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Robin C Anderson - One of the best experts on this subject based on the ideXlab platform.

  • ovarian reaction and estrus manifestation in delayed puberty Gilts after treatment with equine chorionic gonadotropin
    Reproductive Biology and Endocrinology, 2012
    Co-Authors: Ivan Stancic, Darko Bosnjak, Ivan Radovic, Blagoje Stancic, R B Harvey, Robin C Anderson
    Abstract:

    Background: Prolonged pre-insemination anestrus (i.e. delayed puberty) is a major contributing factor for culling up to 30% of the replacement Gilts at large breeding farm units in Vojvodina. It is imperative to determine if these Gilts are acyclic (prepubertal) or cyclic, but just fail to exhibit behavioural estrus. Recent investigations demonstrate that treatment with equine chorionic gonadotropin (eCG) can increase the diestrous phase duration in sexually mature Gilts. Based on these finding, the aim of the present studies was to determine the reproductive status of delayed puberty Gilts following injection with eCG. Methods: Two experiments were conducted on a swine breeding farm in Vojvodina. In Exp. 1, 20 prepubertal (acyclic) Gilts, and 120 sexually mature (cyclic) Gilts were injected with a single injection of 400 IU eCG+200 IU human chorionic gonadotropin (hCG) or with 1000 IU eCG (cyclic Gilts), at d5, d11 or d17 after spontaneous estrus detection, to determine their ovarian reaction and induced estrus manifestation. In Exp. 2, sixty delayed puberty Gilts (estrus not detected until 8 month of age, av. 258 days) were culled from breeding herd and slaughtered to determine their reproductive status based on ovarian anatomical features. The second group of Gilts (n=60) was treated with a single 1000 IU eCG injection to determine their reproductive status, based on the interval between eCG injection to estrus detection and duration. The data were analyzed by descriptive statistics, t-test, analysis of variance and Duncan’s test in the software package Statistics 10 th . Results: Ovulations were induced in 90% of acyclic (sexually immature) and, on average, 93.3% of cyclic (sexually mature) Gilts after the eCG injection. On average, 4 days after the eCG injection, estrus was detected in 85% of the treated acyclic (sexually immature) Gilts and in 95% (19/20) of the cyclic (sexually mature) Gilts, treated with eCG on day 17 after spontaneous estrus detection. The interval from eCG to induced estrus detection was prolonged (av. 25 days) in 95% (19/20) of the sexually mature Gilts treated with eCG on day 5 and in 90% (18/20) of Gilts treated on day 11 after spontaneous estrus detection (Exp. 1). Forty anestrous Gilts reached cyclic pubertal ovarian activity. Estrus manifestation was detected in 56 Gilts (93.3% of the total 60 treated prolonged anestrous Gilts, av. 259 days of age), after a single 1000 IU eCG injection. Thirty-four Gilts (60.7% of the total Gilts in estrus) with prolonged eCG to estrus interval (av. 24.7 days) were considered spontaneously cyclic (sexually mature), but behaviourally anestrous before treatment. The remaining 22 (39.3% of the total Gilts in estrus) were considered truly sexually immature (acyclic) before the treatment or were eCG injected in the late luteal or proestrous phase of spontaneous estrous cycle (Exp. 2). (Continued on next page)

  • ovarian reaction and estrus manifestation in delayed puberty Gilts after treatment with equine chorionic gonadotropin
    Reproductive Biology and Endocrinology, 2012
    Co-Authors: Ivan Stancic, Darko Bosnjak, Ivan Radovic, Blagoje Stancic, R B Harvey, Robin C Anderson
    Abstract:

