Effect of heat stress on the survival and development of in vitro cultured bovine preantral follicles and on in vitro maturation of cumulus-oocyte complex.

The deleterious effect of heat stress (HS) on competence of oocytes from antral follicles is well recognized, but there is a lack of data regarding its impact on the viability and growth of preantral follicles. In this study, we used in vitro preantral follicle cultures to investigate the effects of HS on the following parameters: survival and development of primordial follicles after in vitro culture of ovarian fragments (experiment I); growth and antrum formation of isolated advanced secondary follicles (experiment II); and maturation rates after in vitro maturation (IVM) of cumulus-oocyte complexes (COCs) from antral follicles (>2-6 mm) grown in vivo (experiment III). Furthermore, the following end points were evaluated in all experiments: follicle/oocyte survival, reactive oxygen species (ROS), estradiol (E2) and progesterone (P4) production, as well as mRNA expression for select genes related to stress (HSP70) and apoptosis (MCL1 and BAX). In all experiments, HS consisted of exposing the structures (ovarian fragments, isolated preantral follicles and COCs) to 41 °C for 12 hours and then to 38.5 °C until the end of the culture (7 days for experiments I and II and 24 hours for experiment III). The temperature for the control group was held at 38.5 °C for the entire culture period. Heat stress increased (P < 0.05) the percentage of developing follicles (intermediate, primary, and secondary follicles) at 12 hours and increased levels of ROS at all evaluated time points (12, 24 hours, and D7), when compared to the control (experiment I). Heat stress did not affect (P > 0.05) any identified end points when preantral follicles were cultured in their isolated form (experiment II). However, in experiment III, HS decreased (P < 0.05) both the rates of metaphase II after 24 hours and E2 production at 12 hours of IVM. Moreover, HS increased (P < 0.0001) levels of P4 after IVM and ROS production at every evaluated time point, compared with the control (12 and 24 hours). In conclusion, HS caused: (1) early activation of primordial follicles; (2) an increase in ROS production by early preantral follicles enclosed in ovarian tissue and by COCs; (3) a short-term reduction of E2 production by COCs; and (4) an increase in P4 secretion from COCs. However, HS did not affect in vitro culture of advanced isolated secondary follicles. Experimental evidence indicates that preantral follicles are less sensitive to HS than COC.

Bone Morphogenetic Protein-6 (BMP-6) Stimulates the Antrum Formation by the Regulation of its Signalling Pathway in Caprine Pre-antral Follicles Cultured In Vitro.

BMP-6 has been found to be important to ovarian cells and oocyte, as well as to uterus. Thus, this study investigated the effect of bone morphogenetic protein (BMP-6) and recombinant follicle-stimulating hormone (rFSH) alone or in combination on the in vitro culture (IVC) of isolated caprine secondary follicles (Experiment 1) and the mRNA levels for BMP receptors/Smad signalling pathway (BMPR1A, BMPR2, SMAD1, SMAD4, SMAD5, SMAD6, SMAD7 and SMAD8) in vivo and in vitro using BMP-6 (Experiment 2). Secondary follicles were cultured in αMEM(+) alone (control medium) or supplemented with BMP-6 at 1 or 10 ng/ml and rFSH alone or the combination of both BMP-6 concentrations and rFSH. The results from Experiment 1 showed that the antrum formation rate was higher in the BMP-6 at 1 ng/ml (p < 0.05) than in MEM. In Experiment 2, the mRNA expression for BMPR2, SMAD1, SMAD5 and SMAD6 was detected in non-cultured control and after in vitro culture (MEM and 1 ng/ml BMP-6); while the expression of SMAD7 and SMAD8 mRNA was only detected after IVC, SMAD4 was only detected in the BMP-6 at 1 ng/ml treatment. In conclusion, the low BMP-6 concentration positively influenced antrum formation and ensured normal mRNA expression for BMP receptor and Smads after IVC of caprine secondary follicles.

