Ultrasound monitoring of the uterus and ovaries of dominant and subordinate females of yellow-breasted capuchin (Sapajus xanthosternos) and robust tufted capuchin (Sapajus robustus) in captive colonies during the ovarian cycle and anestrus periods / Acompanhamento ultrassonográfico do útero e ovários de fêmeas dominantes e subordinadas de macacos-prego-do-peito-amarelo (Sapajus xanthosternos) e macacos-prego-de-crista (Sapajus robustus) em colônias cativas, durante o ciclo ovariano e períodos de anestro

The yellow-breasted capuchin (Sapajus xanthosternos) and robust tufted capuchin (Sapajus robustus) are endangered species due to destruction of their natural habitat and predatory chase. However, it is still necessary to elucidate some details of their reproductive physiology in order to obtain better indices in the assisted reproduction of these species. This study aimed to evaluate the ovarian cycle of 13 dominant and subordinate females of S. xanthosternos (n=8) and S. robustus (n=5) using sagittal and transversally scanned ultrasound of their uterus and ovaries. Sonograms were performed every seven days for two months. The ovarian cycle phase and anestrous condition were confirmed by colpocytology. Our results showed different uterine parameters (craniocaudal diameter, dorso-ventral diameter, and transverse diameter) (P<0.05) between anestrous subordinate females and other ovarian cycle phases and social classes. The mean of uterine volume was higher in dominant females than subordinate females in all cycle phases (P<0.05), except in follicular phase. During anestrus, endometrial width was smaller in subordinate females than in dominant females (P<0.05). Subordinate females showed differences in endometrial measures (P<0.05) between anestrous period and follicular and luteal periods. Ovarian measures in dominant females were higher than in subordinate females only during anestrus (P<0.05). In the subordinate females, ovarian parameters were different (P<0.05) between anestrus and follicular and luteal phases. Dominant females showed higher volume of right ovary compared to volume of the left ovary during anestrus and follicular phase (P<0.05). Follicles and corpus luteum were distinguished by ultrasonography in most exams (86.11%). During anestrus, measurable ovarian structures were not observed in both ovaries in dominant and subordinate females. In conclusion, the methodology used in this study allowed to evaluate the ovarian cycle in S. xanthosternos e S. robustus females and that cycle phase/anestrus and social class of the female influenced the size of the uterus and ovaries.(AU)

O macaco-prego-do-peito-amarelo (Sapajus xanthosternos) e o macaco-prego-de-crista (Sapajus robustus) encontram-se em risco de extinção devido a destruição do seu habitat e a caça predatória. Porém, ainda necessita-se elucidar alguns detalhes de sua fisiologia reprodutiva, para obterem-se melhores índices por meio de reprodução assistida. Sendo assim, o objetivo deste trabalho foi acompanhar o ciclo ovariano de 13 fêmeas dominantes e subordinadas de S. xanthosternos (n=8) e S. robustus (n=5) por meio de cortes ultrassonográficos sagitais e transversais do útero e dos ovários. Estas fêmeas foram examinadas uma vez por semana durante dois meses. A fase do ciclo ovariano/anestro foi confirmada pela colpocitologia. Os resultados da pesquisa demonstrou diferença significativa (P<0,05) relacionada ao diâmetro crânio-caudal, diâmetro dorso-ventral e diâmetro transversal entre as fêmeas subordinadas em anestro com todas as outras fases do ciclo ovariano e classes sociais. A média do volume uterino foi maior nas fêmeas dominantes que nas subordinadas em todas as fases do ciclo (P<0,05) a exceção da fase folicular. A largura endometrial, durante o período de anestro, foi menor nas fêmeas subordinadas quando comparada às dominantes (P<0,05). Nas fêmeas subordinadas, houve diferenças (P<0,05) nas mensurações endometriais entre o período de anestro e das fases folicular e lútea. Quanto aos ovários, as médias das medidas observadas nas fêmeas dominantes foram superiores as das subordinadas durante o anestro (P<0,05). As médias das medidas das variáveis ovarianas das fêmeas subordinadas apresentaram diferenças entre o anestro e as fases folicular e lútea (P<0,05). Nas fêmeas dominantes o volume do ovário direito foi maior que o do ovário esquerdo durante o anestro e na fase folicular (P<0,05). Folículos e corpos lúteos foram diferenciados pela ultrassonografia na maioria das coletas (86,11%). Durante o anestro não foram observadas estruturas ovarianas mensuráveis nos ovários em ambas as classes sociais. Concluiu-se que a metodologia empregada neste estudo permitiu o acompanhamento do ciclo ovariano das fêmeas S. xanthosternos e S. robustus e que as fases do ciclo/anestro e a classe social das fêmeas influenciaram as medidas do útero e ovários.(AU)