    Background: Prolonged pre-insemination anestrus (i.e. delayed puberty) is a major contributing factor for culling up to 30% of the replacement Gilts at large breeding farm units in Vojvodina. It is imperative to determine if these Gilts are acyclic (prepubertal) or cyclic, but just fail to exhibit behavioural estrus. Recent investigations demonstrate that treatment with equine chorionic gonadotropin (eCG) can increase the diestrous phase duration in sexually mature Gilts. Based on these finding, the aim of the present studies was to determine the reproductive status of delayed puberty Gilts following injection with eCG. Methods: Two experiments were conducted on a swine breeding farm in Vojvodina. In Exp. 1, 20 prepubertal (acyclic) Gilts, and 120 sexually mature (cyclic) Gilts were injected with a single injection of 400 IU eCG+200 IU human chorionic gonadotropin (hCG) or with 1000 IU eCG (cyclic Gilts), at d5, d11 or d17 after spontaneous estrus detection, to determine their ovarian reaction and induced estrus manifestation. In Exp. 2, sixty delayed puberty Gilts (estrus not detected until 8 month of age, av. 258 days) were culled from breeding herd and slaughtered to determine their reproductive status based on ovarian anatomical features. The second group of Gilts (n=60) was treated with a single 1000 IU eCG injection to determine their reproductive status, based on the interval between eCG injection to estrus detection and duration. The data were analyzed by descriptive statistics, t-test, analysis of variance and Duncan’s test in the software package Statistics 10 th . Results: Ovulations were induced in 90% of acyclic (sexually immature) and, on average, 93.3% of cyclic (sexually mature) Gilts after the eCG injection. On average, 4 days after the eCG injection, estrus was detected in 85% of the treated acyclic (sexually immature) Gilts and in 95% (19/20) of the cyclic (sexually mature) Gilts, treated with eCG on day 17 after spontaneous estrus detection. The interval from eCG to induced estrus detection was prolonged (av. 25 days) in 95% (19/20) of the sexually mature Gilts treated with eCG on day 5 and in 90% (18/20) of Gilts treated on day 11 after spontaneous estrus detection (Exp. 1). Forty anestrous Gilts reached cyclic pubertal ovarian activity. Estrus manifestation was detected in 56 Gilts (93.3% of the total 60 treated prolonged anestrous Gilts, av. 259 days of age), after a single 1000 IU eCG injection. Thirty-four Gilts (60.7% of the total Gilts in estrus) with prolonged eCG to estrus interval (av. 24.7 days) were considered spontaneously cyclic (sexually mature), but behaviourally anestrous before treatment. The remaining 22 (39.3% of the total Gilts in estrus) were considered truly sexually immature (acyclic) before the treatment or were eCG injected in the late luteal or proestrous phase of spontaneous estrous cycle (Exp. 2). (Continued on next page)

  • ovarian activity and uterus organometry in delayed puberty Gilts
    Theriogenology, 2011
    Co-Authors: Ivan Stancic, Blagoje Stancic, R B Harvey, Robin C Anderson, Aleksandar Bozic, Dragan Gvozdic
    Abstract:

    About 30% of the total number of Gilts selected for reproduction at the large breeding farm units in Vojvodina (Republic of Serbia) are culled due to prolonged pre-insemination anoestrus (estrus not detected until 8 mo of age). The aim of this study was to provide the answer to the following question: do the culling Gilts reach cyclic ovarian activity at all? One hundred seventy five culled Gilts in which external estrus manifestations were not detected by 8 mo of age were sacrificed and their reproductive organs were examined for determination of sexual maturity (ovaries exhibiting pre-ovulatory follicles 8 to 11 mm in diameter, corpora hemorrhagica, corpora lutea and corpora albicantia). Uterine weights and horn length were also determined. Functional ovaries were observed in 107 (61.1%) examined Gilts, with 62 animals having one and 45 having two puberty ovarian cycles (57.9% and 42.1%, respectively). Pathomorphological changes which could result in prolonged pre-insemination anoestrus were not observed on the reproductive organs of sexually mature Gilts. Our results indicate that most of the culling Gilts have reached cyclic ovarian activity. The main reason for culling due to the absence of external estrus manifestations in sexually mature Gilts could be inadequate estrus detection technology.

Ivan Stancic - One of the best experts on this subject based on the ideXlab platform.

  • ovarian reaction and estrus manifestation in delayed puberty Gilts after treatment with equine chorionic gonadotropin
    Reproductive Biology and Endocrinology, 2012
    Co-Authors: Ivan Stancic, Darko Bosnjak, Ivan Radovic, Blagoje Stancic, R B Harvey, Robin C Anderson
    Abstract:

    Background: Prolonged pre-insemination anestrus (i.e. delayed puberty) is a major contributing factor for culling up to 30% of the replacement Gilts at large breeding farm units in Vojvodina. It is imperative to determine if these Gilts are acyclic (prepubertal) or cyclic, but just fail to exhibit behavioural estrus. Recent investigations demonstrate that treatment with equine chorionic gonadotropin (eCG) can increase the diestrous phase duration in sexually mature Gilts. Based on these finding, the aim of the present studies was to determine the reproductive status of delayed puberty Gilts following injection with eCG. Methods: Two experiments were conducted on a swine breeding farm in Vojvodina. In Exp. 1, 20 prepubertal (acyclic) Gilts, and 120 sexually mature (cyclic) Gilts were injected with a single injection of 400 IU eCG+200 IU human chorionic gonadotropin (hCG) or with 1000 IU eCG (cyclic Gilts), at d5, d11 or d17 after spontaneous estrus detection, to determine their ovarian reaction and induced estrus manifestation. In Exp. 2, sixty delayed puberty Gilts (estrus not detected until 8 month of age, av. 258 days) were culled from breeding herd and slaughtered to determine their reproductive status based on ovarian anatomical features. The second group of Gilts (n=60) was treated with a single 1000 IU eCG injection to determine their reproductive status, based on the interval between eCG injection to estrus detection and duration. The data were analyzed by descriptive statistics, t-test, analysis of variance and Duncan’s test in the software package Statistics 10 th . Results: Ovulations were induced in 90% of acyclic (sexually immature) and, on average, 93.3% of cyclic (sexually mature) Gilts after the eCG injection. On average, 4 days after the eCG injection, estrus was detected in 85% of the treated acyclic (sexually immature) Gilts and in 95% (19/20) of the cyclic (sexually mature) Gilts, treated with eCG on day 17 after spontaneous estrus detection. The interval from eCG to induced estrus detection was prolonged (av. 25 days) in 95% (19/20) of the sexually mature Gilts treated with eCG on day 5 and in 90% (18/20) of Gilts treated on day 11 after spontaneous estrus detection (Exp. 1). Forty anestrous Gilts reached cyclic pubertal ovarian activity. Estrus manifestation was detected in 56 Gilts (93.3% of the total 60 treated prolonged anestrous Gilts, av. 259 days of age), after a single 1000 IU eCG injection. Thirty-four Gilts (60.7% of the total Gilts in estrus) with prolonged eCG to estrus interval (av. 24.7 days) were considered spontaneously cyclic (sexually mature), but behaviourally anestrous before treatment. The remaining 22 (39.3% of the total Gilts in estrus) were considered truly sexually immature (acyclic) before the treatment or were eCG injected in the late luteal or proestrous phase of spontaneous estrous cycle (Exp. 2). (Continued on next page)

  • ovarian reaction and estrus manifestation in delayed puberty Gilts after treatment with equine chorionic gonadotropin
    Reproductive Biology and Endocrinology, 2012
    Co-Authors: Ivan Stancic, Darko Bosnjak, Ivan Radovic, Blagoje Stancic, R B Harvey, Robin C Anderson
    Abstract:

    Background: Prolonged pre-insemination anestrus (i.e. delayed puberty) is a major contributing factor for culling up to 30% of the replacement Gilts at large breeding farm units in Vojvodina. It is imperative to determine if these Gilts are acyclic (prepubertal) or cyclic, but just fail to exhibit behavioural estrus. Recent investigations demonstrate that treatment with equine chorionic gonadotropin (eCG) can increase the diestrous phase duration in sexually mature Gilts. Based on these finding, the aim of the present studies was to determine the reproductive status of delayed puberty Gilts following injection with eCG. Methods: Two experiments were conducted on a swine breeding farm in Vojvodina. In Exp. 1, 20 prepubertal (acyclic) Gilts, and 120 sexually mature (cyclic) Gilts were injected with a single injection of 400 IU eCG+200 IU human chorionic gonadotropin (hCG) or with 1000 IU eCG (cyclic Gilts), at d5, d11 or d17 after spontaneous estrus detection, to determine their ovarian reaction and induced estrus manifestation. In Exp. 2, sixty delayed puberty Gilts (estrus not detected until 8 month of age, av. 258 days) were culled from breeding herd and slaughtered to determine their reproductive status based on ovarian anatomical features. The second group of Gilts (n=60) was treated with a single 1000 IU eCG injection to determine their reproductive status, based on the interval between eCG injection to estrus detection and duration. The data were analyzed by descriptive statistics, t-test, analysis of variance and Duncan’s test in the software package Statistics 10 th . Results: Ovulations were induced in 90% of acyclic (sexually immature) and, on average, 93.3% of cyclic (sexually mature) Gilts after the eCG injection. On average, 4 days after the eCG injection, estrus was detected in 85% of the treated acyclic (sexually immature) Gilts and in 95% (19/20) of the cyclic (sexually mature) Gilts, treated with eCG on day 17 after spontaneous estrus detection. The interval from eCG to induced estrus detection was prolonged (av. 25 days) in 95% (19/20) of the sexually mature Gilts treated with eCG on day 5 and in 90% (18/20) of Gilts treated on day 11 after spontaneous estrus detection (Exp. 1). Forty anestrous Gilts reached cyclic pubertal ovarian activity. Estrus manifestation was detected in 56 Gilts (93.3% of the total 60 treated prolonged anestrous Gilts, av. 259 days of age), after a single 1000 IU eCG injection. Thirty-four Gilts (60.7% of the total Gilts in estrus) with prolonged eCG to estrus interval (av. 24.7 days) were considered spontaneously cyclic (sexually mature), but behaviourally anestrous before treatment. The remaining 22 (39.3% of the total Gilts in estrus) were considered truly sexually immature (acyclic) before the treatment or were eCG injected in the late luteal or proestrous phase of spontaneous estrous cycle (Exp. 2). (Continued on next page)

