Analysis of nuclear maturation, DNA damage and repair gene expression of bovine oocyte and cumulus cells submitted to ionizing radiation'

Radiotherapy causes destruction of tumor cells, but also threatens the integrity and survival of surrounding normal cells. Then, woman submitted to irradiation for cancer treatment may present permanent ovary damage, resulting in impaired fertility. The objective of this study was to investigate the effects of therapeutic doses of ionizing radiation (IR), used for ovarian cancer treatment in humans, on bovine cumulus-oocyte complexes (COCs) as experimental model. Bovine ovaries were exposed to 0.9 Gy, 1.8 Gy, 3.6 Gy or 18.6 Gy IR, and then COCs were collected and used to evaluate: (a) oocyte nuclear maturation; (b) presence of phosphorylated H2A.X (γH2AX), as an indicator of DNA double-strand breaks (DSBs); and (c) expression of genes involved in DNA repair (TP53BP1, RAD52, ATM, XRCC6 and XRCC5) and apoptosis (BAX). The radiation doses tested in this study had no detrimental effects on nuclear maturation and did not increase γH2AX in the oocytes. However, IR treatment altered the mRNA abundance of RAD52 (RAD52 homolog, DNA repair protein) and BAX (BCL2-associated X protein). We conclude that although IR doses had no apparent effect on oocyte nuclear maturation and DNA damage, molecular pathways involved in DNA repair and apoptosis were affected by IR exposure in cumulus cells.(AU)

Transforming growth factor-beta family members are regulated during induced luteolysis in cattle

The transforming growth factors beta (TGFβ) are local factors produced by ovarian cells which, after binding to their receptors, regulate follicular deviation and ovulation. However, their regulation and function during corpus luteum (CL) regression has been poorly investigated. The present study evaluated the mRNA regulation of some TGFβ family ligands and their receptors in the bovine CL during induced luteolysis in vivo. On day 10 of the estrous cycle, cows received an injection of prostaglandin F2α (PGF) and luteal samples were obtained from separate groups of cows (n= 4-5 cows per time-point) at 0, 2, 12, 24 or 48 h after treatment. Since TGF beta family comprises more than 30 ligands, we focused in some candidates genes such as activin receptors (ACVR-1A, -1B, -2A, -2B) AMH, AMHR2, BMPs (BMP-1, -2, -3, -4, -6 and -7), BMP receptors (BMPR-1A, -1B and -2), inhibin subunits (INH-A, -BA, -BB) and betaglycan (TGFBR3). The mRNA levels of BMP4, BMP6 and INHBA were higher at 2 h after PGF administration (P<0.05) in comparison to 0 h. The relative mRNA abundance of BMP1, BMP2, BMP3, BMP4, BMP6, ACVR1B, INHBA and INHBB was upregulated up to 12 h post PGF (P<0.05). On the other hand, TGFBR3 mRNA that codes for a reservoir of ligands that bind to TGF-beta receptors, was lower at 48 h. In conclusion, findings from this study demonstrated that genes encoding several TGFβ family members are expressed in a time-specific manner after PGF administration.(AU)

Transforming growth factor-beta family members are regulated during induced luteolysis in cattle

The transforming growth factors beta (TGFβ) are local factors produced by ovarian cells which, after binding to their receptors, regulate follicular deviation and ovulation. However, their regulation and function during corpus luteum (CL) regression has been poorly investigated. The present study evaluated the mRNA regulation of some TGFβ family ligands and their receptors in the bovine CL during induced luteolysis in vivo. On day 10 of the estrous cycle, cows received an injection of prostaglandin F2α (PGF) and luteal samples were obtained from separate groups of cows (n= 4-5 cows per time-point) at 0, 2, 12, 24 or 48 h after treatment. Since TGF beta family comprises more than 30 ligands, we focused in some candidates genes such as activin receptors (ACVR-1A, -1B, -2A, -2B) AMH, AMHR2, BMPs (BMP-1, -2, -3, -4, -6 and -7), BMP receptors (BMPR-1A, -1B and -2), inhibin subunits (INH-A, -BA, -BB) and betaglycan (TGFBR3). The mRNA levels of BMP4, BMP6 and INHBA were higher at 2 h after PGF administration (P<0.05) in comparison to 0 h. The relative mRNA abundance of BMP1, BMP2, BMP3, BMP4, BMP6, ACVR1B, INHBA and INHBB was upregulated up to 12 h post PGF (P<0.05). On the other hand, TGFBR3 mRNA that codes for a reservoir of ligands that bind to TGF-beta receptors, was lower at 48 h. In conclusion, findings from this study demonstrated that genes encoding several TGFβ family members are expressed in a time-specific manner after PGF administration.