Proteoma uterino durante o ciclo reprodutivo e gestação em animais domésticos / Uterine proteomics during the reproductive cycle and pregnancy in domestic animals

A abordagem proteômica tem permitido estudos da expressão proteica em diferentes tecidos e fluidoscorporais, em condiç ões e/ou momentos distintos. O recente progresso de metodologias nessa área tem permitidoo estudo de moléculas responsáveis por processos biológicos na reprodução animal. Dessa forma, este trabalhobuscou relatar os principais estudos abordando o proteoma uterino durante o ciclo reprodutivo e a gestação emanimais domésticos. O estudo da dinâmica molecular uterina tem permitido a identificação de proteínas compapel biológico na reprodução de fêmeas domésticas, gerando perspectiva tanto para a aplicação debiotecnologias quanto para o diagnóstico e o tratamento precoce de alterações reprodutivas.(AU)

Proteomic approach has allowed studies of protein expression in different tissues and body fluids indiscrete conditions and/or time points. Recent advances of methodologies in this field have allowed the study ofmolecules responsible for biological processes in animal reproduction. Thus this study aimed to report the mainstudies addressing the uterine proteome during the reproductive cycle and pregnancy in domestic animals. Thestudy of uterine molecular dynamics has allowed the identification of proteins with biological role in femalereproduction of domestic generating prospect for application of biotechnology and early diagnosis andtreatment of reproductive disturbances.(AU)

Proteoma uterino durante o ciclo reprodutivo e gestação em animais domésticos / Uterine proteomics during the reproductive cycle and pregnancy in domestic animals

A abordagem proteômica tem permitido estudos da expressão proteica em diferentes tecidos e fluidoscorporais, em condiç ões e/ou momentos distintos. O recente progresso de metodologias nessa área tem permitidoo estudo de moléculas responsáveis por processos biológicos na reprodução animal. Dessa forma, este trabalhobuscou relatar os principais estudos abordando o proteoma uterino durante o ciclo reprodutivo e a gestação emanimais domésticos. O estudo da dinâmica molecular uterina tem permitido a identificação de proteínas compapel biológico na reprodução de fêmeas domésticas, gerando perspectiva tanto para a aplicação debiotecnologias quanto para o diagnóstico e o tratamento precoce de alterações reprodutivas.

Proteomic approach has allowed studies of protein expression in different tissues and body fluids indiscrete conditions and/or time points. Recent advances of methodologies in this field have allowed the study ofmolecules responsible for biological processes in animal reproduction. Thus this study aimed to report the mainstudies addressing the uterine proteome during the reproductive cycle and pregnancy in domestic animals. Thestudy of uterine molecular dynamics has allowed the identification of proteins with biological role in femalereproduction of domestic generating prospect for application of biotechnology and early diagnosis andtreatment of reproductive disturbances.

Impact of growth hormone (GH) and follicle stimulating hormone (FSH) on in vitro canine preantral follicle development and estradiol production.

OBJECTIVE: Evaluate the effect of different concentrations of growth hormone (GH) on the in vitro development of domestic dog (Canis lupus familiaris) preantral follicles in the presence or absence of follicle stimulating hormone (FSH). METHODS: Secondary preantral follicles, isolated by microdissection, were cultured in a medium composed of αMEM with bovine serum albumin (BSA), glutamine, hypoxanthine, insulin, transferrin, selenium and ascorbic acid (αMEM(+)-control) added at different concentrations of GH (GH10 ng/ml or GH50 ng/ml) and FSH (GH10+FSH, GH50+FSH). Follicle development was evaluated based on the percentage of intact follicles, antrum formation, follicular diameter, follicular viability using fluorescent markers and estradiol production. RESULTS: GH50 was the only treatment that maintained the same percentage of normal morphologically follicles from day 0 to day 18 of culture (P<0.05). For all treatments, except the control, follicles were viable throughout the 18 days of culture (P<0.05). GH50 supplemented with FSH (GH50+FSH) resulted in the highest average follicular diameter (P<0.05) from day 12 to 18. Follicles from both the control and the GH50+FSH treatment groups actively and increasingly secreted estradiol from day 6 to 18 of culture (P<0.05). CONCLUSIONS: Our study demonstrates that GH benefits the maintenance of follicular morphology in a dose-dependent manner and, in association with FSH, stimulates in vitro follicular growth and estradiol production.