Ultrasound monitoring of the uterus and ovaries of dominant and subordinate females of yellow-breasted capuchin (Sapajus xanthosternos) and robust tufted capuchin (Sapajus robustus) in captive colonies during the ovarian cycle and anestrus periods / Acompanhamento ultrassonográfico do útero e ovários de fêmeas dominantes e subordinadas de macacos-prego-do-peito-amarelo (Sapajus xanthosternos) e macacos-prego-de-crista (Sapajus robustus) em colônias cativas, durante o ciclo ovariano e períodos de anestro

The yellow-breasted capuchin (Sapajus xanthosternos) and robust tufted capuchin (Sapajus robustus) are endangered species due to destruction of their natural habitat and predatory chase. However, it is still necessary to elucidate some details of their reproductive physiology in order to obtain better indices in the assisted reproduction of these species. This study aimed to evaluate the ovarian cycle of 13 dominant and subordinate females of S. xanthosternos (n=8) and S. robustus (n=5) using sagittal and transversally scanned ultrasound of their uterus and ovaries. Sonograms were performed every seven days for two months. The ovarian cycle phase and anestrous condition were confirmed by colpocytology. Our results showed different uterine parameters (craniocaudal diameter, dorso-ventral diameter, and transverse diameter) (P<0.05) between anestrous subordinate females and other ovarian cycle phases and social classes. The mean of uterine volume was higher in dominant females than subordinate females in all cycle phases (P<0.05), except in follicular phase. During anestrus, endometrial width was smaller in subordinate females than in dominant females (P<0.05). Subordinate females showed differences in endometrial measures (P<0.05) between anestrous period and follicular and luteal periods. Ovarian measures in dominant females were higher than in subordinate females only during anestrus (P<0.05). In the subordinate females, ovarian parameters were different (P<0.05) between anestrus and follicular and luteal phases. Dominant females showed higher volume of right ovary compared to volume of the left ovary during anestrus and follicular phase (P<0.05). Follicles and corpus luteum were distinguished by ultrasonography in most exams (86.11%). During anestrus, measurable ovarian structures were not observed in both ovaries in dominant and subordinate females. In conclusion, the methodology used in this study allowed to evaluate the ovarian cycle in S. xanthosternos e S. robustus females and that cycle phase/anestrus and social class of the female influenced the size of the uterus and ovaries.(AU)

O macaco-prego-do-peito-amarelo (Sapajus xanthosternos) e o macaco-prego-de-crista (Sapajus robustus) encontram-se em risco de extinção devido a destruição do seu habitat e a caça predatória. Porém, ainda necessita-se elucidar alguns detalhes de sua fisiologia reprodutiva, para obterem-se melhores índices por meio de reprodução assistida. Sendo assim, o objetivo deste trabalho foi acompanhar o ciclo ovariano de 13 fêmeas dominantes e subordinadas de S. xanthosternos (n=8) e S. robustus (n=5) por meio de cortes ultrassonográficos sagitais e transversais do útero e dos ovários. Estas fêmeas foram examinadas uma vez por semana durante dois meses. A fase do ciclo ovariano/anestro foi confirmada pela colpocitologia. Os resultados da pesquisa demonstrou diferença significativa (P<0,05) relacionada ao diâmetro crânio-caudal, diâmetro dorso-ventral e diâmetro transversal entre as fêmeas subordinadas em anestro com todas as outras fases do ciclo ovariano e classes sociais. A média do volume uterino foi maior nas fêmeas dominantes que nas subordinadas em todas as fases do ciclo (P<0,05) a exceção da fase folicular. A largura endometrial, durante o período de anestro, foi menor nas fêmeas subordinadas quando comparada às dominantes (P<0,05). Nas fêmeas subordinadas, houve diferenças (P<0,05) nas mensurações endometriais entre o período de anestro e das fases folicular e lútea. Quanto aos ovários, as médias das medidas observadas nas fêmeas dominantes foram superiores as das subordinadas durante o anestro (P<0,05). As médias das medidas das variáveis ovarianas das fêmeas subordinadas apresentaram diferenças entre o anestro e as fases folicular e lútea (P<0,05). Nas fêmeas dominantes o volume do ovário direito foi maior que o do ovário esquerdo durante o anestro e na fase folicular (P<0,05). Folículos e corpos lúteos foram diferenciados pela ultrassonografia na maioria das coletas (86,11%). Durante o anestro não foram observadas estruturas ovarianas mensuráveis nos ovários em ambas as classes sociais. Concluiu-se que a metodologia empregada neste estudo permitiu o acompanhamento do ciclo ovariano das fêmeas S. xanthosternos e S. robustus e que as fases do ciclo/anestro e a classe social das fêmeas influenciaram as medidas do útero e ovários.(AU)

Changes induced by pathogens and metabolic stress on endometrial function in cattle: possible impacts of increased inflammation on fertility / Mudanças induzidas por patógenos e estresse metabólico na função endometrial de bovinos: possíveis impactos do aumento da inflamação na fertilidade

