Reproduction in South American wild canids-A review.

Canids occupy the top of the food chain and are fundamental in sustaining a wild animal/environmental balance. South America, the most biodiverse continent, has 11 species of canids inhabiting diverse biomes, with or without overlapping territories. Although several species are threatened, little is known about their reproductive biology. Remarkably, basic knowledge regarding ejaculate characteristics, sexual behavior, female reproductive cycles, pregnancy and management, and parturition are scarce or absent. These gaps complicate or preclude development of conservation programs. This review compiles the current knowledge of the reproductive biology of South American canids and discusses implications of this scenario.

Dynamics of the Reproductive Changes and Acquisition of Oocyte Competence in Nelore (Bos taurus indicus) Calves during the Early and Intermediate Prepubertal Periods

The purpose of this study was to characterize the reproductive physiology, oocyte competence, and chromatin compaction in Nelore calves in the early-prepubertal period (EPP) and the intermediate-prepubertal period (IPP). Calves aged 2-5 (EPP) and 8-11 months old (IPP) were assigned to Trial 1 (morpho-physiological-endocrine evaluations, n = 8) or Trial 2 (oocyte donors, n = 8) vs. the respective control groups of cows (n = 8, each). All morphological endpoints, except the antral follicle count, increased from the EPP to the IPP. The EPP LH-FSH plasma concentrations were similar to cows, whereas LH was lower and FSH was higher in the IPP than in cows. . Cows produced more Grade I (12.9% vs. 4.1% and 1.7%) and fewer Grade III COC (30.1% vs. 44.5% and 49.0%) than the EPP and IPP calves, respectively. The IPP calves' oocyte diameter was similar to those from cows but greater than those from EPP females (124.8 ± 8.5 and 126.0 ± 7.5 µm vs. 121.3 ± 7.5 µm, respectively). The expression of the chromatin compaction-related gene HDAC3 was downregulated in calves. The proportion of the blastocyst rate to the controls was lower in EPP than in IPP calves (43.7% vs. 78.7%, respectively). Progressive oocyte competence was found during the prepubertal period, which can help to decide whether to recover oocytes from calves.

Effect of seasonally changing aerial environment on testosterone in Karagouniko and Chios sheep

A well-established activity in Greece and other Mediterranean countries is sheep farming. Karagouniko and Chios sheep are promising breeds and targets for the reproductive physiologist's attention. Under this context, part of the reproductive physiology of Karagouniko and Chios was investigated, taking into account the environment. Specifically, four time periods were considered; April-June (Long days, increasing photoperiod length), July-September (Long days, decreasing photoperiod length), October-December (Short days, decreasing photoperiod length), and January-March (Short days, increasing photoperiod length). The effect of the period on the concentration of the testosterone (main male hormone) in rams of the breeds above was studied, by using repeated measures analysis of variance, also taking into account the environmental variables air temperature, relative humidity, sunshine, rainfall, and photoperiod, in the Artificial Insemination Center of Karditsa (39°21'18''N, 21°54'19''E), Greece. The lowering of photoperiod from April-June to July-September (long days) and afterward, even more to October-December (short days) coincided with a progressive increase of testosterone in both breeds. Photoperiod seems to have a major role in the concentration of Karagouniko and Chios breeds' testosterone compared to the other environmental variables. When considering the whole experimental period, Chios sheep had significantly higher (P < 0.05) testosterone (1.95 ng/ml) than the Karagouniko one (1.55 ng/ml). Our findings could contribute towards the more rational exploitation of the examined sheep breeds.(AU)

Effect of seasonally changing aerial environment on testosterone in Karagouniko and Chios sheep

A well-established activity in Greece and other Mediterranean countries is sheep farming. Karagouniko and Chios sheep are promising breeds and targets for the reproductive physiologist's attention. Under this context, part of the reproductive physiology of Karagouniko and Chios was investigated, taking into account the environment. Specifically, four time periods were considered; April-June (Long days, increasing photoperiod length), July-September (Long days, decreasing photoperiod length), October-December (Short days, decreasing photoperiod length), and January-March (Short days, increasing photoperiod length). The effect of the period on the concentration of the testosterone (main male hormone) in rams of the breeds above was studied, by using repeated measures analysis of variance, also taking into account the environmental variables air temperature, relative humidity, sunshine, rainfall, and photoperiod, in the Artificial Insemination Center of Karditsa (39°21’18’’N, 21054’19’’E), Greece. The lowering of photoperiod from April-June to July-September (long days) and afterward, even more to October-December (short days) coincided with a progressive increase of testosterone in both breeds. Photoperiod seems to have a major role in the concentration of Karagouniko and Chios breeds' testosterone compared to the other environmental variables. When considering the whole experimental period, Chios sheep had significantly higher (P < 0.05) testosterone (1.95 ng/ml) than the Karagouniko one (1.55 ng/ml). Our findings could contribute towards the more rational exploitation of the examined sheep breeds.