Semen variables and sperm membrane protein profile of Saanen bucks (Capra hircus) in dry and rainy seasons of the northeastern Brazil (3°S).

The Saanen is a highly productive breed, and for this reason, it has been raised in Brazil, but mostly under climate conditions completely different from where the breed originated. The objective of this study was to investigate variations in semen parameters and sperm membrane proteins from Saanen bucks (n = 7) raised in Northeastern Brazil, during dry season (September, October, and November) and rainy season (March, April, and May). We showed that during the dry season, sperm motility, concentration, and the percentage of normal sperm decreased as compared to the rainy season. Rectal temperatures of bucks had no significant (p > 0.05) variations during the dry and rainy seasons. However, temperatures of left and right skin testis were higher (p < 0.05) during the dry as compared to the rainy season. Expression of three proteins (lysine-specific demethylase 5D, adenosine triphosphate (ATP) synthase subunit d, and radial spoke head protein 9 homolog) in sperm membrane were more intense in rainy season and only one protein (cytosol aminopeptidase) had greater expression in the dry season of the year. Our results show that mechanisms of testicular thermoregulation of Saanen bucks did not prevent a decrease in seminal parameters during the dry season. This deterioration may be related to reduced expression of proteins associated with important functions in sperm membrane.

Proteínas do plasma seminal canino: revisão / Protein patterns of canine seminal plasma: review

Nas últimas décadas, o crescente interesse pela cinofilia motivou o crescimento de uma atividadecomercial lucrativa. Assim, há um interesse em aumentar a performance reprodutiva por meio de biotécnicas dareprodução, como a criopreservação de gametas e a inseminação artificial. A identificação de proteínas presentesno plasma seminal canino dá início a novas discussões sobre o uso de proteínas em aditivos que melhorem aviabilidade espermática e possam ser usados como método contraceptivo em cadelas. Dessa forma, este trabalhoobjetivou descrever as proteínas do plasma seminal canino verificadas na literatura científica, como alactoferrina, a arginina esterase, as proteínas ligadoras de heparina, a osteopontina e as proteínas ligadoras dezinco, assim como relacioná-las com suas respectivas funções diante da esfera reprodutiva.(AU)

In the past few years, the interesting in dogs has provided an increase of this commercial activity. Thus,there is an interest in the increase of reproductive performance using biotechnology such as semencryopreservation and artificial insemination. The identification of proteins present in seminal plasma canineamazed initiates further discussion on the use of protein additives that improve sperm viability and it can used ascontraception in female dogs. Thus, this study aimed to describe the canine seminal plasma proteins, describedin the scientific literature, such as lactoferrin, arginine esterase, the heparin-binding proteins, osteopontin andzinc binding proteins, as well as relate them to their respective functions on the reproductive sphere.(AU)

Proteínas do plasma seminal canino: revisão / Protein patterns of canine seminal plasma: review

Nas últimas décadas, o crescente interesse pela cinofilia motivou o crescimento de uma atividadecomercial lucrativa. Assim, há um interesse em aumentar a performance reprodutiva por meio de biotécnicas dareprodução, como a criopreservação de gametas e a inseminação artificial. A identificação de proteínas presentesno plasma seminal canino dá início a novas discussões sobre o uso de proteínas em aditivos que melhorem aviabilidade espermática e possam ser usados como método contraceptivo em cadelas. Dessa forma, este trabalhoobjetivou descrever as proteínas do plasma seminal canino verificadas na literatura científica, como alactoferrina, a arginina esterase, as proteínas ligadoras de heparina, a osteopontina e as proteínas ligadoras dezinco, assim como relacioná-las com suas respectivas funções diante da esfera reprodutiva.