Laparoscopic ovum pick-up for in vitro embryo production from dairy bovine andbuffalo calves

Laparoscopic ovum pick-up (LOPU) conducted on bovine and buffalo calves of 2-6-month of age, followed by in vitro embryo production and transfer into synchronous adult recipients, is a powerful tool for accelerated genetic gain and early dissemination of top genetics. In its current state, the technology is characterized by higher oocyte recovery rates, lower oocyte-to-embryo yields, and similar pregnancy and term development rates compared with adult counterparts. Improvements in oocyte competence have been made in recent years mainly through gonadotropin stimulation protocols tailored for prepubertal donors. These advances have brought the technology to the point of been apt for commercial application. However, future research must focus on increasing the proportion of fully competent oocytes recovered from calves thereby further empowering the role this technology platform can play in programs for accelerated dissemination of superior genetics.

Laparoscopic ovum pick-up for in vitro embryo production from dairy bovine andbuffalo calves

Laparoscopic ovum pick-up (LOPU) conducted on bovine and buffalo calves of 2-6-month of age, followed by in vitro embryo production and transfer into synchronous adult recipients, is a powerful tool for accelerated genetic gain and early dissemination of top genetics. In its current state, the technology is characterized by higher oocyte recovery rates, lower oocyte-to-embryo yields, and similar pregnancy and term development rates compared with adult counterparts. Improvements in oocyte competence have been made in recent years mainly through gonadotropin stimulation protocols tailored for prepubertal donors. These advances have brought the technology to the point of been apt for commercial application. However, future research must focus on increasing the proportion of fully competent oocytes recovered from calves thereby further empowering the role this technology platform can play in programs for accelerated dissemination of superior genetics.(AU)

Methods to study ovarian function in monovulatory species using the cow as a model

In this review, we discuss the utility of the cow as an in vivo model to study the regulation of ovarian functions in monovular species. It is increasingly becoming clear that besides endocrine control locally produced factors play pivotal roles during dominant follicle selection, oocyte maturation, ovulation and luteolysis. Although in vitro culture systems have been used to study these processes, definitive understanding the interactions between endocrine and local factors requires appropriate in vivo models. Most of the experimental approaches to study ovarian functionsin vivo in large animals are based on the use of ultrasonography and considerable progress in this field has been made during the last thirty years. It has been shown that cows are an excellent model to collect samples (e.g., follicular fluid, granulosa cells, oocytes) from live animals at specific stages of follicular development in order to study mechanisms of intrafollicular factors in a physiological endocrine environment. In addition to support fundamental studies, the cow model has contributed immensely to the refinement of assisted reproductive technologies, which are now widely used not only in farm animals but also in humans.

Methods to study ovarian function in monovulatory species using the cow as a model

In this review, we discuss the utility of the cow as an in vivo model to study the regulation of ovarian functions in monovular species. It is increasingly becoming clear that besides endocrine control locally produced factors play pivotal roles during dominant follicle selection, oocyte maturation, ovulation and luteolysis. Although in vitro culture systems have been used to study these processes, definitive understanding the interactions between endocrine and local factors requires appropriate in vivo models. Most of the experimental approaches to study ovarian functionsin vivo in large animals are based on the use of ultrasonography and considerable progress in this field has been made during the last thirty years. It has been shown that cows are an excellent model to collect samples (e.g., follicular fluid, granulosa cells, oocytes) from live animals at specific stages of follicular development in order to study mechanisms of intrafollicular factors in a physiological endocrine environment. In addition to support fundamental studies, the cow model has contributed immensely to the refinement of assisted reproductive technologies, which are now widely used not only in farm animals but also in humans.(AU)

Delaying farrowing using intravaginal devices impregnated with progestagen does not affect the proportion of piglets born alive