  • ovarian activity and uterus organometry in delayed puberty Gilts
    Theriogenology, 2011
    Co-Authors: Ivan Stancic, Blagoje Stancic, R B Harvey, Robin C Anderson, Aleksandar Bozic, Dragan Gvozdic
    Abstract:

    About 30% of the total number of Gilts selected for reproduction at the large breeding farm units in Vojvodina (Republic of Serbia) are culled due to prolonged pre-insemination anoestrus (estrus not detected until 8 mo of age). The aim of this study was to provide the answer to the following question: do the culling Gilts reach cyclic ovarian activity at all? One hundred seventy five culled Gilts in which external estrus manifestations were not detected by 8 mo of age were sacrificed and their reproductive organs were examined for determination of sexual maturity (ovaries exhibiting pre-ovulatory follicles 8 to 11 mm in diameter, corpora hemorrhagica, corpora lutea and corpora albicantia). Uterine weights and horn length were also determined. Functional ovaries were observed in 107 (61.1%) examined Gilts, with 62 animals having one and 45 having two puberty ovarian cycles (57.9% and 42.1%, respectively). Pathomorphological changes which could result in prolonged pre-insemination anoestrus were not observed on the reproductive organs of sexually mature Gilts. Our results indicate that most of the culling Gilts have reached cyclic ovarian activity. The main reason for culling due to the absence of external estrus manifestations in sexually mature Gilts could be inadequate estrus detection technology.

R B Harvey - One of the best experts on this subject based on the ideXlab platform.

  • ovarian reaction and estrus manifestation in delayed puberty Gilts after treatment with equine chorionic gonadotropin
    Reproductive Biology and Endocrinology, 2012
    Co-Authors: Ivan Stancic, Darko Bosnjak, Ivan Radovic, Blagoje Stancic, R B Harvey, Robin C Anderson
    Abstract:

    Background: Prolonged pre-insemination anestrus (i.e. delayed puberty) is a major contributing factor for culling up to 30% of the replacement Gilts at large breeding farm units in Vojvodina. It is imperative to determine if these Gilts are acyclic (prepubertal) or cyclic, but just fail to exhibit behavioural estrus. Recent investigations demonstrate that treatment with equine chorionic gonadotropin (eCG) can increase the diestrous phase duration in sexually mature Gilts. Based on these finding, the aim of the present studies was to determine the reproductive status of delayed puberty Gilts following injection with eCG. Methods: Two experiments were conducted on a swine breeding farm in Vojvodina. In Exp. 1, 20 prepubertal (acyclic) Gilts, and 120 sexually mature (cyclic) Gilts were injected with a single injection of 400 IU eCG+200 IU human chorionic gonadotropin (hCG) or with 1000 IU eCG (cyclic Gilts), at d5, d11 or d17 after spontaneous estrus detection, to determine their ovarian reaction and induced estrus manifestation. In Exp. 2, sixty delayed puberty Gilts (estrus not detected until 8 month of age, av. 258 days) were culled from breeding herd and slaughtered to determine their reproductive status based on ovarian anatomical features. The second group of Gilts (n=60) was treated with a single 1000 IU eCG injection to determine their reproductive status, based on the interval between eCG injection to estrus detection and duration. The data were analyzed by descriptive statistics, t-test, analysis of variance and Duncan’s test in the software package Statistics 10 th . Results: Ovulations were induced in 90% of acyclic (sexually immature) and, on average, 93.3% of cyclic (sexually mature) Gilts after the eCG injection. On average, 4 days after the eCG injection, estrus was detected in 85% of the treated acyclic (sexually immature) Gilts and in 95% (19/20) of the cyclic (sexually mature) Gilts, treated with eCG on day 17 after spontaneous estrus detection. The interval from eCG to induced estrus detection was prolonged (av. 25 days) in 95% (19/20) of the sexually mature Gilts treated with eCG on day 5 and in 90% (18/20) of Gilts treated on day 11 after spontaneous estrus detection (Exp. 1). Forty anestrous Gilts reached cyclic pubertal ovarian activity. Estrus manifestation was detected in 56 Gilts (93.3% of the total 60 treated prolonged anestrous Gilts, av. 259 days of age), after a single 1000 IU eCG injection. Thirty-four Gilts (60.7% of the total Gilts in estrus) with prolonged eCG to estrus interval (av. 24.7 days) were considered spontaneously cyclic (sexually mature), but behaviourally anestrous before treatment. The remaining 22 (39.3% of the total Gilts in estrus) were considered truly sexually immature (acyclic) before the treatment or were eCG injected in the late luteal or proestrous phase of spontaneous estrous cycle (Exp. 2). (Continued on next page)