In the past few years, the interesting in dogs has provided an increase of this commercial activity. Thus,there is an interest in the increase of reproductive performance using biotechnology such as semencryopreservation and artificial insemination. The identification of proteins present in seminal plasma canineamazed initiates further discussion on the use of protein additives that improve sperm viability and it can used ascontraception in female dogs. Thus, this study aimed to describe the canine seminal plasma proteins, describedin the scientific literature, such as lactoferrin, arginine esterase, the heparin-binding proteins, osteopontin andzinc binding proteins, as well as relate them to their respective functions on the reproductive sphere.

O estudo proteômico e o seu potencial de avaliação da fertilidade em machos de diferentes espécies domésticas / The proteomic approach and its potential for fertility assessment in males of different domestic species

A abordagem proteômica permite identificar componentes proteicos, celulares e secreções. Desta forma, constitui uma ferramenta viável para o estudo das potenciais funções de proteínas e para a busca por marcadores proteicos de fenótipos específicos e/ou processos fisiológicos. Este trabalho teve por objetivo fazer uma revisão sobre esse tema e sua importância na biotecnologia do sêmen de machos domésticos. A composição da membrana espermática e do plasma seminal é de grande interesse, em virtude da sua influência nos eventos de fusão oócito-espermatozoide, fertilização e subsequente desenvolvimento embrionário. Diversos trabalhos vêm demonstrando o potencial da proteômica ligada à reprodução animal, a qual auxilia na identificação de marcadores de fertilidade ou de ejaculados aptos à congelação.(AU)

The proteomic approach allows the identification of proteins from tissues, cells and secretion. Thus, this tool is useful for the study of potential protein functions and search for markers of specific phenotypes and/or physiological events. This study aimed to review on the subject and its importance in semen biotechnology of several species. The composition of the sperm membrane and seminal plasma is of great interest because of its influence on sperm-oocyte fusion, fertilization and subsequent embryonic development. Several studies have demonstrated the potential of proteomics related to animal breeding, assisting in identifying markers for fertility or able to ejaculate process of freezing / thawing in males of several species.(AU)

Plasma seminal ovino e sua aplicação na biotecnologia reprodutiva / Ram seminal plasma and use in reproductive biotechnology

O plasma seminal de ovinos tem importante atuação na função espermática e na fertilização. Em ovinos, a adição do plasma seminal ou de suas proteínas tem apresentado resultados favoráveis na qualidade do sêmen ovino criopreservado. Entretanto, resultados divergentes têm sido obtidos, possivelmente relacionados à variação da composição do plasma seminal. Compreender a função e os mecanismos que envolvem a interação plasma seminal-espermatozoide poderia ajudar na formulação de diluidores seminais e aperfeiçoar protocolos de criopreservação. (AU)

The ram seminal plasma plays a important role in sperm function and fertilization. The addition of seminal plasma or its proteins has presented favorable results in cryopreserved ram semen quality. However, divergent result has been obtained, possibly related to variation in the composition of seminal plasma. Understand the role and mechanisms involved in sperm-seminal plasma interaction could help to formulating seminal extenders and improve cryopreservation protocols.(AU)

Plasma seminal ovino e sua aplicação na biotecnologia reprodutiva / Ram seminal plasma and use in reproductive biotechnology

O plasma seminal de ovinos tem importante atuação na função espermática e na fertilização. Em ovinos, a adição do plasma seminal ou de suas proteínas tem apresentado resultados favoráveis na qualidade do sêmen ovino criopreservado. Entretanto, resultados divergentes têm sido obtidos, possivelmente relacionados à variação da composição do plasma seminal. Compreender a função e os mecanismos que envolvem a interação plasma seminal-espermatozoide poderia ajudar na formulação de diluidores seminais e aperfeiçoar protocolos de criopreservação.

The ram seminal plasma plays a important role in sperm function and fertilization. The addition of seminal plasma or its proteins has presented favorable results in cryopreserved ram semen quality. However, divergent result has been obtained, possibly related to variation in the composition of seminal plasma. Understand the role and mechanisms involved in sperm-seminal plasma interaction could help to formulating seminal extenders and improve cryopreservation protocols.