The objective of this study was to evaluate the efficiency of progestagen intravaginal devices (IVDs) in preventing parturition in sows by determining the effect of delaying parturition on the alive/total born piglets ratio. Evaluations of IVDs containing 0.5, 1.0 or 1.5g progesterone (P4) showed they were not effective in delaying parturition at any dosage tested. In a second experiment, seventy-five sows at day 112 of pregnancy were equally distributed (n=15 per group) in the following treatments: prostaglandin (PGF2; 250µg sodium cloprostenol; control group) or PGF2 and simultaneous insertion of an IVD containing medroxyprogesterone acetate (MPA) for 48h. Control sows initiated labor 27.7±1.6h after PGF2 injection. The mean time (±SEM) between PGF2 administration and parturition was 72.1±8.8h, 72.7±3.8h, 82.7±7.1h and 81.8±3.5h for MPA 100, 200, 400 and 800mg, respectively, differing from control group (P 0.05). To evaluate the effect of delaying parturition on the alive/total born piglets ratio at birth, sows between days 109 and 112 of gestation received IVDs containing 800mg MPA (on Thursdays) for 72h to prevent parturition in weekends and then were treated with PGF2 at the time of device withdrawal (on Sundays). The alive/total born piglets ratio was 89.0±1.6, 90.1±1.2 and 89.0±1.5% for control (Normal group; n=57 sows), PGF2-induced (Induced group; n=57 sows), and IVD+PGF2-induced (MPA800 group, n=56 sows) groups, respectively (P>0.05). These findings confirm that IVDs impregnated with MPA can effectively prevent parturition in sows without affecting the alive/total born piglets ratio and therefore represent an alternative to avoid weekend farrowing in swine herds.

O objetivo do presente estudo foi avaliar a eficiência de dispositivos intravaginais (DIVs) contendo progestágeno na prevenção do parto e determinar o efeito do atraso do parto sobre a proporção de leitões vivos/nascidos totais. DIVs contendo 0,5, 1,0 ou 1,5g de progesterona (P4) não foram eficientes na prevenção do parto em nenhuma das doses. No experimento 2, setenta e cinco porcas aos 112 dias de gestação foram equilibradamente distribuídas (n=15 por grupo) nos seguintes tratamentos: prostaglandina (PGF2; 250µg cloprostenol sódico; grupo controle) ou PGF2 e simultânea inserção de DIV contendo acetato de medroxiprogesterona (MAP) por 48h. Fêmeas do grupo controle iniciaram o parto 27,7±1,6h após injeção de PGF2. O tempo médio entre a administração de PGF2 e início do parto foi 72,1±8,8h, 72,7±3,8h, 82,7±7,1h e 81,8±3,5h para os grupos MAP 100, 200, 400 e 800mg, respectivamente, diferindo do grupo controle (P 0,05). Para avaliar o efeito da inibição do parto sobre a proporção de leitões nascidos vivos, porcas entre 109 e 112 dias de gestação receberam DIVs contendo 800mg MAP (quintas-feiras) por 72h para prevenir o parto aos finais de semana e foram tratadas com PGF2 no momento da retirada dos DIV (aos domingos). A razão leitões vivos/nascidos totais foi 89,0±1,6, 90,1±1,2 e 89,0±1,5% nos grupos controle (Normal; n=57 porcas), induzido com PGF2 (Induzido; n=57 porcas) e PGF2+DIV (MPA800; n=56 porcas), respectivamente (P>0,05). Esses resultados confirmam que DIVs contendo MAP podem efetivamente inibir o início do parto em porcas sem afetar a proporção de leitões nascidos vivos e, portanto, representam uma alternativa para evitar partos aos finais de semana.

Delaying farrowing using intravaginal devices impregnated with progestagen does not affect the proportion of piglets born alive

The objective of this study was to evaluate the efficiency of progestagen intravaginal devices (IVDs) in preventing parturition in sows by determining the effect of delaying parturition on the alive/total born piglets ratio. Evaluations of IVDs containing 0.5, 1.0 or 1.5g progesterone (P4) showed they were not effective in delaying parturition at any dosage tested. In a second experiment, seventy-five sows at day 112 of pregnancy were equally distributed (n=15 per group) in the following treatments: prostaglandin (PGF2; 250µg sodium cloprostenol; control group) or PGF2 and simultaneous insertion of an IVD containing medroxyprogesterone acetate (MPA) for 48h. Control sows initiated labor 27.7±1.6h after PGF2 injection. The mean time (±SEM) between PGF2 administration and parturition was 72.1±8.8h, 72.7±3.8h, 82.7±7.1h and 81.8±3.5h for MPA 100, 200, 400 and 800mg, respectively, differing from control group (P 0.05). To evaluate the effect of delaying parturition on the alive/total born piglets ratio at birth, sows between days 109 and 112 of gestation received IVDs containing 800mg MPA (on Thursdays) for 72h to prevent parturition in weekends and then were treated with PGF2 at the time of device withdrawal (on Sundays). The alive/total born piglets ratio was 89.0±1.6, 90.1±1.2 and 89.0±1.5% for control (Normal group; n=57 sows), PGF2-induced (Induced group; n=57 sows), and IVD+PGF2-induced (MPA800 group, n=56 sows) groups, respectively (P>0.05). These findings confirm that IVDs impregnated with MPA can effectively prevent parturition in sows without affecting the alive/total born piglets ratio and therefore represent an alternative to avoid weekend farrowing in swine herds.