Understanding how environmental factors influence reproductive aspects of wild myomorphic and hystricomorphic rodents.

Myomorphic and hystricomorphic rodents are vital for maintaining various ecosystems around the planet. This review enables a better understanding of how these rodents respond to environmental factors and adapt to climate adversities. Innumerable factors, such as photoperiod, rainfall, and temperature, can impair or contribute to the quality of rodent reproductive parameters. Prolonged animal exposure to high ambient temperatures alters thermoregulation mechanisms and causes testicular and ovarian tissue degeneration and hormonal deregulation. Photoperiod influences the biological circannual rhythm and reproductive cycles of rodents because it strongly regulates melatonin secretion by the pineal gland, which modulates gonadotropic hormone secretion. Rainfall quantity directly regulates the abundance of fruits in an ecosystem, which modulates the reproductive seasonality of species which are most dependent on a seasonal fruit-based diet. Species with a more diversified fruit diet have smaller reproductive seasonality. As such, habitats are chosen by animals for various reasons, including the availability of food, sexual partners, intra-and inter-specific competition, and predation. This knowledge allows us to monitor and establish management plans to aid in conservation strategies for wild rodent species.

Understanding how environmental factors influence reproductive aspects of wild myomorphic and hystricomorphic rodents

Abstract Myomorphic and hystricomorphic rodents are vital for maintaining various ecosystems around the planet. This review enables a better understanding of how these rodents respond to environmental factors and adapt to climate adversities. Innumerable factors, such as photoperiod, rainfall, and temperature, can impair or contribute to the quality of rodent reproductive parameters. Prolonged animal exposure to high ambient temperatures alters thermoregulation mechanisms and causes testicular and ovarian tissue degeneration and hormonal deregulation. Photoperiod influences the biological circannual rhythm and reproductive cycles of rodents because it strongly regulates melatonin secretion by the pineal gland, which modulates gonadotropic hormone secretion. Rainfall quantity directly regulates the abundance of fruits in an ecosystem, which modulates the reproductive seasonality of species which are most dependent on a seasonal fruit-based diet. Species with a more diversified fruit diet have smaller reproductive seasonality. As such, habitats are chosen by animals for various reasons, including the availability of food, sexual partners, intra-and inter-specific competition, and predation. This knowledge allows us to monitor and establish management plans to aid in conservation strategies for wild rodent species.

Técnica de inseminação artificial por tração cervical e função luteal em ovelhas Santa Inês após estro sincronizado com cloprostenol ou progestágeno-eCG / Technique of artificial ins emination by cervical traction and luteal function in Santa Inês ewes after synchronized estrus with cloprostenol or progestagen-eCG

Avaliou-se a influência do protocolo de sincronização de estro na execução da técnica de inseminação artificial por tração cervical (ITC) e subsequente perfil sérico de progesterona em ovelhas Santa Inês. Um grupo foi submetido a duas aplicações de cloprostenol com sete dias de intervalo (PGF2α, n=43), outro grupo foi sincronizado com MAP-eCG (P4-eCG, n=40) e ovelhas ao estro natural (EN, n=10) formaram grupo controle. Com as ovelhas contidas em estação, foi realizada a técnica ITC utilizando um aplicador metálico e mandril. Foram avaliadas a profundidade de penetração e intensidade de reação da ovelha ao manejo da técnica. Dosagens de estradiol e progesterona foram feitas antes e depois da ITC/estro natural, respectivamente. Os níveis de estradiol foram superiores com P4-eCG vs PGF2α (P < 0,05), mas não houve influência do protocolo na execução da técnica. Ocorreram 83,5% de deposição intrauterina do sêmen, o tempo médio foi de 32 segundos e 90,7% das ovelhas apresentaram reação fraca ou moderada durante o manejo. Os níveis de progesterona foram semelhantes entre ITC e estro natural. Independente do protocolo hormonal, a técnica ITC em ovelhas Santa Inês mantidas em estação mostrou-se viável no tempo de penetração da cérvice e deposição intrauterina do sêmen, não comprometendo a função luteal subsequente.