Harmonized embryo maternal relationships, are necessary at the beginning of pregnancy to insure the development of the young embryo and of the placenta. Specific mechanisms modulate the immune balance towards immune-tolerance for the embryo to be accepted by the endometrium. By the same time this tissue is submitted to intense remodelling, under complex signalling, allowing implantation. Some pathogens and metabolic stress, especially excessive mobilisation of fat tissue, disturb this delicate balance. This review describes how these stressors can alter endometrial function through pro-inflammatory mechanisms and by inducing changes of specific signals possibly altering the establishment of contacts and functional interactions between the embryo and the endometrium around time of implantation.(AU)

Changes induced by pathogens and metabolic stress on endometrial function in cattle: possible impacts of increased inflammation on fertility / Mudanças induzidas por patógenos e estresse metabólico na função endometrial de bovinos: possíveis impactos do aumento da inflamação na fertilidade

Harmonized embryo maternal relationships, are necessary at the beginning of pregnancy to insure the development of the young embryo and of the placenta. Specific mechanisms modulate the immune balance towards immune-tolerance for the embryo to be accepted by the endometrium. By the same time this tissue is submitted to intense remodelling, under complex signalling, allowing implantation. Some pathogens and metabolic stress, especially excessive mobilisation of fat tissue, disturb this delicate balance. This review describes how these stressors can alter endometrial function through pro-inflammatory mechanisms and by inducing changes of specific signals possibly altering the establishment of contacts and functional interactions between the embryo and the endometrium around time of implantation.

Reproductive cycles in white Karaman ewes: comparison of ovarian hormone secretion and reproductive behavior in non-pregnant and pregnant ewes in semi-intensive conditions / Ciclo reprodutivo de ovelhas brancas Karaman: comparação da secreção de hormônio ovariano e do comportamento reprodutivo de ovelhas não gestantes e gestantes em condições semi-intensivo

The objective of this study was to characterize the reproductive cycle both endocrinologically and behaviorally in ewes. Blood samples were analyzed by EIA for progesterone (P4), and RIA for estradiol in order to determine the breeding strategy of non-pregnant (n = 11) and pregnant (n = 9) White Karaman throughout the year in the Middle Anatolia (39.570N, 32.530W), Turkey. Estrous cycle lengths and estrous lengths were 18.36 ( 1.03 days and 35.16 ( 5.95 hours, respectively. The breeding season durations were 283 ( 63.36 days and 229.64 ( 63.74 days according to hormonal and behavioral data respectively (p ( 0.01). The highest and lowest data of estrous occurrence frequency was observed in October and June-July, respectively. P4 levels ranged from 0.01 to 9.0 ng mL-1 throughout the year and from 0.01 to 0.16 ng mL-1 during anestrous. Mean plasma estradiol levels were 8.42 ( 2.51 pg mL-1 during the estrous cycle. Postpartum anestrous durations were 134.8 ( 18.5 and 120.78 ( 29.89 days (n = 9) according to behavioral observation and hormonal data, respectively. P4 concentration for the months 1 - 5 of the gestation period ranged from 4.54 to 15.08 ng mL-1. P4 concentrations in 4th and 5th months of gestation were higher than the other months (p ( 0.01). White Karaman reproductive activity is characterized by an extended breeding season and their relatively insensitivity to photoperiod stimulation allows for efficient out of season lamb production.(AU)

O objetivo deste estudo foi caracterizar o ciclo reprodutivo, endocrinológico e o comportamento de ovelhas Karaman. Análises de sangue foram analisadas pelo EIA para progesterona (P4) e RIA para estradiol para determinar as estratégias de reprodução do Karaman Branca de não gestantes (n = 11) e de gestantes (n = 9) durante o todo o ano, em Anatólia, Turkia. O Ciclo estral e a duração do estro foram 18.36 ( 1.03 dias e 35.16 ( 5.95 horas, respectivamente. As durações da época de reprodução foram de 283 ( 63.36 e 229.64 ( 63.74 dias de acordo com os dados hormonais e comportamentais, respectivamente (p ( 0.01). Os maiores e menores dados de frequência do estro ocorreram em outubro e junho-julho, respectivamente. Os níveis de P4 variaram de 0.01 para 9.0 ng ML-1 ao longo do ano e 0.01 - 0.16 ng mL-1 durante o cio. Níveis médios do plasma de estradiol foram 8.42 ( 2.51 pg mL-1 durante o ciclo estral. As durações do pós-parto foram de 134.8 ( 18.5 dias e 120.78 ( 29.89 dias (n = 9) de acordo com a observação do comportamento e os dados hormonais, respectivamente. Concentrações de P4 durante os meses 1 até o 5 do período de gestação variou de 4.54 para 15.08 ng mL-1. Concentrações de P4 no quarto e quinto mês de gestação foram maiores do que nos outros meses (p < 0.01). A atividade reprodutiva do White Karaman é caracterizada por um período de reprodução estendido e relativa insensibilidade à estimulação do fotoperíodo permite a produção eficiente de cordeiros fora de época.(AU)