  • ovarian reaction and estrus manifestation in delayed puberty Gilts after treatment with equine chorionic gonadotropin
    Reproductive Biology and Endocrinology, 2012
    Co-Authors: Ivan Stancic, Darko Bosnjak, Ivan Radovic, Blagoje Stancic, R B Harvey, Robin C Anderson
    Abstract:

    Background: Prolonged pre-insemination anestrus (i.e. delayed puberty) is a major contributing factor for culling up to 30% of the replacement Gilts at large breeding farm units in Vojvodina. It is imperative to determine if these Gilts are acyclic (prepubertal) or cyclic, but just fail to exhibit behavioural estrus. Recent investigations demonstrate that treatment with equine chorionic gonadotropin (eCG) can increase the diestrous phase duration in sexually mature Gilts. Based on these finding, the aim of the present studies was to determine the reproductive status of delayed puberty Gilts following injection with eCG. Methods: Two experiments were conducted on a swine breeding farm in Vojvodina. In Exp. 1, 20 prepubertal (acyclic) Gilts, and 120 sexually mature (cyclic) Gilts were injected with a single injection of 400 IU eCG+200 IU human chorionic gonadotropin (hCG) or with 1000 IU eCG (cyclic Gilts), at d5, d11 or d17 after spontaneous estrus detection, to determine their ovarian reaction and induced estrus manifestation. In Exp. 2, sixty delayed puberty Gilts (estrus not detected until 8 month of age, av. 258 days) were culled from breeding herd and slaughtered to determine their reproductive status based on ovarian anatomical features. The second group of Gilts (n=60) was treated with a single 1000 IU eCG injection to determine their reproductive status, based on the interval between eCG injection to estrus detection and duration. The data were analyzed by descriptive statistics, t-test, analysis of variance and Duncan’s test in the software package Statistics 10 th . Results: Ovulations were induced in 90% of acyclic (sexually immature) and, on average, 93.3% of cyclic (sexually mature) Gilts after the eCG injection. On average, 4 days after the eCG injection, estrus was detected in 85% of the treated acyclic (sexually immature) Gilts and in 95% (19/20) of the cyclic (sexually mature) Gilts, treated with eCG on day 17 after spontaneous estrus detection. The interval from eCG to induced estrus detection was prolonged (av. 25 days) in 95% (19/20) of the sexually mature Gilts treated with eCG on day 5 and in 90% (18/20) of Gilts treated on day 11 after spontaneous estrus detection (Exp. 1). Forty anestrous Gilts reached cyclic pubertal ovarian activity. Estrus manifestation was detected in 56 Gilts (93.3% of the total 60 treated prolonged anestrous Gilts, av. 259 days of age), after a single 1000 IU eCG injection. Thirty-four Gilts (60.7% of the total Gilts in estrus) with prolonged eCG to estrus interval (av. 24.7 days) were considered spontaneously cyclic (sexually mature), but behaviourally anestrous before treatment. The remaining 22 (39.3% of the total Gilts in estrus) were considered truly sexually immature (acyclic) before the treatment or were eCG injected in the late luteal or proestrous phase of spontaneous estrous cycle (Exp. 2). (Continued on next page)

  • ovarian activity and uterus organometry in delayed puberty Gilts
    Theriogenology, 2011
    Co-Authors: Ivan Stancic, Blagoje Stancic, R B Harvey, Robin C Anderson, Aleksandar Bozic, Dragan Gvozdic
    Abstract:

    About 30% of the total number of Gilts selected for reproduction at the large breeding farm units in Vojvodina (Republic of Serbia) are culled due to prolonged pre-insemination anoestrus (estrus not detected until 8 mo of age). The aim of this study was to provide the answer to the following question: do the culling Gilts reach cyclic ovarian activity at all? One hundred seventy five culled Gilts in which external estrus manifestations were not detected by 8 mo of age were sacrificed and their reproductive organs were examined for determination of sexual maturity (ovaries exhibiting pre-ovulatory follicles 8 to 11 mm in diameter, corpora hemorrhagica, corpora lutea and corpora albicantia). Uterine weights and horn length were also determined. Functional ovaries were observed in 107 (61.1%) examined Gilts, with 62 animals having one and 45 having two puberty ovarian cycles (57.9% and 42.1%, respectively). Pathomorphological changes which could result in prolonged pre-insemination anoestrus were not observed on the reproductive organs of sexually mature Gilts. Our results indicate that most of the culling Gilts have reached cyclic ovarian activity. The main reason for culling due to the absence of external estrus manifestations in sexually mature Gilts could be inadequate estrus detection technology.

Blagoje Stancic - One of the best experts on this subject based on the ideXlab platform.