The influence of estrus synchronization protocol was evaluated on the artificial insemination technique by cervical traction (ICT) and subsequent progesterone serum profile in Santa Inês ewes. One group was submitted to two applications of cloprostenol seven days apart (PGF2α, n=43), another group was synchronized with MAP-eCG (P4-eCG, n=40) and ewes at natural estrus (NE, n=10) formed a control group. With the ewe contained in the stand position, the ICT technique was performed using a metal applicator and mandrel. Depth of penetration and reaction intensity of the ewe to the handling of the technique were evaluated. Dosages of estradiol and progesterone were performed before and after ICT / natural estrus, respectively. Estradiol levels were higher with P4-eCG vs PGF2α

Técnica de inseminação artificial por tração cervical e função luteal em ovelhas Santa Inês após estro sincronizado com cloprostenol ou progestágeno-eCG / Technique of artificial ins emination by cervical traction and luteal function in Santa Inês ewes after synchronized estrus with cloprostenol or progestagen-eCG

Avaliou-se a influência do protocolo de sincronização de estro na execução da técnica de inseminação artificial por tração cervical (ITC) e subsequente perfil sérico de progesterona em ovelhas Santa Inês. Um grupo foi submetido a duas aplicações de cloprostenol com sete dias de intervalo (PGF2α, n=43), outro grupo foi sincronizado com MAP-eCG (P4-eCG, n=40) e ovelhas ao estro natural (EN, n=10) formaram grupo controle. Com as ovelhas contidas em estação, foi realizada a técnica ITC utilizando um aplicador metálico e mandril. Foram avaliadas a profundidade de penetração e intensidade de reação da ovelha ao manejo da técnica. Dosagens de estradiol e progesterona foram feitas antes e depois da ITC/estro natural, respectivamente. Os níveis de estradiol foram superiores com P4-eCG vs PGF2α (P < 0,05), mas não houve influência do protocolo na execução da técnica. Ocorreram 83,5% de deposição intrauterina do sêmen, o tempo médio foi de 32 segundos e 90,7% das ovelhas apresentaram reação fraca ou moderada durante o manejo. Os níveis de progesterona foram semelhantes entre ITC e estro natural. Independente do protocolo hormonal, a técnica ITC em ovelhas Santa Inês mantidas em estação mostrou-se viável no tempo de penetração da cérvice e deposição intrauterina do sêmen, não comprometendo a função luteal subsequente.(AU)

The influence of estrus synchronization protocol was evaluated on the artificial insemination technique by cervical traction (ICT) and subsequent progesterone serum profile in Santa Inês ewes. One group was submitted to two applications of cloprostenol seven days apart (PGF2α, n=43), another group was synchronized with MAP-eCG (P4-eCG, n=40) and ewes at natural estrus (NE, n=10) formed a control group. With the ewe contained in the stand position, the ICT technique was performed using a metal applicator and mandrel. Depth of penetration and reaction intensity of the ewe to the handling of the technique were evaluated. Dosages of estradiol and progesterone were performed before and after ICT / natural estrus, respectively. Estradiol levels were higher with P4-eCG vs PGF2α(AU)

Understanding how environmental factors influence reproductive aspects of wild myomorphic and hystricomorphic rodents

Myomorphic and hystricomorphic rodents are vital for maintaining various ecosystems around the planet. This review enables a better understanding of how these rodents respond to environmental factors and adapt to climate adversities. Innumerable factors, such as photoperiod, rainfall, and temperature, can impair or contribute to the quality of rodent reproductive parameters. Prolonged animal exposure to high ambient temperatures alters thermoregulation mechanisms and causes testicular and ovarian tissue degeneration and hormonal deregulation. Photoperiod influences the biological circannual rhythm and reproductive cycles of rodents because it strongly regulates melatonin secretion by the pineal gland, which modulates gonadotropic hormone secretion. Rainfall quantity directly regulates the abundance of fruits in an ecosystem, which modulates the reproductive seasonality of species which are most dependent on a seasonal fruit-based diet. Species with a more diversified fruit diet have smaller reproductive seasonality. As such, habitats are chosen by animals for various reasons, including the availability of food, sexual partners, intra-and inter-specific competition, and predation. This knowledge allows us to monitor and establish management plans to aid in conservation strategies for wild rodent species.(AU)

Impact of heat stress on the reproductive performance and physiology of ewes: a systematic review and meta-analyses.