Reproductive cycles in white Karaman ewes: comparison of ovarian hormone secretion and reproductive behavior in non-pregnant and pregnant ewes in semi-intensive conditions / Ciclo reprodutivo de ovelhas brancas Karaman: comparação da secreção de hormônio ovariano e do comportamento reprodutivo de ovelhas não gestantes e gestantes em condições semi-intensivo

The objective of this study was to characterize the reproductive cycle both endocrinologically and behaviorally in ewes. Blood samples were analyzed by EIA for progesterone (P4), and RIA for estradiol in order to determine the breeding strategy of non-pregnant (n = 11) and pregnant (n = 9) White Karaman throughout the year in the Middle Anatolia (39.570N, 32.530W), Turkey. Estrous cycle lengths and estrous lengths were 18.36 ( 1.03 days and 35.16 ( 5.95 hours, respectively. The breeding season durations were 283 ( 63.36 days and 229.64 ( 63.74 days according to hormonal and behavioral data respectively (p ( 0.01). The highest and lowest data of estrous occurrence frequency was observed in October and June-July, respectively. P4 levels ranged from 0.01 to 9.0 ng mL-1 throughout the year and from 0.01 to 0.16 ng mL-1 during anestrous. Mean plasma estradiol levels were 8.42 ( 2.51 pg mL-1 during the estrous cycle. Postpartum anestrous durations were 134.8 ( 18.5 and 120.78 ( 29.89 days (n = 9) according to behavioral observation and hormonal data, respectively. P4 concentration for the months 1 - 5 of the gestation period ranged from 4.54 to 15.08 ng mL-1. P4 concentrations in 4th and 5th months of gestation were higher than the other months (p ( 0.01). White Karaman reproductive activity is characterized by an extended breeding season and their relatively insensitivity to photoperiod stimulation allows for efficient out of season lamb production.

O objetivo deste estudo foi caracterizar o ciclo reprodutivo, endocrinológico e o comportamento de ovelhas Karaman. Análises de sangue foram analisadas pelo EIA para progesterona (P4) e RIA para estradiol para determinar as estratégias de reprodução do Karaman Branca de não gestantes (n = 11) e de gestantes (n = 9) durante o todo o ano, em Anatólia, Turkia. O Ciclo estral e a duração do estro foram 18.36 ( 1.03 dias e 35.16 ( 5.95 horas, respectivamente. As durações da época de reprodução foram de 283 ( 63.36 e 229.64 ( 63.74 dias de acordo com os dados hormonais e comportamentais, respectivamente (p ( 0.01). Os maiores e menores dados de frequência do estro ocorreram em outubro e junho-julho, respectivamente. Os níveis de P4 variaram de 0.01 para 9.0 ng ML-1 ao longo do ano e 0.01 - 0.16 ng mL-1 durante o cio. Níveis médios do plasma de estradiol foram 8.42 ( 2.51 pg mL-1 durante o ciclo estral. As durações do pós-parto foram de 134.8 ( 18.5 dias e 120.78 ( 29.89 dias (n = 9) de acordo com a observação do comportamento e os dados hormonais, respectivamente. Concentrações de P4 durante os meses 1 até o 5 do período de gestação variou de 4.54 para 15.08 ng mL-1. Concentrações de P4 no quarto e quinto mês de gestação foram maiores do que nos outros meses (p < 0.01). A atividade reprodutiva do White Karaman é caracterizada por um período de reprodução estendido e relativa insensibilidade à estimulação do fotoperíodo permite a produção eficiente de cordeiros fora de época.

Intrinsic and extrinsic factors that influence ovarian environment and efficiency of reproduction in cattle

The emergent concepts on ovary environment,reproductive physiology and the development ofpharmacology are constantly supporting the advance ofassisted reproduction. Within the last years, thebiotechnics related to the synchronization of folliculardevelopment and the manipulation of bovine estruscycle have progressed rapidly and consistently. Thecombined use of timed-artificial insemination (TAI),superovulation (SOV), ovum pick up (OPU), in vitroembryo production (IVEP) and timed-embryo transfer(TET) has a great potential to improve reproductiveoutcomes and disseminate selected genetics,diminishing the interval of generations and improvingherds genetic gain. However, several factors canpotentially affect the efficiency of these procedures. Theknowledge of the particularities of the genetic groups,follicular growth manipulation, follicular populationpredictors, and metabolic and environmental aspectsthat interfere with ovarian environment and,consequently, oocyte quantity and quality is crucial tooptimize the reproductive programs. This review aimsto elucidate some factors that affect the ovarianenvironment and must be well known in order toimprove the efficiency of reproduction in cattle.