O objetivo do presente estudo foi avaliar a eficiência de dispositivos intravaginais (DIVs) contendo progestágeno na prevenção do parto e determinar o efeito do atraso do parto sobre a proporção de leitões vivos/nascidos totais. DIVs contendo 0,5, 1,0 ou 1,5g de progesterona (P4) não foram eficientes na prevenção do parto em nenhuma das doses. No experimento 2, setenta e cinco porcas aos 112 dias de gestação foram equilibradamente distribuídas (n=15 por grupo) nos seguintes tratamentos: prostaglandina (PGF2; 250µg cloprostenol sódico; grupo controle) ou PGF2 e simultânea inserção de DIV contendo acetato de medroxiprogesterona (MAP) por 48h. Fêmeas do grupo controle iniciaram o parto 27,7±1,6h após injeção de PGF2. O tempo médio entre a administração de PGF2 e início do parto foi 72,1±8,8h, 72,7±3,8h, 82,7±7,1h e 81,8±3,5h para os grupos MAP 100, 200, 400 e 800mg, respectivamente, diferindo do grupo controle (P 0,05). Para avaliar o efeito da inibição do parto sobre a proporção de leitões nascidos vivos, porcas entre 109 e 112 dias de gestação receberam DIVs contendo 800mg MAP (quintas-feiras) por 72h para prevenir o parto aos finais de semana e foram tratadas com PGF2 no momento da retirada dos DIV (aos domingos). A razão leitões vivos/nascidos totais foi 89,0±1,6, 90,1±1,2 e 89,0±1,5% nos grupos controle (Normal; n=57 porcas), induzido com PGF2 (Induzido; n=57 porcas) e PGF2+DIV (MPA800; n=56 porcas), respectivamente (P>0,05). Esses resultados confirmam que DIVs contendo MAP podem efetivamente inibir o início do parto em porcas sem afetar a proporção de leitões nascidos vivos e, portanto, representam uma alternativa para evitar partos aos finais de semana.

Delaying farrowing using intravaginal devices impregnated with progestagen does not affect the proportion of piglets born alive

The objective of this study was to evaluate the efficiency of progestagen intravaginal devices (IVDs) in preventing parturition in sows by determining the effect of delaying parturition on the alive/total born piglets ratio. Evaluations of IVDs containing 0.5, 1.0 or 1.5g progesterone (P4) showed they were not effective in delaying parturition at any dosage tested. In a second experiment, seventy-five sows at day 112 of pregnancy were equally distributed (n=15 per group) in the following treatments: prostaglandin (PGF2; 250µg sodium cloprostenol; control group) or PGF2 and simultaneous insertion of an IVD containing medroxyprogesterone acetate (MPA) for 48h. Control sows initiated labor 27.7±1.6h after PGF2 injection. The mean time (±SEM) between PGF2 administration and parturition was 72.1±8.8h, 72.7±3.8h, 82.7±7.1h and 81.8±3.5h for MPA 100, 200, 400 and 800mg, respectively, differing from control group (P 0.05). To evaluate the effect of delaying parturition on the alive/total born piglets ratio at birth, sows between days 109 and 112 of gestation received IVDs containing 800mg MPA (on Thursdays) for 72h to prevent parturition in weekends and then were treated with PGF2 at the time of device withdrawal (on Sundays). The alive/total born piglets ratio was 89.0±1.6, 90.1±1.2 and 89.0±1.5% for control (Normal group; n=57 sows), PGF2-induced (Induced group; n=57 sows), and IVD+PGF2-induced (MPA800 group, n=56 sows) groups, respectively (P>0.05). These findings confirm that IVDs impregnated with MPA can effectively prevent parturition in sows without affecting the alive/total born piglets ratio and therefore represent an alternative to avoid weekend farrowing in swine herds.