High values of ambient temperature and relative humidity negatively affect livestock because they induce heat stress. In heat-stressed ewes, the reproduction is affected, although there apparently is a different effect depending on their physiological status. Therefore, we conducted a systematic review and meta-analyses to estimate the effect of heat stress on the reproductive performance and physiology of cycling or pregnant ewes. We included studies in which pregnant or cycling ewes were exposed to heat stress and included a comparison group. We assessed the risk of bias and used meta-analyses that included the period of exposure to calculate pooled estimates. We included 36 studies comprising 20,626 ewes, and the meta-analyses demonstrated that heat stress decreased 7.09 h (95% CI, - 10.75, - 3.43) the duration of estrus in cycling ewes but increased 0.57 days (95% CI, 0.23, 0.92) the length of the cycle, although differentially affecting the expression of sexual behavior. Heat-stressed cycling ewes had greater odds of embryo mortality (OR = 12.36; 95% CI, 7.10, 21.54) and a decreased chance of impregnation (OR = 0.41; 95% CI, 0.23, 0.75). In heat-stressed pregnant ewes, placental and fetal weights were reduced, respectively in 183.62 g (95%CI, - 252.25, - 114.99) and 1665.18 g (95% CI, - 2136.82, - 1193.55). Heat stress increased ewes' body temperature 1.13 °C (95% CI, 0.85, 1.42) and respiratory rate 93.53 breaths/min (95% CI, 63.5, 123.5) without affecting heart rate. In a sub-group analyses, the period of exposure was shown to cause a significant effect. In conclusion, our results revealed a differential effect of heat stress that depends on both the physiological status of ewes and the period of exposure, and identify susceptible reproductive stages during which the severe effects of heat stress can be prevented/ameliorated.

Endometrial prostaglandin F2α in vitro production and its modulation regarding dominant follicle position in cattle / Produção in vitro de PGF F2α endometrial e sua modulação referente ao folículo dominante em bovinos

Prostaglandin F2α (PGF2α) determines luteolysis in cattle, and the ability to manipulate its endogenous synthesis is indispensible for large-scale animal breeding. Estradiol (E2) and progesterone (P4) modulate several molecular pathways in endometrial cells, including the synthesis of PGF2α; however, its specific mechanisms are still not totally known. This study investigated the production in vitro and possible modulation of endometrial PGF2α due to a local effect of endogenous E2 in the ipsilateral uterine horn (UH) containing the dominant follicle (DF) or from P4 in ipsilateral horn containing the corpus luteum (CL). The PGF2α stimulators oxytocin (OT) and phorbol 12,13-dibutyrate (PDBu) were incubated with endometrial explants, and PGF2α content was measured. For that, cycling cows were synchronized, the development of DF and CL was examined by ultrasonography and on the seventh day of the estrous cycle, endometrial explants were collected and cultured in medium supplemented with 10-6 M PDBu or 10-6 M OT or non-supplemented. Media samples were collected immediately after treatment and 60 min later. Radioimmunoassay showed that the PGF2α content of the UH ipsilateral to the DF was 49% less than that of the contralateral UH (8.22 ± 0.95 vs. 12.24 ± 0.95 pg/mL/mg tissue, respectively; P < 0.01). However, the PGF2α levels did not differ between the UHs as a function of the CL position (9.46 ± 0.95 vs. 11 ± 0.95 pg/mL/mg; P > 0.05). The cellular stimulators promoted an increase in PGF2α synthesis (P < 0.02), and the effects differed among the animals (P < 0.04). The PGF2a production was higher in the explants treated with PDBu rather than OT (13.68 ± 1.16 vs. 10.01 ± 1.16 pg/mL/mg tissue, respectively; P < 0.05). In conclusion, PGF2α synthesis is modulated by the presence of the DF (local E2) but not the CL (local P4), and both PDBu and OT stimulated PGF2a synthesis.(AU)