O estudo proteômico e o seu potencial de avaliação da fertilidade em machos de diferentes espécies domésticas / The proteomic approach and its potential for fertility assessment in males of different domestic species

A abordagem proteômica permite identificar componentes proteicos, celulares e secreções. Desta forma, constitui uma ferramenta viável para o estudo das potenciais funções de proteínas e para a busca por marcadores proteicos de fenótipos específicos e/ou processos fisiológicos. Este trabalho teve por objetivo fazer uma revisão sobre esse tema e sua importância na biotecnologia do sêmen de machos domésticos. A composição da membrana espermática e do plasma seminal é de grande interesse, em virtude da sua influência nos eventos de fusão oócito-espermatozoide, fertilização e subsequente desenvolvimento embrionário. Diversos trabalhos vêm demonstrando o potencial da proteômica ligada à reprodução animal, a qual auxilia na identificação de marcadores de fertilidade ou de ejaculados aptos à congelação.

The proteomic approach allows the identification of proteins from tissues, cells and secretion. Thus, this tool is useful for the study of potential protein functions and search for markers of specific phenotypes and/or physiological events. This study aimed to review on the subject and its importance in semen biotechnology of several species. The composition of the sperm membrane and seminal plasma is of great interest because of its influence on sperm-oocyte fusion, fertilization and subsequent embryonic development. Several studies have demonstrated the potential of proteomics related to animal breeding, assisting in identifying markers for fertility or able to ejaculate process of freezing / thawing in males of several species.

Sperm parameters and biochemical components of goat seminal plasma in the rainy and dry seasons in the Brazilian Northeast: the season's influence on the cooling of semen / Caracrterísticas espermáticas e bioquímicas do plasma seminal de caprinos nas estações chuvosa e seca do Nordeste brasileiro: influência da estação no resfriamento do sêmen

The present study aimed to verify the caprine semen characteristics during dry and rainy seasons in the Brazilian Northeast, and the influence of these seasons on cooled semen. Seminal volume, concentration, percentage of motile cells, vigor and spermatic morphology, as well as biochemical profile (fructose, citric acid, P, Ca2+, Mg, total proteins and phospholipase A2 activity) were analyzed. It was observed a reduction (P<0.05) in normal sperm morphology, fructose, citric acid, P, Mg and total protein concentration during the dry season, which did not affect the motility, vigor, volume and sperm concentration. Phospholipase A2 activity was increased during the dry season (P<0.05). The analysis of the semen cooled at 4ºC during 48 hours showed reduction in total motility and vigor sperm during the dry season (P<0.05). Based on these results, we conclude that the best period of year for caprine semen cooling is the rainy season.

Verificou-se as características seminais de caprinos durante a época seca e a chuvosa no Nordeste brasileiro e a influência da época no resfriamento do sêmen. Foram mensurados volume, concentração espermática, porcentagem de espermatozoides móveis, vigor, morfologia espermática e características bioquímicas (frutose, ácido cítrico, fósforo, magnésio, proteínas totais e atividade da fosfolipase A2). Observou-se redução (P<0,05) no número de espermatozóides morfologicamente normais, frutose, ácido cítrico, fósforo, magnésio e proteínas totais durante a época seca que não influenciaram na motilidade, vigor, volume e concentração do sêmen. Entretanto, a atividade da fosfolipase A2 foi maior na época seca. Quando o sêmen foi submetido ao resfriamento a 4ºC durante 48 horas, houve redução (P<0,05) na motilidade total e no vigor espermático durante a época seca. Com base nesses resultados, conclui-se que o período chuvoso é melhor para resfriar sêmen de caprinos no Nordeste brasileiro.

Dynamic medium containing growth differentiation factor-9 and FSH maintains survival and promotes in vitro growth of caprine preantral follicles after long-term in vitro culture.