  • ovarian reaction and estrus manifestation in delayed puberty Gilts after treatment with equine chorionic gonadotropin
    Reproductive Biology and Endocrinology, 2012
    Co-Authors: Ivan Stancic, Darko Bosnjak, Ivan Radovic, Blagoje Stancic, R B Harvey, Robin C Anderson
    Abstract:

    Background: Prolonged pre-insemination anestrus (i.e. delayed puberty) is a major contributing factor for culling up to 30% of the replacement Gilts at large breeding farm units in Vojvodina. It is imperative to determine if these Gilts are acyclic (prepubertal) or cyclic, but just fail to exhibit behavioural estrus. Recent investigations demonstrate that treatment with equine chorionic gonadotropin (eCG) can increase the diestrous phase duration in sexually mature Gilts. Based on these finding, the aim of the present studies was to determine the reproductive status of delayed puberty Gilts following injection with eCG. Methods: Two experiments were conducted on a swine breeding farm in Vojvodina. In Exp. 1, 20 prepubertal (acyclic) Gilts, and 120 sexually mature (cyclic) Gilts were injected with a single injection of 400 IU eCG+200 IU human chorionic gonadotropin (hCG) or with 1000 IU eCG (cyclic Gilts), at d5, d11 or d17 after spontaneous estrus detection, to determine their ovarian reaction and induced estrus manifestation. In Exp. 2, sixty delayed puberty Gilts (estrus not detected until 8 month of age, av. 258 days) were culled from breeding herd and slaughtered to determine their reproductive status based on ovarian anatomical features. The second group of Gilts (n=60) was treated with a single 1000 IU eCG injection to determine their reproductive status, based on the interval between eCG injection to estrus detection and duration. The data were analyzed by descriptive statistics, t-test, analysis of variance and Duncan’s test in the software package Statistics 10 th . Results: Ovulations were induced in 90% of acyclic (sexually immature) and, on average, 93.3% of cyclic (sexually mature) Gilts after the eCG injection. On average, 4 days after the eCG injection, estrus was detected in 85% of the treated acyclic (sexually immature) Gilts and in 95% (19/20) of the cyclic (sexually mature) Gilts, treated with eCG on day 17 after spontaneous estrus detection. The interval from eCG to induced estrus detection was prolonged (av. 25 days) in 95% (19/20) of the sexually mature Gilts treated with eCG on day 5 and in 90% (18/20) of Gilts treated on day 11 after spontaneous estrus detection (Exp. 1). Forty anestrous Gilts reached cyclic pubertal ovarian activity. Estrus manifestation was detected in 56 Gilts (93.3% of the total 60 treated prolonged anestrous Gilts, av. 259 days of age), after a single 1000 IU eCG injection. Thirty-four Gilts (60.7% of the total Gilts in estrus) with prolonged eCG to estrus interval (av. 24.7 days) were considered spontaneously cyclic (sexually mature), but behaviourally anestrous before treatment. The remaining 22 (39.3% of the total Gilts in estrus) were considered truly sexually immature (acyclic) before the treatment or were eCG injected in the late luteal or proestrous phase of spontaneous estrous cycle (Exp. 2). (Continued on next page)

  • ovarian reaction and estrus manifestation in delayed puberty Gilts after treatment with equine chorionic gonadotropin
    Reproductive Biology and Endocrinology, 2012
    Co-Authors: Ivan Stancic, Darko Bosnjak, Ivan Radovic, Blagoje Stancic, R B Harvey, Robin C Anderson
    Abstract:

    Background: Prolonged pre-insemination anestrus (i.e. delayed puberty) is a major contributing factor for culling up to 30% of the replacement Gilts at large breeding farm units in Vojvodina. It is imperative to determine if these Gilts are acyclic (prepubertal) or cyclic, but just fail to exhibit behavioural estrus. Recent investigations demonstrate that treatment with equine chorionic gonadotropin (eCG) can increase the diestrous phase duration in sexually mature Gilts. Based on these finding, the aim of the present studies was to determine the reproductive status of delayed puberty Gilts following injection with eCG. Methods: Two experiments were conducted on a swine breeding farm in Vojvodina. In Exp. 1, 20 prepubertal (acyclic) Gilts, and 120 sexually mature (cyclic) Gilts were injected with a single injection of 400 IU eCG+200 IU human chorionic gonadotropin (hCG) or with 1000 IU eCG (cyclic Gilts), at d5, d11 or d17 after spontaneous estrus detection, to determine their ovarian reaction and induced estrus manifestation. In Exp. 2, sixty delayed puberty Gilts (estrus not detected until 8 month of age, av. 258 days) were culled from breeding herd and slaughtered to determine their reproductive status based on ovarian anatomical features. The second group of Gilts (n=60) was treated with a single 1000 IU eCG injection to determine their reproductive status, based on the interval between eCG injection to estrus detection and duration. The data were analyzed by descriptive statistics, t-test, analysis of variance and Duncan’s test in the software package Statistics 10 th . Results: Ovulations were induced in 90% of acyclic (sexually immature) and, on average, 93.3% of cyclic (sexually mature) Gilts after the eCG injection. On average, 4 days after the eCG injection, estrus was detected in 85% of the treated acyclic (sexually immature) Gilts and in 95% (19/20) of the cyclic (sexually mature) Gilts, treated with eCG on day 17 after spontaneous estrus detection. The interval from eCG to induced estrus detection was prolonged (av. 25 days) in 95% (19/20) of the sexually mature Gilts treated with eCG on day 5 and in 90% (18/20) of Gilts treated on day 11 after spontaneous estrus detection (Exp. 1). Forty anestrous Gilts reached cyclic pubertal ovarian activity. Estrus manifestation was detected in 56 Gilts (93.3% of the total 60 treated prolonged anestrous Gilts, av. 259 days of age), after a single 1000 IU eCG injection. Thirty-four Gilts (60.7% of the total Gilts in estrus) with prolonged eCG to estrus interval (av. 24.7 days) were considered spontaneously cyclic (sexually mature), but behaviourally anestrous before treatment. The remaining 22 (39.3% of the total Gilts in estrus) were considered truly sexually immature (acyclic) before the treatment or were eCG injected in the late luteal or proestrous phase of spontaneous estrous cycle (Exp. 2). (Continued on next page)

  • ovarian activity and uterus organometry in delayed puberty Gilts
    Theriogenology, 2011
    Co-Authors: Ivan Stancic, Blagoje Stancic, R B Harvey, Robin C Anderson, Aleksandar Bozic, Dragan Gvozdic
    Abstract:

    About 30% of the total number of Gilts selected for reproduction at the large breeding farm units in Vojvodina (Republic of Serbia) are culled due to prolonged pre-insemination anoestrus (estrus not detected until 8 mo of age). The aim of this study was to provide the answer to the following question: do the culling Gilts reach cyclic ovarian activity at all? One hundred seventy five culled Gilts in which external estrus manifestations were not detected by 8 mo of age were sacrificed and their reproductive organs were examined for determination of sexual maturity (ovaries exhibiting pre-ovulatory follicles 8 to 11 mm in diameter, corpora hemorrhagica, corpora lutea and corpora albicantia). Uterine weights and horn length were also determined. Functional ovaries were observed in 107 (61.1%) examined Gilts, with 62 animals having one and 45 having two puberty ovarian cycles (57.9% and 42.1%, respectively). Pathomorphological changes which could result in prolonged pre-insemination anoestrus were not observed on the reproductive organs of sexually mature Gilts. Our results indicate that most of the culling Gilts have reached cyclic ovarian activity. The main reason for culling due to the absence of external estrus manifestations in sexually mature Gilts could be inadequate estrus detection technology.

Darko Bosnjak - One of the best experts on this subject based on the ideXlab platform.

  • ovarian reaction and estrus manifestation in delayed puberty Gilts after treatment with equine chorionic gonadotropin
    Reproductive Biology and Endocrinology, 2012
    Co-Authors: Ivan Stancic, Darko Bosnjak, Ivan Radovic, Blagoje Stancic, R B Harvey, Robin C Anderson
    Abstract:

    Background: Prolonged pre-insemination anestrus (i.e. delayed puberty) is a major contributing factor for culling up to 30% of the replacement Gilts at large breeding farm units in Vojvodina. It is imperative to determine if these Gilts are acyclic (prepubertal) or cyclic, but just fail to exhibit behavioural estrus. Recent investigations demonstrate that treatment with equine chorionic gonadotropin (eCG) can increase the diestrous phase duration in sexually mature Gilts. Based on these finding, the aim of the present studies was to determine the reproductive status of delayed puberty Gilts following injection with eCG. Methods: Two experiments were conducted on a swine breeding farm in Vojvodina. In Exp. 1, 20 prepubertal (acyclic) Gilts, and 120 sexually mature (cyclic) Gilts were injected with a single injection of 400 IU eCG+200 IU human chorionic gonadotropin (hCG) or with 1000 IU eCG (cyclic Gilts), at d5, d11 or d17 after spontaneous estrus detection, to determine their ovarian reaction and induced estrus manifestation. In Exp. 2, sixty delayed puberty Gilts (estrus not detected until 8 month of age, av. 258 days) were culled from breeding herd and slaughtered to determine their reproductive status based on ovarian anatomical features. The second group of Gilts (n=60) was treated with a single 1000 IU eCG injection to determine their reproductive status, based on the interval between eCG injection to estrus detection and duration. The data were analyzed by descriptive statistics, t-test, analysis of variance and Duncan’s test in the software package Statistics 10 th . Results: Ovulations were induced in 90% of acyclic (sexually immature) and, on average, 93.3% of cyclic (sexually mature) Gilts after the eCG injection. On average, 4 days after the eCG injection, estrus was detected in 85% of the treated acyclic (sexually immature) Gilts and in 95% (19/20) of the cyclic (sexually mature) Gilts, treated with eCG on day 17 after spontaneous estrus detection. The interval from eCG to induced estrus detection was prolonged (av. 25 days) in 95% (19/20) of the sexually mature Gilts treated with eCG on day 5 and in 90% (18/20) of Gilts treated on day 11 after spontaneous estrus detection (Exp. 1). Forty anestrous Gilts reached cyclic pubertal ovarian activity. Estrus manifestation was detected in 56 Gilts (93.3% of the total 60 treated prolonged anestrous Gilts, av. 259 days of age), after a single 1000 IU eCG injection. Thirty-four Gilts (60.7% of the total Gilts in estrus) with prolonged eCG to estrus interval (av. 24.7 days) were considered spontaneously cyclic (sexually mature), but behaviourally anestrous before treatment. The remaining 22 (39.3% of the total Gilts in estrus) were considered truly sexually immature (acyclic) before the treatment or were eCG injected in the late luteal or proestrous phase of spontaneous estrous cycle (Exp. 2). (Continued on next page)

  • ovarian reaction and estrus manifestation in delayed puberty Gilts after treatment with equine chorionic gonadotropin
    Reproductive Biology and Endocrinology, 2012
    Co-Authors: Ivan Stancic, Darko Bosnjak, Ivan Radovic, Blagoje Stancic, R B Harvey, Robin C Anderson
    Abstract:

    Background: Prolonged pre-insemination anestrus (i.e. delayed puberty) is a major contributing factor for culling up to 30% of the replacement Gilts at large breeding farm units in Vojvodina. It is imperative to determine if these Gilts are acyclic (prepubertal) or cyclic, but just fail to exhibit behavioural estrus. Recent investigations demonstrate that treatment with equine chorionic gonadotropin (eCG) can increase the diestrous phase duration in sexually mature Gilts. Based on these finding, the aim of the present studies was to determine the reproductive status of delayed puberty Gilts following injection with eCG. Methods: Two experiments were conducted on a swine breeding farm in Vojvodina. In Exp. 1, 20 prepubertal (acyclic) Gilts, and 120 sexually mature (cyclic) Gilts were injected with a single injection of 400 IU eCG+200 IU human chorionic gonadotropin (hCG) or with 1000 IU eCG (cyclic Gilts), at d5, d11 or d17 after spontaneous estrus detection, to determine their ovarian reaction and induced estrus manifestation. In Exp. 2, sixty delayed puberty Gilts (estrus not detected until 8 month of age, av. 258 days) were culled from breeding herd and slaughtered to determine their reproductive status based on ovarian anatomical features. The second group of Gilts (n=60) was treated with a single 1000 IU eCG injection to determine their reproductive status, based on the interval between eCG injection to estrus detection and duration. The data were analyzed by descriptive statistics, t-test, analysis of variance and Duncan’s test in the software package Statistics 10 th . Results: Ovulations were induced in 90% of acyclic (sexually immature) and, on average, 93.3% of cyclic (sexually mature) Gilts after the eCG injection. On average, 4 days after the eCG injection, estrus was detected in 85% of the treated acyclic (sexually immature) Gilts and in 95% (19/20) of the cyclic (sexually mature) Gilts, treated with eCG on day 17 after spontaneous estrus detection. The interval from eCG to induced estrus detection was prolonged (av. 25 days) in 95% (19/20) of the sexually mature Gilts treated with eCG on day 5 and in 90% (18/20) of Gilts treated on day 11 after spontaneous estrus detection (Exp. 1). Forty anestrous Gilts reached cyclic pubertal ovarian activity. Estrus manifestation was detected in 56 Gilts (93.3% of the total 60 treated prolonged anestrous Gilts, av. 259 days of age), after a single 1000 IU eCG injection. Thirty-four Gilts (60.7% of the total Gilts in estrus) with prolonged eCG to estrus interval (av. 24.7 days) were considered spontaneously cyclic (sexually mature), but behaviourally anestrous before treatment. The remaining 22 (39.3% of the total Gilts in estrus) were considered truly sexually immature (acyclic) before the treatment or were eCG injected in the late luteal or proestrous phase of spontaneous estrous cycle (Exp. 2). (Continued on next page)