A prostaglandina F2α (PGF2α) determina a luteólise em bovinos. A capacidade de manipular sua síntese endógena é indispensável para a produção animal em grande escala. O estradiol (E2) e a progesterona (P4) modulam diversas vias moleculares das células endometriais, incluindo a síntese de PGF2α; no entanto, pouco se sabe sobre seus mecanismos específicos. Este trabalho investigou a produção in vitro e a possível modulação da PGF2α endometrial devido a um efeito local do E2 endógeno no corno uterino ipsilateral ao folículo dominante (FD) ou da P4 no corno ipsilateral ao corpo lúteo (CL). Os estimuladores de PGF2α oxitocina (OT) e 12,23-dibutirato de forbol (PDBu) foram incubados com explantes endometriais, e o conteúdo de PGF2α foi mensurado. Para tal, vacas cíclicas foram sincronizadas, o desenvolvimento de FD e CL foi examinado por ultrassonografia, e no 17º dia do ciclo estral os explantes endometriais foram coletados e cultivados em meio ou suplementados com PDBu 10-6M ou 10-6M OT. As amostras de meio foram coletadas imediatamente após o tratamento e sessenta minutos depois. O radioimunoensaio mostrou que o conteúdo de PGF2α do corno ipsilateral ao FD foi 49% menor que o do corno contralateral (8,22 ± 0,95 vs. 12,24 ± 0,95 pg/mL/mg de tecido, respectivamente, P < 0,01). No entanto, os níveis de PGF2α não diferiram entre os cornos em função da posição do CL (9,46 ± 0,95 versus 11 ± 0,95 pg/mL/mg; P > 0,05). Os estimuladores celulares promoveram um aumento na síntese de PGF2α (P < 0,02), e os efeitos diferiram entre os animais (P < 0,04). A produção de PGF2α foi maior nos explantes tratados com PDBu em comparação à OT (13,68 ± 1,16 versus 10,01 ± 1,16 pg/mL/mg de tecido, respectivamente, P < 0,05). A conclusão obtida foi que a síntese de PGF2α é: modulada pela presença do FD (E2 local), mas não do CL (P4 local); e estimulada por PDBu e OT.(AU)

Endometrial prostaglandin F2α in vitro production and its modulation regarding dominant follicle position in cattle / Produção in vitro de PGF F2α endometrial e sua modulação referente ao folículo dominante em bovinos

Prostaglandin F2α (PGF2α) determines luteolysis in cattle, and the ability to manipulate its endogenous synthesis is indispensible for large-scale animal breeding. Estradiol (E2) and progesterone (P4) modulate several molecular pathways in endometrial cells, including the synthesis of PGF2α; however, its specific mechanisms are still not totally known. This study investigated the production in vitro and possible modulation of endometrial PGF2α due to a local effect of endogenous E2 in the ipsilateral uterine horn (UH) containing the dominant follicle (DF) or from P4 in ipsilateral horn containing the corpus luteum (CL). The PGF2α stimulators oxytocin (OT) and phorbol 12,13-dibutyrate (PDBu) were incubated with endometrial explants, and PGF2α content was measured. For that, cycling cows were synchronized, the development of DF and CL was examined by ultrasonography and on the seventh day of the estrous cycle, endometrial explants were collected and cultured in medium supplemented with 10-6 M PDBu or 10-6 M OT or non-supplemented. Media samples were collected immediately after treatment and 60 min later. Radioimmunoassay showed that the PGF2α content of the UH ipsilateral to the DF was 49% less than that of the contralateral UH (8.22 ± 0.95 vs. 12.24 ± 0.95 pg/mL/mg tissue, respectively; P < 0.01). However, the PGF2α levels did not differ between the UHs as a function of the CL position (9.46 ± 0.95 vs. 11 ± 0.95 pg/mL/mg; P > 0.05). The cellular stimulators promoted an increase in PGF2α synthesis (P < 0.02), and the effects differed among the animals (P < 0.04). The PGF2a production was higher in the explants treated with PDBu rather than OT (13.68 ± 1.16 vs. 10.01 ± 1.16 pg/mL/mg tissue, respectively; P < 0.05). In conclusion, PGF2α synthesis is modulated by the presence of the DF (local E2) but not the CL (local P4), and both PDBu and OT stimulated PGF2a synthesis.(AU)

A prostaglandina F2α (PGF2α) determina a luteólise em bovinos. A capacidade de manipular sua síntese endógena é indispensável para a produção animal em grande escala. O estradiol (E2) e a progesterona (P4) modulam diversas vias moleculares das células endometriais, incluindo a síntese de PGF2α; no entanto, pouco se sabe sobre seus mecanismos específicos. Este trabalho investigou a produção in vitro e a possível modulação da PGF2α endometrial devido a um efeito local do E2 endógeno no corno uterino ipsilateral ao folículo dominante (FD) ou da P4 no corno ipsilateral ao corpo lúteo (CL). Os estimuladores de PGF2α oxitocina (OT) e 12,23-dibutirato de forbol (PDBu) foram incubados com explantes endometriais, e o conteúdo de PGF2α foi mensurado. Para tal, vacas cíclicas foram sincronizadas, o desenvolvimento de FD e CL foi examinado por ultrassonografia, e no 17º dia do ciclo estral os explantes endometriais foram coletados e cultivados em meio ou suplementados com PDBu 10-6M ou 10-6M OT. As amostras de meio foram coletadas imediatamente após o tratamento e sessenta minutos depois. O radioimunoensaio mostrou que o conteúdo de PGF2α do corno ipsilateral ao FD foi 49% menor que o do corno contralateral (8,22 ± 0,95 vs. 12,24 ± 0,95 pg/mL/mg de tecido, respectivamente, P < 0,01). No entanto, os níveis de PGF2α não diferiram entre os cornos em função da posição do CL (9,46 ± 0,95 versus 11 ± 0,95 pg/mL/mg; P > 0,05). Os estimuladores celulares promoveram um aumento na síntese de PGF2α (P < 0,02), e os efeitos diferiram entre os animais (P < 0,04). A produção de PGF2α foi maior nos explantes tratados com PDBu em comparação à OT (13,68 ± 1,16 versus 10,01 ± 1,16 pg/mL/mg de tecido, respectivamente, P < 0,05). A conclusão obtida foi que a síntese de PGF2α é: modulada pela presença do FD (E2 local), mas não do CL (P4 local); e estimulada por PDBu e OT.(AU)

