Superovulation in Mares

Squires, E.L.

doi:10.1016/j.cveq.2006.07.005

Cited by 19 publications

(14 citation statements)

References 29 publications

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“…Because there is currently no reliable method to stimulate superovulation and collect more than one or two embryos per oestrous cycle in donor mares, repeated embryo collection is necessary to produce numerous foals (Squires and McCue 2007). In this study, it was demonstrated that in young fertile mares, repeated insemination and embryo collection does not impair embryo recovery rates.…”

Section: Discussionmentioning

confidence: 73%

“…The use of performance mares competing successfully in equestrian sport as embryo donors may contribute to genetic progress in sport horse breeding (Aurich and Aurich 2006). Because the number of embryos that can be collected from a donor mare in one embryo collection is limited (Squires and McCue 2007), repeated collection is necessary if more than one foal should be produced. Horse owners and veterinarians may have concerns about using a young mare repeatedly as embryo donor.…”

Section: Introductionmentioning

confidence: 99%

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Effects of Repeated Embryo Collection on Embryo Recovery Rate in Fertile Mares

Aurich

König

Budik

2011

Reprod Domestic Animals

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In mares, repeated embryo collection in successive oestrous cycles is necessary if a greater number of foals should be produced. We investigated effects of repeated embryo collection in fertile donor mares on embryo recovery rates. In addition, an influence of the individual mare and season on embryo recovery rates was studied. In nine mares, a total of 153 embryo collections were performed during 30 months (17 ± 2.2 embryo collections per mare). The overall embryo recovery rate was 64% and did not differ among mares. Between successive embryo collection procedures, recovery rate varied significantly; however, no increase or decrease in the embryo recovery rate with increasing number of successive embryo collections was seen. In three mares, ovulation ceased from November to February. In the remaining six mares, embryo production was successfully continued throughout winter and no influence of the month on embryo recovery rates was detected.

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Section: Discussionmentioning

confidence: 73%

Section: Introductionmentioning

confidence: 99%

Effects of Repeated Embryo Collection on Embryo Recovery Rate in Fertile Mares

Aurich

König

Budik

2011

Reprod Domestic Animals

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“…We selected the doses and frequencies of the FSH treatments according to previous reports describing treatments of cycling mares with eFSH Ò (McCue et al 2007a) and with Folltropin Ò -V (Fortune and Kimmich 1993;Krekeler et al 2006). However, the doses of the two hormones cannot be compared; whereas the amount of FSH in the To our best knowledge, the bioavailability and potency of eFSH Ò and Folltropin Ò -V in horses have never been critically compared; still, it has been suggested that porcine-FSH does not bind to the equine follicle with the same affinity as equine-FSH (Chopineau et al 1997;Squires and McCue 2007). When compared with porcine gonadotropins, equine gonadotropins incorporate higher carbohydrates and sialic acid content, which may play an important role in their biological activity and may extend their half life (Whitley et al 1981;Ginther 1992;van Dijk and Ward 1992;Rose et al 2000).…”

Section: Discussionmentioning

confidence: 99%

“…Purified porcine-FSH (Folltropin Ò -V, Bioniche Animal Health Inc.) is an affordable commercially available form of FSH which is widely used to induce superovulation in donor cows (Mapletoft et al 2002). In mares, different forms of porcine-FSH have been reported to increase the number of ovulations (Irvine 1981;Squires et al 1986;Fortune and Kimmich 1993) and the rates of embryo recovery in cycling donor mares (Veselinovic et al 1994;Krekeler et al 2006), when compared with non-treated control; however, it was not widely accepted as a superovulatory treatment in the equine industry as the results were inferior to those obtained with gonadotropins of equine-origin (Squires et al 1986;Veselinovic et al 1994;Squires and McCue 2007). Nevertheless, the potential benefits of purified porcine-FSH in transitional mares have never been examined.…”

Section: Introductionmentioning

confidence: 99%

Ovulation, Pregnancy Rate and Early Embryonic Development in Vernal Transitional Mares Treated with Equine- or Porcine-FSH