O objetivo do presente estudo foi avaliar a eficiência de dispositivos intravaginais (DIVs) contendo progestágeno na prevenção do parto e determinar o efeito do atraso do parto sobre a proporção de leitões vivos/nascidos totais. DIVs contendo 0,5, 1,0 ou 1,5g de progesterona (P4) não foram eficientes na prevenção do parto em nenhuma das doses. No experimento 2, setenta e cinco porcas aos 112 dias de gestação foram equilibradamente distribuídas (n=15 por grupo) nos seguintes tratamentos: prostaglandina (PGF2; 250µg cloprostenol sódico; grupo controle) ou PGF2 e simultânea inserção de DIV contendo acetato de medroxiprogesterona (MAP) por 48h. Fêmeas do grupo controle iniciaram o parto 27,7±1,6h após injeção de PGF2. O tempo médio entre a administração de PGF2 e início do parto foi 72,1±8,8h, 72,7±3,8h, 82,7±7,1h e 81,8±3,5h para os grupos MAP 100, 200, 400 e 800mg, respectivamente, diferindo do grupo controle (P 0,05). Para avaliar o efeito da inibição do parto sobre a proporção de leitões nascidos vivos, porcas entre 109 e 112 dias de gestação receberam DIVs contendo 800mg MAP (quintas-feiras) por 72h para prevenir o parto aos finais de semana e foram tratadas com PGF2 no momento da retirada dos DIV (aos domingos). A razão leitões vivos/nascidos totais foi 89,0±1,6, 90,1±1,2 e 89,0±1,5% nos grupos controle (Normal; n=57 porcas), induzido com PGF2 (Induzido; n=57 porcas) e PGF2+DIV (MPA800; n=56 porcas), respectivamente (P>0,05). Esses resultados confirmam que DIVs contendo MAP podem efetivamente inibir o início do parto em porcas sem afetar a proporção de leitões nascidos vivos e, portanto, representam uma alternativa para evitar partos aos finais de semana.

Gonadotrofina coriônica eqüina: purificação, caracterização e resposta ovariana em ovinos e suínos

Equine chorionic gonadotrophin (eCG) was purified and characterized with respect to its purity and bionological activity. The purity of four preparations was determined by electrophoresis, and the biological activity by increasing of the ovarian weight ot immature female rats (40-50g) and induction ot ovulation of ewes and gilts. Electrophoretic analysis revealed three polipeptidic bands. The mean biological activity was 313UI/mg of protein. Sixty-five ewes, not in reproductive season, were divided randomly in two groups that received vaginal pessaries impregnated with medroxiprogesterone acetato for 11 to 14 days. In treatment I, ewes (n = 55) were injected (IM) with 500UI of puritied eCG at the moment of pessaries withdraw, while in treatment II, the ewes (n = 10) received 500UI of comercial eCG. The results observed were 2.1 ± 0.3 and 1.8 ± 0.3 ovulations (P > 0.05) for treatments I and II, respectively. One hundred-twenty gilts, with mean weight of 87.2kg, were divided m two treatments. The animals in treatment I (90 gilts) received 500UI of puntied eCG and, 72 hours later, 500UI of hCG (human chorionic gonadotrophin). In treatment II hormones were not injected. The results observed were 25.9 ± 22.2 and 0.0 corpora lutea (P 0.001) for treatments I and II, respectively. These results demonstrated that the eCG purified has purity and biological activity similar to the comercial product used as control, and that it is efficient in inducing ovarian activity in ewes and gilts.