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)

Consequences of eight consecutive applications of equine chorionic gonadotropin on ovarian follicle development and ovulation in bos indicus cows / Consequências do uso consecutivo de oito doses de gonadotrofina coriônica equina no desenvolvimento folicular e ovulação de vacas bos indicus

The equine chorionic gonadotropin (eCG) is a glycoprotein produced in mare endometrial calices. In bovine, it is used in estrus synchronization protocols. However, studies have shown that it is potentially immunogenic and its effect can decrease after repetitive use. This study aimed to evaluate antral follicle dynamics, corpus luteum (CL) and ovulation rate in bos indicus cows submitted to an estrus synchronization protocol in association with eCG for eight times consecutively. Ten cyclical, multiparous, and pasture raised beef cows were divided into two groups: control group (n=5) and eCG group (n=5). In 30 day interval, all animals were synchronized with the same estrogen/progesterone based protocol, totalizing 8 re-synchronizations. Cows in the treatment group received 300IU eCG 48 hours prior to the presumable ovulation. Ultrassound examinations were performed on Day 4 of the protocol (approximately 1.5 days after follicle recruitment) to count antral follicles, on Day 10, to count antral follicles and to measure size of the largest follicle and on Day 18 to measure the diameter of the CL. No difference (P>0.05) between follicular growth and size of the pre-ovulatory follicle was reported between groups. Cows treated with eCG had a larger (P<0.05) CL and increased (P<0.05) ovulation rate (18mm and 92%, respectively) when compared with control group (14.1mm and 80%, respectively). Furthermore, consecutive treatments did not affect CL nor ovulation rates. In conclusion, eCG treatment increased CL size and ovulation rate even after 8 consecutive treatments.(AU)

A gonadotrofina coriónica equina (ECG) é uma glicoproteína produzida nos cálices endometriais da égua. Em bovinos, é utilizada em protocolos de sincronização do estro. Estudos têm mostrado que ela é potencialmente imunogênica e seu efeito pode diminuir depois de utilização repetida. O objetivo do presente trabalho foi avaliar a dinâmica folicular, o diâmetro do corpo lúteo (CL) e taxa de ovulação em vacas bos indicus submetidas a um protocolo de sincronização estral com eCG por oito vezes. Dez vacas de corte, cíclicas, multíparas e solteiras foram divididas em dois grupos: grupo controle (n=5) e grupo eCG (n=5). Em um intervalo de 30 dias, os animais foram sincronizados com um protocolo de estrógeno/progesterona, totalizando 8 re-sincronizações. Os animais do grupo tratamento receberam 300UI eCG 48 horas antes da provável ovulação. Exames ultrasonográficos foram realizados no dia 4 do protocolo (aproximadamente 1,5 dias após o recrutamento folícular), para contar folículos antrais, no dia 10, contar folículos antrais e medir o tamanho do maior folículo e, no dia 18, para medir o diâmetro do CL. Não foi encontrada diferença (P>0,05) entre folículos no dia 4 ou 10. Vacas tratadas com eCG tinham um maior (P<0.05) CL e elevada (P<0.05) taxa de ovulação (18mm e 92%, respectivamente) quando comparadas ao grupo controle (14,1mm e 80%, respectivamente). Além disso, tratamentos consecutivos não afetaram o CL nem as taxas de ovulação. Em conclusão, o tratamento com eCG aumentou o tamanho do CL e taxa de ovulação, mesmo depois de 8 tratamentos consecutivos.(AU)

Administration of GnRH on the day of fixed-time artificial insemination (FTAI) and melengestrol acetate (MGA) administration after ftai in non-suckling nelore cattle / Aplicação de GnRH no dia da inseminação artificial em tempo fixo (IATF) e administração de acetato de melengestrol (MGA) após iatf em vacas nelore solteiras

The present study evaluated the effect of administering buserelin acetate (GnRH) at the time of fixed-time artificial insemination (FTAI), along with the effect of oral administration of melengestrol acetate (MGA) after FTAI on conception rates in non-suckling Nelore cattle. In Experiment I, the effect of GnRH application at the time of FTAI was evaluated, as was administration of MGA from the 13th through the 18th day following FTAI (D24 to D29 after the initiation of the FTAI protocol). Experiment I was performed in 215 non-suckling cattle of the Nelore breed, divided into four experimental groups: Control group: 56 cows subjected to FTAI without GnRH injection; GnRH group: 51 cows subjected to GnRH at the time of FTAI; MGA Group: 57 cows subjected to FTAI without the application of GnRH with mineral supplementation and the addition of 2.28 g of MGA® Premix per cow per day from D24 to D29 after the initiation of the FTAI protocol; MGA and GnRH group: 51 cows subjected to GnRH injection at the time of FTAI, with mineral supplementation and the addition of 2.28 g of MGA® Premix per cow per day from D24 to D29 after the initiation of the FTAI protocol. In Experiment II, the effect of providing MGA five to ten days after FTAI was evaluated in 196 non-suckling pluriparous Nelore cows, divided into two groups: Control group: 104 cows subjected to FTAI, not supplemented with MGA; treated group: 92 cows supplemented with the addition of 2.28 g of MGA® Premix per cow per day from D15 to D20 after the initiation of the FTAI protocol. Diagnosis of gestation was carried out 45 days after FTAI. Both experiments were conducted using a completely randomised design and analysed via the SAS MIXED procedure.[...](AU)