Raz

Amorim

Stover

et al. 2010

Reproduction in Domestic Animals

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The objective of this study was to compare the efficacy of purified equine- and porcine-FSH treatment regimes in mares in early vernal transition. Mares (n = 22) kept under ambient light were examined ultrasonographically per-rectum, starting January 30th. They were assigned to one of two treatment groups using a sequential alternating treatment design when a follicle >or= 25 mm was detected. In the eFSH group, mares were treated twice daily with equine-FSH, and in the pFSH group mares were treated twice daily with porcine-FSH; treatments were continued until follicle(s) >or= 35 mm, and 24 h later hCG was administered. Oestrous mares were inseminated with fresh semen and examined for pregnancy on days 11-20 post-ovulation. In the eFSH group, 11/11 (100%) mares developed follicle(s) >or= 35 mm, 8/11 (73%) ovulated and 6/8 (75%) conceived. In the pFSH group, 5/11 (45%) developed follicle(s) >or= 35 mm, 4/11 (36%) ovulated and 3/4 (75%) conceived. Treatment with eFSH resulted in a greater ovarian stimulation; higher number of pre-ovulatory-sized follicles, higher number of ovulations and higher number of embryos (p < 0.05). Following ovulation, serum progesterone concentrations were correlated with the number of CLs and supported early embryonic development; maternal recognition of pregnancy occurred in all pregnant mares. We concluded that eFSH can be used to effectively induce follicular growth and ovulation in vernal transitional mares; however, if bred, diagnosis and management of twins' pregnancies would be required prior to day 16 because of the increased risk of multiple embryos per pregnancy. Conversely, the current pFSH treatment regime cannot be recommended.

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“…In horse breeding, ET is well suited to practical use since a long time (Leidl & Braun 1987). The mean recovery rate for embryos is reported to be 64%, and the mean adhesion rate is specified with 70%, resulting in a pregnancy rate of 45% for each flushing (Squires & Mc Cue 2007). While there is no commercially available method to stimulate multiple ovulations in horse breeding today (Squires et al 2003), there are successful efforts to increase the number of ovulated ova in horses (Squires & Mc Cue 2007).…”

Section: Introductionmentioning

confidence: 99%

The potential of embryo transfer in a German horse‐breeding programme

Sitzenstock

Rathke

Ytournel

et al. 2012

J Animal Breeding Genetics

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A reference horse-breeding programme with 13500 foals each year was modelled with ZPLAN+. This new software for the optimization of the structures in breeding programmes is based on ZPLAN. In two scenarios, the implementation of a rigorous selection of mares was implemented. In scenario I, the mare performance test was the point of selection, while in scenario II, further information on 20 competitions in two more years is available. These selected mares were used for embryo transfer (ET), partly in combination with multiple ovulation (MOET). The selection intensity and the number of foals out of (MO)ET were varied in both scenarios. It was expected that 250, 500 and 1000 mares are available for selecting 20, 50, 100 or 200 donor mares each year. The number of foals out of (MO)ET was varied between one and six foals per donor mare and year. Donor mares were used for ET for 4 years. It became clear that with high selection intensities of donor mares and high reproduction rates of them, the yearly genetic gain in a horse-breeding programme could increase over a large range. In scenario II, the additional information on 20 competitions increased the accuracy of the selection index to 0.85. With 200 selected donor mares of 1000 available mares and six foals per year, the genetic gain could almost be doubled compared to the reference scenario. The implementation of ET and a related higher usage of few selected mares entails rising costs and a reduction in the genetic variance. In the most extreme MOET scenario, the effective population size was reduced by 19% relative to the reference scenario. Only if the increase in genetic gain can be converted into higher return for the breeders, the implementation of (MO)ET schemes is a realistic and sensible option for horse-breeding programmes.

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Superovulation in Mares

Cited by 19 publications

References 29 publications

Effects of Repeated Embryo Collection on Embryo Recovery Rate in Fertile Mares

Effects of Repeated Embryo Collection on Embryo Recovery Rate in Fertile Mares

Ovulation, Pregnancy Rate and Early Embryonic Development in Vernal Transitional Mares Treated with Equine- or Porcine-FSH

The potential of embryo transfer in a German horse‐breeding programme

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