim of this paper is to examine the first of the applications listed above - the use of multiple ovulation and embryo transfer (MOET) in within-breed genetic improvement programmes.

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