Avaliou-se o efeito da aplicação de Acetato de Buserelina (GnRH) no momento da IATF e o efeito do fornecimento, via oral, de Acetato de Melengestrol (MGA) após IATF, sobre a taxa de concepção em vacas solteiras da raça Nelore. No Experimento I, avaliou-se o efeito da aplicação de GnRH no momento da IATF e do fornecimento de MGA do décimo terceiro ao décimo oitavo dia após a IATF (D24 ao D29 após o início do protocolo de IATF), em 215 vacas solteiras da raça Nelore divididas em quatro grupos experimentais; grupo Controle: 56 vacas submetidas à IATF sem aplicação de GnRH; Grupo GnRH: 51 vacas submetidas à aplicação de GnRH no ato da IATF; Grupo MGA: 57 vacas submetidas à IATF sem aplicação de GnRH e suplementação mineral, com adição de 2,28g de MGA® Premix/vaca/dia do D24 ao D29 após o início do protocolo de IATF; Grupo MGA e GnRH: 51 vacas submetidas à aplicação de GnRH no momento da IATF e suplementação mineral com adição de 2,28g MGA® Premix/vaca/dia do D24 ao D29 após o início do protocolo de IATF. No Experimento II, avaliou-se o efeito do fornecimento de MGA cinco a dez dias após a IATF em 196 vacas pluríparas solteiras da raça Nelore, divididas em dois grupos experimentais; grupo Controle: 104 vacas submetidas à IATF sem fornecimento de MGA, e grupo Tratado: 92 vacas suplementadas, com adição de 2,28g de MGA® Premix/vaca/dia do D15 ao D20 após o início do protocolo de IATF. Realizou-se diagnóstico de gestação 45 dias após a IATF. Ambos os Experimentos foram conduzidos em delineamento inteiramente casualizado, analisados através do procedimento MIXED do SAS. No Experimento I, o grupo controle obteve menor taxa de concepção (32,1%) comparado com os demais grupos avaliados quando fornecido MGA após a IATF (45,6%), GnRH no momento da IATF (50,9%), bem como a associação dos dois tratamentos (50,9%) (P<0,05). No experimento II, o grupo controle obteve maior taxa de concepção (40,38%) quando comparado com o grupo que recebeu MGA pós-IATF (18,48%) (P<0,05).[...](AU)

Managing gestion in cattle

Once a cow becomes pregnant, the effect of pregnancy toss on its reproductive cycle is a topic of great interest for dairu herds. This paper reviews the factors of a non-infectious nature that effect the pregnancy maintenance during the late embryonic/early fetal period. Some clinical suggestion on bovne neosporosis and coxiellosis are also highlighte.

Managing gestion in cattle

Once a cow becomes pregnant, the effect of pregnancy toss on its reproductive cycle is a topic of great interest for dairu herds. This paper reviews the factors of a non-infectious nature that effect the pregnancy maintenance during the late embryonic/early fetal period. Some clinical suggestion on bovne neosporosis and coxiellosis are also highlighte.(AU)

Efeito do soro de cadela em estro na maturação in vitro de ovócitos caninos / Effect of estrus bitch serum on in vitro maturation of canine oocyte

Avaliou-se o efeito do soro de cadela em estro na maturação in vitro de ovócitos caninos, utilizando-se 92 ovócitos de cadelas, submetidas à cirurgia eletiva de ovarioisterectomia. Os ovócitos foram selecionados e distribuídos em dois tratamentos: T1 (n = 48), ovócitos cultivados in vitro durante 96 horas utilizando meio base - TCM199 + 5µg/mL de LH + 20µg/mL de FSH - mais 10 por cento de soro inativado de vaca em estro e T2 (n = 44), ovócitos cultivados em meio base mais 10 por cento de soro inativado de cadela em estro. O percentual de ovócitos observados em metáfase I não indicou diferenças (P>0,05) entre T1 (2,1 por cento) e T2 (0,0 por cento), porém a taxa de ovócitos maduros (metáfase II) foi diferente (P<0,05), sendo 27,1 por cento em T1 e 47,7 por cento em T2. O mesmo fato ocorreu com a taxa de cromatina condensada (P<0,01), com 14,6 e 0,0 por cento, respectivamente. Nos ovócitos sem configuração cromossômica, não foram observadas diferenças (P>0,05), sendo 56,3 por cento em T1 e 52,3 por cento em T2. Estes resultados indicam que a adição de soro de cadela em estro no meio de cultivo oferece melhores condições para o desenvolvimento in vitro, quando comparado à de soro de vaca em estro.(AU)