A gonadotrofina coriônica equina (eCG) foi purificada e caracterizada com respeito ao grau de pureza e atividade biológica. A pureza de quatro preparações foi determinada por eletroforese e a atividade biológica pelo incremento do peso ovariano de ratas imaturas (40 - 50g) e pela indução de ovulação em ovelhas e leitoas. A análise eletroforética revelou a presença de três bandas polipeptídicas. A atividade biológica media foi de 313 UI/mg de proteína. Sessenta e cinco (65) ovelhas, fora da estação reprodutiva, foram divididas ao acaso em dois grupos os quais receberam implantes vaginais de esponjas impregnadas com acetato de medroxiprogesterona por um período de l l a 14 dias. No grupo I (55 ovelhas), foram injetadas (IM) 500UI do eCG purificado no momento da retirada das esponjas, enquanto que no grupo II (10 ovelhas) foram injetadas 500UI de eCG comercial. Uma semana após a aplicação do eCG as ovelhas foram submetidas a um exame laparoscópico para avaliar o número de ovulações. Obteve-se uma média de 2,1 ± 0,3 e 1,8 ± 0,3 ovulações (P>0,05) para as ovelhas dos grupos I e II, respectivamente. De 120 leitoas pré-púberes, com peso médio de 87,2 kg, 90 (grupo I) foram injetadas com 500UI do eCG purificado e, às 72 horas, 500UI de hCG (gonadotrofina coriônica humana), e 30 leitoas (grupo II) não receberam injeção hormonal. Observou-se a presença de 25,9 ± 22,2 e 0,0 corpora lutea (P 0,001), nos grupos I e II, respectivamente. Estes resultados demonstraram que o PMSG purificado apresenta pureza e atividade biológica similares ao produto comercial utilizado como controle e que é eficiente para induzir atividade ovariana em ovinos e suínos.

Gonadotrofina coriônica eqüina: purificação, caracterização e resposta ovariana em ovinos e suínos

Equine chorionic gonadotrophin (eCG) was purified and characterized with respect to its purity and bionological activity. The purity of four preparations was determined by electrophoresis, and the biological activity by increasing of the ovarian weight ot immature female rats (40-50g) and induction ot ovulation of ewes and gilts. Electrophoretic analysis revealed three polipeptidic bands. The mean biological activity was 313UI/mg of protein. Sixty-five ewes, not in reproductive season, were divided randomly in two groups that received vaginal pessaries impregnated with medroxiprogesterone acetato for 11 to 14 days. In treatment I, ewes (n = 55) were injected (IM) with 500UI of puritied eCG at the moment of pessaries withdraw, while in treatment II, the ewes (n = 10) received 500UI of comercial eCG. The results observed were 2.1 ± 0.3 and 1.8 ± 0.3 ovulations (P > 0.05) for treatments I and II, respectively. One hundred-twenty gilts, with mean weight of 87.2kg, were divided m two treatments. The animals in treatment I (90 gilts) received 500UI of puntied eCG and, 72 hours later, 500UI of hCG (human chorionic gonadotrophin). In treatment II hormones were not injected. The results observed were 25.9 ± 22.2 and 0.0 corpora lutea (P 0.001) for treatments I and II, respectively. These results demonstrated that the eCG purified has purity and biological activity similar to the comercial product used as control, and that it is efficient in inducing ovarian activity in ewes and gilts.

A gonadotrofina coriônica equina (eCG) foi purificada e caracterizada com respeito ao grau de pureza e atividade biológica. A pureza de quatro preparações foi determinada por eletroforese e a atividade biológica pelo incremento do peso ovariano de ratas imaturas (40 - 50g) e pela indução de ovulação em ovelhas e leitoas. A análise eletroforética revelou a presença de três bandas polipeptídicas. A atividade biológica media foi de 313 UI/mg de proteína. Sessenta e cinco (65) ovelhas, fora da estação reprodutiva, foram divididas ao acaso em dois grupos os quais receberam implantes vaginais de esponjas impregnadas com acetato de medroxiprogesterona por um período de l l a 14 dias. No grupo I (55 ovelhas), foram injetadas (IM) 500UI do eCG purificado no momento da retirada das esponjas, enquanto que no grupo II (10 ovelhas) foram injetadas 500UI de eCG comercial. Uma semana após a aplicação do eCG as ovelhas foram submetidas a um exame laparoscópico para avaliar o número de ovulações. Obteve-se uma média de 2,1 ± 0,3 e 1,8 ± 0,3 ovulações (P>0,05) para as ovelhas dos grupos I e II, respectivamente. De 120 leitoas pré-púberes, com peso médio de 87,2 kg, 90 (grupo I) foram injetadas com 500UI do eCG purificado e, às 72 horas, 500UI de hCG (gonadotrofina coriônica humana), e 30 leitoas (grupo II) não receberam injeção hormonal. Observou-se a presença de 25,9 ± 22,2 e 0,0 corpora lutea (P 0,001), nos grupos I e II, respectivamente. Estes resultados demonstraram que o PMSG purificado apresenta pureza e atividade biológica similares ao produto comercial utilizado como controle e que é eficiente para induzir atividade ovariana em ovinos e suínos.