Superovulatory Responses to eCG in Llamas (LAMA-GLAMA)

D A Bourke, C E Kyle, T G McEvoy, Pauline Young, Clare Lesley Adam

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

Llamas are copulation-induced single-ovulators, and multiple ovulation and embryo transfer (MOET) methods have not yet been developed for this species. Superovulatory responses to eCG given during an induced (Group A) or simulated (Group B) luteal phase were investigated using ultrasound to observe ovarian follicles and corpora lutea (CLs) and plasma progesterone was used to assess luteal function. Embryos were recovered nonsurgically. Group A (n=19) : donors were given 8 mu g, im GnRH analogue (Day 0) to induce ovulation of a mature follicle, 1000 IU, im eCG (Day 7), and 250 mu g PGF(2 alpha) analogue (Day 9). Group B (n=17): donors were given a subcutaneous progestagen implant (3 mg Norgestomet) at Days 0 to 7) and 1000 IU, im eCG (Day 5). When most (>65%;) of the follicles in both Groups A and B had matured at 5 to 11 d post eCG, the donors were given 8 mu g, im GnRH and mated once (n=26) or twice within a 24-h interval (n=10); embryos were recovered 6 to 9 d post ovulation. More follicles and corpora lutea were induced in Group B than in Group A, but a similar mean number of embryos were recovered (1.3 vs 1.6), and a similar proportion of donors yielded multiple embryos (35 vs 32%). The embryo recovery rate was similar for Groups A and B (39 and 37%), but it was higher (P<0.001) with 2 (72%) rather than 1 (22%) mating, and it was negatively correlated with CL number (P<0.05). Overall, 80% of the llamas had a precocious CL and elevated plasma progesterone concentrations when multiple follicles reached maturity. This was associated with increased subsequent superovulation and embryo recovery (P<0.01). Peak plasma progesterone was positively correlated with the CL number (P<0.05). From these results we conclude that superovulation may be achieved with eCG given during either an induced or a simulated luteal phase, that embryo recovery is improved following 2 matings rather than 1, and that MOET may indeed be feasible for use in the llama.

Original languageEnglish
Pages (from-to)255-268
Number of pages14
JournalTheriogenology
Volume44
Issue number2
Publication statusPublished - 15 Jul 1995

Keywords

  • SUPEROVULATION
  • LLAMAS
  • EMBRYO
  • GNRH
  • PROGESTAGEN
  • PLASMA PROGESTERONE CONCENTRATIONS
  • CATTLE
  • GOATS
  • PMSG
  • FSH
  • superovulation
  • llamas
  • embryo
  • progestagen
  • plasma progesterone concentrations
  • cattle
  • goats

Cite this

Bourke, D. A., Kyle, C. E., McEvoy, T. G., Young, P., & Adam, C. L. (1995). Superovulatory Responses to eCG in Llamas (LAMA-GLAMA). Theriogenology, 44(2), 255-268.

Superovulatory Responses to eCG in Llamas (LAMA-GLAMA). / Bourke, D A ; Kyle, C E ; McEvoy, T G ; Young, Pauline; Adam, Clare Lesley.

In: Theriogenology, Vol. 44, No. 2, 15.07.1995, p. 255-268.

Research output: Contribution to journalArticle

Bourke, DA, Kyle, CE, McEvoy, TG, Young, P & Adam, CL 1995, 'Superovulatory Responses to eCG in Llamas (LAMA-GLAMA)', Theriogenology, vol. 44, no. 2, pp. 255-268.
Bourke DA, Kyle CE, McEvoy TG, Young P, Adam CL. Superovulatory Responses to eCG in Llamas (LAMA-GLAMA). Theriogenology. 1995 Jul 15;44(2):255-268.
Bourke, D A ; Kyle, C E ; McEvoy, T G ; Young, Pauline ; Adam, Clare Lesley. / Superovulatory Responses to eCG in Llamas (LAMA-GLAMA). In: Theriogenology. 1995 ; Vol. 44, No. 2. pp. 255-268.
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abstract = "Llamas are copulation-induced single-ovulators, and multiple ovulation and embryo transfer (MOET) methods have not yet been developed for this species. Superovulatory responses to eCG given during an induced (Group A) or simulated (Group B) luteal phase were investigated using ultrasound to observe ovarian follicles and corpora lutea (CLs) and plasma progesterone was used to assess luteal function. Embryos were recovered nonsurgically. Group A (n=19) : donors were given 8 mu g, im GnRH analogue (Day 0) to induce ovulation of a mature follicle, 1000 IU, im eCG (Day 7), and 250 mu g PGF(2 alpha) analogue (Day 9). Group B (n=17): donors were given a subcutaneous progestagen implant (3 mg Norgestomet) at Days 0 to 7) and 1000 IU, im eCG (Day 5). When most (>65{\%};) of the follicles in both Groups A and B had matured at 5 to 11 d post eCG, the donors were given 8 mu g, im GnRH and mated once (n=26) or twice within a 24-h interval (n=10); embryos were recovered 6 to 9 d post ovulation. More follicles and corpora lutea were induced in Group B than in Group A, but a similar mean number of embryos were recovered (1.3 vs 1.6), and a similar proportion of donors yielded multiple embryos (35 vs 32{\%}). The embryo recovery rate was similar for Groups A and B (39 and 37{\%}), but it was higher (P<0.001) with 2 (72{\%}) rather than 1 (22{\%}) mating, and it was negatively correlated with CL number (P<0.05). Overall, 80{\%} of the llamas had a precocious CL and elevated plasma progesterone concentrations when multiple follicles reached maturity. This was associated with increased subsequent superovulation and embryo recovery (P<0.01). Peak plasma progesterone was positively correlated with the CL number (P<0.05). From these results we conclude that superovulation may be achieved with eCG given during either an induced or a simulated luteal phase, that embryo recovery is improved following 2 matings rather than 1, and that MOET may indeed be feasible for use in the llama.",
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AU - Bourke, D A