Spermatozoa: A Historical Perspective.

The 100,000th scientific article on the subject of spermatozoa was recently published. Numerous studies evaluated the characteristics of this important cell that led to tremendous discoveries. Since its first observation and description in 1677, many important characteristics have been described regarding this highly fascinating gamete. In this review, we intend to provide a historical account of the numerous milestones and breakthroughs achieved related to spermatozoa. We conducted a review of the literature by selecting the most important subjects with regards to spermatozoa. Since their discovery by van Leeuwenhoek, spermatozoa have been studied by scientists to better understand their physiology and process of interaction with their female counterpart, the oocyte, in order to treat and resolve infertility problems. Three centuries after van Leeuwenhoek's discovery, the 100,000th article about these cells was published. It is encouraging that sperm research reached this landmark, but at the same time it is clear that further research on male reproductive physiology and spermatozoa is required to shed more light on their function and pathology in order to reduce the number of unexplained infertility cases.

Cipionato De Estradiol E Benzoato De Estradiol Em Protocolos De Inseminação Artificial Em Tempo Fixo Em Novilhas Mestiças / Estradiol Cypionate And Estradiol Benzoate In Artificial Insemination Protocols In Fixed Time In Heifers Crossbred / Cipionato De Estradiol Y Benzoato De Estradiol En Los Protocolos De Inseminación Artificial En Tiempo Fijo En Vaquillas Mestizas

Avaliou-se a eficiência de dois indutores da ovulação: cipionato de estradiol (CE) e benzoato de estradiol (BE), na inseminação artificial em tempo fixo (IATF). Foram utilizadas 128 novilhas. Todos os animais foram submetidos ao mesmo protocolo de sincronização, a partir do dia 8 os animais foram distribuídos em dois tratamentos: Tratamento com CE no dia 8 (64 novilhas) e tratamento com BE no dia 9 (64 novilhas). Quanto ao número de folículos, só observou-se diferença significativa entre os tratamentos no dia 8. Não houve diferença (p>0,05) para taxa de crescimento folicular, diâmetro do folículo dominante (10,97 ± 1,24 e 9,77 ± 1,36 mm), e intervalo da ovulação à inseminação artificial (13,20 ± 3,79 e 23,00 ± 14,28 horas) entre os tratamentos. A retirada do dispositivo de progesterona à ovulação, em horas, foi de 60,60±3,69 e 74,75±15,17 horas, respectivamente para CE e BE (p 0,05). Houve diferença (p 0,05) entre os tratamentos para a taxa de ovulação, que foi de 90,00% e 40,00% para CE e BE, respectivamente. A taxa de prenhez foi de 37,3% (p0,05) para ambos tratamentos. A administração de CE no dia 8 possibilitou a redução de um manejo na IATF em novilhas sem influenciar na taxa de prenhez.

We evaluated the efficiency of two ovulation induction: estradiol cypionate (EC) and estradiol benzoate (EB), at fixed time artificial insemination (TAI). 128 heifers were used. All animals were subjected to the same synchronization protocol, from the 8th day animals were divided into two treatments: Treatment with CE on the 8th (64 heifers) and treatment with EB on Day 9 (64 heifers). Regarding the number of follicles, only there was a significant difference between treatments at day 8. There was no difference (p> 0.05) for follicular growth rate, diameter of the dominant follicle (10.97 ± 1.24 and 9, 77 ± 1.36 mm) and range of ovulation in artificial insemination (13.20 ± 3.79 and 23.00 ± 14.28 hours) between treatments. The withdrawal of progesterone device ovulation in hours was 60.60 ± 3.69 and 74.75 ± 15,17 hours respectively for CE and BE (p <0.05). There were differences (p <0.05) between treatments for ovulation rate, which was 90.00% and 40.00% for CE and BE, respectively. The pregnancy rate was 37.3% (p 0.05) for both treatments. The EC administration on 81 Centro enabled the reduction of management in the TAI in heifers without influencing pregnancy rate.