This study aimed to evaluate the effect of estrus on in vitro canine oocyte. A total of 92 oocyte from bitches under ovary-hysterectomy surgery was used. The oocytes were selected and randomly assigned to two different treatments, being T1 (n = 48) in vitro cultured for 96h using basic medium (TCM199 + 5µg/mL of LH + 20µg/mL of FSH), plus 10 percent of cow inactive serum in estrus and T2 (n = 44) basic medium plus 10 percent of bitch inactive serum in estrus. The percentage of oocyte observed on metaphase I do not indicate a difference (P>0.05) between T1 (2.1 percent) and T2 (0.0 percent). However, the rate of mature oocyte (metaphase II) was different (P<0.05), being 27.1 percent for T1 and 47.7 percent for T2. There was difference (P<0.05) in the condensed chromatin rate for T1 (14.6 percent) and T2 (0.0 percent), respectively. There was no difference (P>0.05) between T1 (56.3 percent) and T2 (52.3 percent) in oocyte with no chromosome configuration. These results indicate that supplementation with estrus bitch serum on culture media offer better conditions to in vitro development, when compared to estrus cow serum.(AU)

Ovarian development and spawning of Serra Spanish mackerel in coastal waters of Northeastern Brazil / Desenvolvimento ovariano e desova da Serra nas águas costeiras do nordeste do Brasil

The Serra Spanish mackerel, Scomberomorus brasiliensis is an important fishery resource of the Atlantic Ocean and is a major component of artisanal fisheries in northern and northeastern Brazil. Ovarian development and spawning period of S. brasiliensis were investigated using both macroscopic and histological techniques. Mean monthly values of GSI and ovarian maturation indicate that the main spawning period occurs during the rainy season.(AU)

A Serra, Scomberomorus brasiliensis, é uma espécie marinha de valor comercial do oceano Atlântico sendo um maior componente de pesca artesanal no norte e nordeste brasileiros. Desenvolvimento ovariano e época de desova de S. brasiliensis foram investigados utilizando-se técnicas macroscópicas e histológicas. Valores mensais médios de IGS e maturação gonadal indicam que a época de desova ocorre durante o período de chuva.(AU)

Controle local e endócrino do desenvolvimento e da regressão do corpo lúteo bovino / Endocrine and local control of growth and regression of bovine corpus luteum

O corpo lúteo é uma glândula endócrina, ovariana e transitória, formada a partir do folículo ovulado, cujo principal produto secretado é a progesterona, essencial para o estabelecimento e a manutenção da prenhez e para a ciclicidade ovariana. Dessa forma, o conhecimento aprofundado da fisiologia luteínica, além de seu valor intrínseco como conhecimento básico, pode também contribuir para a reprodução animal em seu aspecto aplicado. Este artigo revisa os principais mecanismos reguladores do desenvolvimento e da regressão do corpo lúteo, incluindo agentes endócrinos e reguladores locais como fatores de crescimento, peptídeos vasoativos, esteróides e prostaglandinas.(AU)

The corpus luteum is a transitory, endocrine ovarian gland, formed following ovulation, which secrets progesterone, an essential hormone for pregnancy establishment and maintenance as well as ovarian cyclicity. Therefore, a more complete understanding of the luteal physiology, apart from its intrinsic value as basic knowledge, may also contribute within the applied aspect of animal reproduction. This article reviews the principal mechanisms that regulate luteal development and regression, including endocrine agents and local regulators such as growth factors, vasoative peptides, steroids and prostaglandins.(AU)

Controle local e endócrino do desenvolvimento e da regressão do corpo lúteo bovino / Endocrine and local control of growth and regression of bovine corpus luteum

O corpo lúteo é uma glândula endócrina, ovariana e transitória, formada a partir do folículo ovulado, cujo principal produto secretado é a progesterona, essencial para o estabelecimento e a manutenção da prenhez e para a ciclicidade ovariana. Dessa forma, o conhecimento aprofundado da fisiologia luteínica, além de seu valor intrínseco como conhecimento básico, pode também contribuir para a reprodução animal em seu aspecto aplicado. Este artigo revisa os principais mecanismos reguladores do desenvolvimento e da regressão do corpo lúteo, incluindo agentes endócrinos e reguladores locais como fatores de crescimento, peptídeos vasoativos, esteróides e prostaglandinas.