The aim of the present study was to evaluate the effects of growth differentiation factor 9 (GDF-9) and FSH on the in vitro development of caprine preantral follicles cultured for 16 days. Ovarian fragments were cultured in αMEM⁺ (α-minimum essential medium, pH 7.2-7.4, 10 µg mL⁻¹ insulin, 5.5 µg mL⁻¹ transferrin, 5.0 ng mL⁻¹ selenium, 2 mM glutamine, 2 mM hypoxanthine and 1.25 mg mL⁻¹ bovine serum albumin) in the absence or presence of 200 ng mL⁻¹ GDF-9 and/or 50 ng mL⁻¹ FSH added during the first (Days 0-8) and/or second (Days 8-16) half of the culture period. Non-cultured and cultured fragments were processed for histological and ultrastructural analyses. After 16 days, all treatments using GDF-9 or FSH showed higher rates of follicular survival compared with αMEM⁺ alone. Compared with non-cultured control, sequential culture media containing GDF-9 and/or FSH significantly increased the percentage of developing follicles and follicle diameter. Moreover, a progressive increase in oocyte diameter was observed only with sequential culture medium containing GDF-9 until Day 8 followed by FSH (GDF-9/FSH) in the second half of the culture period. After 16 days of culture, ultrastructural analysis confirmed the integrity of follicles cultured in the presence of GDF-9/FSH. In conclusion, a dynamic medium containing GDF-9 and FSH (GDF-9/FSH) maintained follicular integrity and promoted activation of primordial follicles and growth during long-term in vitro culture of goat preantral follicles.

The effects of epidermal growth factor (EGF) on the in vitro development of isolated goat secondary follicles and the relative mRNA expression of EGF, EGF-R, FSH-R and P450 aromatase in cultured follicles.

The effects of varying concentrations of EGF were evaluated in terms of in vitro follicular development and the mRNA expression levels of EGF, EGF-R, FSH-R and P450 aromatase. After 6 days, the addition of 50 ng/mL of EGF to the culture medium increased the antrum formation rates in comparison to cultured control and after 18 days of culture produced oocytes with higher rates of meiosis resumption when compared to the other treatments (P<0.05). The daily follicular growth rates in presence of EGF (50 or 100) were increased in comparison to the cultured control (P<0.05). Treatment with EGF 50 stimulated the expression of EGF mRNA but reduced EGF-R mRNA expression and estradiol secretion as compared to the cultured control (P<0.05). After 18 days of culture, the mRNA levels for FSH-R and P450 aromatase were greater than those of the non-cultured controls (P<0.05). In conclusion, the effects of EGF treatment on the mRNA levels for EGF, EGF-R, FSH-R, and P450 aromatase varied according to the stage of follicle development.

Sperm parameters and biochemical components of goat seminal plasma in the rainy and dry seasons in the Brazilian Northeast: the season's influence on the cooling of semen / Caracrterísticas espermáticas e bioquímicas do plasma seminal de caprinos nas estações chuvosa e seca do Nordeste brasileiro: influência da estação no resfriamento do sêmen

The present study aimed to verify the caprine semen characteristics during dry and rainy seasons in the Brazilian Northeast, and the influence of these seasons on cooled semen. Seminal volume, concentration, percentage of motile cells, vigor and spermatic morphology, as well as biochemical profile (fructose, citric acid, P, Ca2+, Mg, total proteins and phospholipase A2 activity) were analyzed. It was observed a reduction (P<0.05) in normal sperm morphology, fructose, citric acid, P, Mg and total protein concentration during the dry season, which did not affect the motility, vigor, volume and sperm concentration. Phospholipase A2 activity was increased during the dry season (P<0.05). The analysis of the semen cooled at 4ºC during 48 hours showed reduction in total motility and vigor sperm during the dry season (P<0.05). Based on these results, we conclude that the best period of year for caprine semen cooling is the rainy season.(AU)

Verificou-se as características seminais de caprinos durante a época seca e a chuvosa no Nordeste brasileiro e a influência da época no resfriamento do sêmen. Foram mensurados volume, concentração espermática, porcentagem de espermatozoides móveis, vigor, morfologia espermática e características bioquímicas (frutose, ácido cítrico, fósforo, magnésio, proteínas totais e atividade da fosfolipase A2). Observou-se redução (P<0,05) no número de espermatozóides morfologicamente normais, frutose, ácido cítrico, fósforo, magnésio e proteínas totais durante a época seca que não influenciaram na motilidade, vigor, volume e concentração do sêmen. Entretanto, a atividade da fosfolipase A2 foi maior na época seca. Quando o sêmen foi submetido ao resfriamento a 4ºC durante 48 horas, houve redução (P<0,05) na motilidade total e no vigor espermático durante a época seca. Com base nesses resultados, conclui-se que o período chuvoso é melhor para resfriar sêmen de caprinos no Nordeste brasileiro.(AU)