AU - Kyle, C E

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AU - Young, Pauline

AU - Adam, Clare Lesley

PY - 1995/7/15

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N2 - Llamas are copulation-induced single-ovulators, and multiple ovulation and embryo transfer (MOET) methods have not yet been developed for this species. Superovulatory responses to eCG given during an induced (Group A) or simulated (Group B) luteal phase were investigated using ultrasound to observe ovarian follicles and corpora lutea (CLs) and plasma progesterone was used to assess luteal function. Embryos were recovered nonsurgically. Group A (n=19) : donors were given 8 mu g, im GnRH analogue (Day 0) to induce ovulation of a mature follicle, 1000 IU, im eCG (Day 7), and 250 mu g PGF(2 alpha) analogue (Day 9). Group B (n=17): donors were given a subcutaneous progestagen implant (3 mg Norgestomet) at Days 0 to 7) and 1000 IU, im eCG (Day 5). When most (>65%;) of the follicles in both Groups A and B had matured at 5 to 11 d post eCG, the donors were given 8 mu g, im GnRH and mated once (n=26) or twice within a 24-h interval (n=10); embryos were recovered 6 to 9 d post ovulation. More follicles and corpora lutea were induced in Group B than in Group A, but a similar mean number of embryos were recovered (1.3 vs 1.6), and a similar proportion of donors yielded multiple embryos (35 vs 32%). The embryo recovery rate was similar for Groups A and B (39 and 37%), but it was higher (P<0.001) with 2 (72%) rather than 1 (22%) mating, and it was negatively correlated with CL number (P<0.05). Overall, 80% of the llamas had a precocious CL and elevated plasma progesterone concentrations when multiple follicles reached maturity. This was associated with increased subsequent superovulation and embryo recovery (P<0.01). Peak plasma progesterone was positively correlated with the CL number (P<0.05). From these results we conclude that superovulation may be achieved with eCG given during either an induced or a simulated luteal phase, that embryo recovery is improved following 2 matings rather than 1, and that MOET may indeed be feasible for use in the llama.

AB - Llamas are copulation-induced single-ovulators, and multiple ovulation and embryo transfer (MOET) methods have not yet been developed for this species. Superovulatory responses to eCG given during an induced (Group A) or simulated (Group B) luteal phase were investigated using ultrasound to observe ovarian follicles and corpora lutea (CLs) and plasma progesterone was used to assess luteal function. Embryos were recovered nonsurgically. Group A (n=19) : donors were given 8 mu g, im GnRH analogue (Day 0) to induce ovulation of a mature follicle, 1000 IU, im eCG (Day 7), and 250 mu g PGF(2 alpha) analogue (Day 9). Group B (n=17): donors were given a subcutaneous progestagen implant (3 mg Norgestomet) at Days 0 to 7) and 1000 IU, im eCG (Day 5). When most (>65%;) of the follicles in both Groups A and B had matured at 5 to 11 d post eCG, the donors were given 8 mu g, im GnRH and mated once (n=26) or twice within a 24-h interval (n=10); embryos were recovered 6 to 9 d post ovulation. More follicles and corpora lutea were induced in Group B than in Group A, but a similar mean number of embryos were recovered (1.3 vs 1.6), and a similar proportion of donors yielded multiple embryos (35 vs 32%). The embryo recovery rate was similar for Groups A and B (39 and 37%), but it was higher (P<0.001) with 2 (72%) rather than 1 (22%) mating, and it was negatively correlated with CL number (P<0.05). Overall, 80% of the llamas had a precocious CL and elevated plasma progesterone concentrations when multiple follicles reached maturity. This was associated with increased subsequent superovulation and embryo recovery (P<0.01). Peak plasma progesterone was positively correlated with the CL number (P<0.05). From these results we conclude that superovulation may be achieved with eCG given during either an induced or a simulated luteal phase, that embryo recovery is improved following 2 matings rather than 1, and that MOET may indeed be feasible for use in the llama.

KW - SUPEROVULATION

KW - LLAMAS

KW - EMBRYO

KW - GNRH

KW - PROGESTAGEN

KW - PLASMA PROGESTERONE CONCENTRATIONS

KW - CATTLE

KW - GOATS

KW - PMSG

KW - FSH

KW - superovulation

KW - llamas

KW - embryo

KW - progestagen

KW - plasma progesterone concentrations

KW - cattle

KW - goats

M3 - Article

VL - 44

SP - 255

EP - 268

JO - Theriogenology

JF - Theriogenology

SN - 0093-691X

IS - 2

ER -