The corpus luteum is a transitory, endocrine ovarian gland, formed following ovulation, which secrets progesterone, an essential hormone for pregnancy establishment and maintenance as well as ovarian cyclicity. Therefore, a more complete understanding of the luteal physiology, apart from its intrinsic value as basic knowledge, may also contribute within the applied aspect of animal reproduction. This article reviews the principal mechanisms that regulate luteal development and regression, including endocrine agents and local regulators such as growth factors, vasoative peptides, steroids and prostaglandins.

Human antral folliculogenesis: what we have learned from the bovine and equine models

The study of ovarian folliculogenesis has been of great interest to scientists and clinicians in the human and veterinary health fields for more than 20 centuries. Initial studies of the ovarian follicle were based on anatomical descriptions post-mortem, followed by histologic and endocrinologic evaluation of ovarian status. The introduction of high resolution ultrasonography in the 1980s provided a long-awaited tool to image the reproductive tissues in situ in both animal and human species. The bovine and equine species have been established as models for the study of human ovarian folliculogenesis. Profound similarities in the dynamics of follicle development exist between the menstrual cycle in humans and the estrous cycle in cattle and horses. Disparities between species appear specific rather than general. Research performed in women thus far has led to the concepts that: 1) follicle development occurs in a wave-like manner during the menstrual cycle, 2) the number of waves per cycle correlates positively with the length of the cycle, 3) the emergence of follicle waves in women are preceded by a rise in circulating FSH, 4) selection of a dominant follicle may occur in each wave of the cycle, and 5) a decline in circulating FSH and increase in follicular estradiol, inhibin A, and IGF-II act collectively to enable the dominant follicle to continue to grow in an endocrine environment of decreasing FSH and increasing LH, while subordinate follicles undergo regression. The goal of continued research using animal models for studying human ovarian function is to provide the hypothetical basis for further studies in women, which will ultimately lead to the development of safer and more efficacious infertility and contraceptive therapies.

Human antral folliculogenesis: what we have learned from the bovine and equine models

The study of ovarian folliculogenesis has been of great interest to scientists and clinicians in the human and veterinary health fields for more than 20 centuries. Initial studies of the ovarian follicle were based on anatomical descriptions post-mortem, followed by histologic and endocrinologic evaluation of ovarian status. The introduction of high resolution ultrasonography in the 1980s provided a long-awaited tool to image the reproductive tissues in situ in both animal and human species. The bovine and equine species have been established as models for the study of human ovarian folliculogenesis. Profound similarities in the dynamics of follicle development exist between the menstrual cycle in humans and the estrous cycle in cattle and horses. Disparities between species appear specific rather than general. Research performed in women thus far has led to the concepts that: 1) follicle development occurs in a wave-like manner during the menstrual cycle, 2) the number of waves per cycle correlates positively with the length of the cycle, 3) the emergence of follicle waves in women are preceded by a rise in circulating FSH, 4) selection of a dominant follicle may occur in each wave of the cycle, and 5) a decline in circulating FSH and increase in follicular estradiol, inhibin A, and IGF-II act collectively to enable the dominant follicle to continue to grow in an endocrine environment of decreasing FSH and increasing LH, while subordinate follicles undergo regression. The goal of continued research using animal models for studying human ovarian function is to provide the hypothetical basis for further studies in women, which will ultimately lead to the development of safer and more efficacious infertility and contraceptive therapies.(AU)

Temperature gradients in female reproductive tissues and their potential significance

This review challenges the long-standing dogma that deep-body temperature should be regarded as uniform. Not only may this not be so, but small gradients in temperature in and across reproductive tissues might have assumed functional importance during the evolution of eutherian mammals. Temperature gradients within the Fallopian tubes of estrous animals are interpreted in a context of preovulatory storage of viable spermatozoa and their periovulatory activation and release from the functional reservoir in the caudal isthmus. Proposals concerning the response of potentially-fertilizing spermatozoa to increasing temperature along the isthmus of the Fallopian tube are recalled, and application of the term thermotaxis to this phase of sperm migration is assessed critically. Classical findings on the temperature of Graafian follicles in rabbits and women are highlighted, and more recent work on temperatures in pig preovulatory follicles is considered in detail. Although an experimental approach involving anaesthesia and infrared sensing is open to criticism, the finding that preovulatory follicles are cooler than ovarian stroma cannot be discounted as artifact. Instead, evidence for endothermic reactions that act to lower temperature within pre-ovulatory follicles is presented together with a description of relevant counter-current vascular physiology that enables maintenance of a cooler follicular temperature. As to future experimental work, the possibility is raised that temperatures may not be uniform across the cytoplasm of maturing oocytes nor at different stages of the cell cycle in very young embryos. These proposals lead to speculation that temperature may be exploited at a molecular level to modulate unfolding gene expression in zygotes and early cleavage stage embryos. Modern micro-imaging technology needs to be applied to such concepts.