Se evaluó la eficiencia de la inducción de la ovulación de dos: cipionato de estradiol (CE) y benzoato de estradiol (EB), en la inseminación artificial de tiempo fijo (TAI). Se utilizaron 128 novillas. Todos los animales fueron sometidos al mismo protocolo de sincronización, a partir de los animales se dividieron en dos tratamientos 8º: El tratamiento con CE en la octava (64 novillas) y el tratamiento con EB en el Día 9 (64 novillas). En cuanto al número de folículos, solamente había una diferencia significativa entre los tratamientos en el día 8. No hubo diferencia (p> 0,05) para la tasa de crecimiento folicular, el diámetro del folículo dominante (10,97 ± 1,24 y 9, 77 ± 1,36 mm) y el rango de la ovulación en la inseminación artificial (13,20 ± 3,79 y 23,00 ± 14,28 horas) entre tratamientos. La retirada del dispositivo de progesterona ovulación en horas fue 60,60 ± 3,69 y 74,75 ± 15,17 horas, respectivamente, para el CE y BE (p <0,05). Hubo diferencias (p <0,05) entre los tratamientos para la tasa de ovulación, que fue 90,00% y 40,00% para CE y ser, respectivamente. La tasa de embarazo fue de 37,3% (p 0,05) en ambos tratamientos. La administración CE el 8 de activar la reducción de la gestión en el TAI en novillas sin influir en la tasa de embarazo.

Understanding the uterine environment in early pregnancy in cattle: How have the omicsenhanced our knowledge?

Early pregnancy loss in cattle can be attributed to a myriad of sources. One key factor that can influence early pregnancy success or loss is the influence and interactions between the maternal environment and the developing embryo/conceptus. Recent advancesin high-throughput ‘omics' technologies coupled with improved bioinformatics capabilities represent a promising avenue for enhancing our understanding of fundamental developmental events– which would have direct agricultural, veterinary, and economic benefits. Thusly this review revolves around recent applications of advanced transcriptomic, proteomic, and metabolomic analyses within a bovine uterine secretomic and interactomic context, with an overriding aim to highlight the advantages of these emerging fields whilst identify ingareas for improvement, consideration, and further research and development.

Cipionato De Estradiol E Benzoato De Estradiol Em Protocolos De Inseminação Artificial Em Tempo Fixo Em Novilhas Mestiças / Estradiol Cypionate And Estradiol Benzoate In Artificial Insemination Protocols In Fixed Time In Heifers Crossbred / Cipionato De Estradiol Y Benzoato De Estradiol En Los Protocolos De Inseminación Artificial En Tiempo Fijo En Vaquillas Mestizas

Avaliou-se a eficiência de dois indutores da ovulação: cipionato de estradiol (CE) e benzoato de estradiol (BE), na inseminação artificial em tempo fixo (IATF). Foram utilizadas 128 novilhas. Todos os animais foram submetidos ao mesmo protocolo de sincronização, a partir do dia 8 os animais foram distribuídos em dois tratamentos: Tratamento com CE no dia 8 (64 novilhas) e tratamento com BE no dia 9 (64 novilhas). Quanto ao número de folículos, só observou-se diferença significativa entre os tratamentos no dia 8. Não houve diferença (p>0,05) para taxa de crescimento folicular, diâmetro do folículo dominante (10,97 ± 1,24 e 9,77 ± 1,36 mm), e intervalo da ovulação à inseminação artificial (13,20 ± 3,79 e 23,00 ± 14,28 horas) entre os tratamentos. A retirada do dispositivo de progesterona à ovulação, em horas, foi de 60,60±3,69 e 74,75±15,17 horas, respectivamente para CE e BE (p 0,05). Houve diferença (p 0,05) entre os tratamentos para a taxa de ovulação, que foi de 90,00% e 40,00% para CE e BE, respectivamente. A taxa de prenhez foi de 37,3% (p0,05) para ambos tratamentos. A administração de CE no dia 8 possibilitou a redução de um manejo na IATF em novilhas sem influenciar na taxa de prenhez.(AU)

We evaluated the efficiency of two ovulation induction: estradiol cypionate (EC) and estradiol benzoate (EB), at fixed time artificial insemination (TAI). 128 heifers were used. All animals were subjected to the same synchronization protocol, from the 8th day animals were divided into two treatments: Treatment with CE on the 8th (64 heifers) and treatment with EB on Day 9 (64 heifers). Regarding the number of follicles, only there was a significant difference between treatments at day 8. There was no difference (p> 0.05) for follicular growth rate, diameter of the dominant follicle (10.97 ± 1.24 and 9, 77 ± 1.36 mm) and range of ovulation in artificial insemination (13.20 ± 3.79 and 23.00 ± 14.28 hours) between treatments. The withdrawal of progesterone device ovulation in hours was 60.60 ± 3.69 and 74.75 ± 15,17 hours respectively for CE and BE (p <0.05). There were differences (p <0.05) between treatments for ovulation rate, which was 90.00% and 40.00% for CE and BE, respectively. The pregnancy rate was 37.3% (p 0.05) for both treatments. The EC administration on 81 Centro enabled the reduction of management in the TAI in heifers without influencing pregnancy rate.(AU)

Se evaluó la eficiencia de la inducción de la ovulación de dos: cipionato de estradiol (CE) y benzoato de estradiol (EB), en la inseminación artificial de tiempo fijo (TAI). Se utilizaron 128 novillas. Todos los animales fueron sometidos al mismo protocolo de sincronización, a partir de los animales se dividieron en dos tratamientos 8º: El tratamiento con CE en la octava (64 novillas) y el tratamiento con EB en el Día 9 (64 novillas). En cuanto al número de folículos, solamente había una diferencia significativa entre los tratamientos en el día 8. No hubo diferencia (p> 0,05) para la tasa de crecimiento folicular, el diámetro del folículo dominante (10,97 ± 1,24 y 9, 77 ± 1,36 mm) y el rango de la ovulación en la inseminación artificial (13,20 ± 3,79 y 23,00 ± 14,28 horas) entre tratamientos. La retirada del dispositivo de progesterona ovulación en horas fue 60,60 ± 3,69 y 74,75 ± 15,17 horas, respectivamente, para el CE y BE (p <0,05). Hubo diferencias (p <0,05) entre los tratamientos para la tasa de ovulación, que fue 90,00% y 40,00% para CE y ser, respectivamente. La tasa de embarazo fue de 37,3% (p 0,05) en ambos tratamientos. La administración CE el 8 de activar la reducción de la gestión en el TAI en novillas sin influir en la tasa de embarazo.(AU)

Understanding the uterine environment in early pregnancy in cattle: How have the omicsenhanced our knowledge?

Early pregnancy loss in cattle can be attributed to a myriad of sources. One key factor that can influence early pregnancy success or loss is the influence and interactions between the maternal environment and the developing embryo/conceptus. Recent advancesin high-throughput ‘omics' technologies coupled with improved bioinformatics capabilities represent a promising avenue for enhancing our understanding of fundamental developmental eventswhich would have direct agricultural, veterinary, and economic benefits. Thusly this review revolves around recent applications of advanced transcriptomic, proteomic, and metabolomic analyses within a bovine uterine secretomic and interactomic context, with an overriding aim to highlight the advantages of these emerging fields whilst identify ingareas for improvement, consideration, and further research and development.(AU)

Exame ginecológico e acompanhamento reprodutivo em éguas / Gynecological examination and monitoring reproductive in mares

O exame ginecológico na espécie equina é de extrema importância para aumentar a eficiência reprodutiva dos animais, aproveitar suas características desejáveis e intensificar o melhoramento genético. Porém, a influência do fotoperíodo acarreta variações na incidência das ovulações nas éguas durante o decorrer do ano. Assim, o acompanhamento reprodutivo para predição da ovulação, utilização de hormônios ebiotecnologias torna-se essencial. Este trabalho aborda aspectos morfológicos dos órgãos genitais, aspectos da fisiologia reprodutiva e dinâmica folicular de éguas.

The gynecological examination in the equine species has an extreme importance to increase the reproductive efficiency of the animals, take the advantage of its desirable characteristics and intensify the genetic improvement. However, an influence of the photoperiod causes variations in the incidence of ovulation in the mares during the course of the year. Thus, reproductive monitoring for ovulation prediction, use of hormones and biotechnologies becomes essential. This work deals with themorphological aspects of the genital organs, the reproductive physiology and the follicular dynamics of mares.