Impacto do estresse térmico na reprodução da fêmea bovina / Heat stress impact on reproduction of bovine female

Com o objetivo de melhorar os índices de produtividade de seus rebanhos, muitos criadores de regiões tropicais têm optado pela aquisição de animais especializados oriundos de regiões de clima temperado com condições climáticas bem diferenciadas das dos trópicos. Devido às altas temperaturas tropicais, estes animais estão constantemente susceptíveis ao estresse térmico, uma vez que não são dotados de mecanismos anatomo-fisiológicos necessários para manter a homeotermia, resultando em prejuízos para a produção e reprodução animal. Portanto, esta revisão tem por objetivo discorrer sobre os efeitos negativos do estresse térmico sobre a reprodução, enfocando aspectos relacionados à atividade ovariana e à mortalidade embrionária.(AU)

Aiming to improve the productivity rates of their herds, many farmers in tropical regions have opted for the acquisition of specialized animals come from temperate regions with weather conditions so different from those found in the tropics. Due to high tropical temperatures, these animals are constantly susceptible to heat stress; because they do not have anatomical and physiological mechanisms to maintain efficiently its homeostasis, resulting in prejudices to production and reproduction performances. This review aims to discuss the adverse effects of heat stress on female reproduction, emphasizing some aspects involved in ovarian activity and embryo mortality.(AU)

Impacto do estresse térmico na reprodução da fêmea bovina / Heat stress impact on reproduction of bovine female

Com o objetivo de melhorar os índices de produtividade de seus rebanhos, muitos criadores de regiões tropicais têm optado pela aquisição de animais especializados oriundos de regiões de clima temperado com condições climáticas bem diferenciadas das dos trópicos. Devido às altas temperaturas tropicais, estes animais estão constantemente susceptíveis ao estresse térmico, uma vez que não são dotados de mecanismos anatomo-fisiológicos necessários para manter a homeotermia, resultando em prejuízos para a produção e reprodução animal. Portanto, esta revisão tem por objetivo discorrer sobre os efeitos negativos do estresse térmico sobre a reprodução, enfocando aspectos relacionados à atividade ovariana e à mortalidade embrionária.

Aiming to improve the productivity rates of their herds, many farmers in tropical regions have opted for the acquisition of specialized animals come from temperate regions with weather conditions so different from those found in the tropics. Due to high tropical temperatures, these animals are constantly susceptible to heat stress; because they do not have anatomical and physiological mechanisms to maintain efficiently its homeostasis, resulting in prejudices to production and reproduction performances. This review aims to discuss the adverse effects of heat stress on female reproduction, emphasizing some aspects involved in ovarian activity and embryo mortality.

Avaliação de espermatozoides caprinos congelados em meio à base de água de coco em pó (ACP-101®) ou TRIS / Evaluation of goat spermatozoa frozen in media based on powder coconut water media based (ACP-101®) or TRIS

Compararam-se as características cinéticas e morfológicas de espermatozoides caprinos congelados nos meios à base de ACP-101® e TRIS. Os diluentes utilizados foram: ACP-101® (+ 2,5 por cento gema ovo + 7 por cento glicerol) e TRIS (+ 20 por cento gema ovo + 6,8 por cento glicerol). Quarenta e oito ejaculados de quatro bodes foram coletados, avaliados, divididos em duas alíquotas e diluídos nos meios ACP-101® e TRIS, respectivamente, posteriormente congelados e, após 30 dias, descongelados. A avaliação da motilidade espermática por computador foi realizada aos 5, 60 e 120 minutos pós-descongelação. As características de motilidade espermática analisadas foram: motilidade total (MT) ( por cento) e progressiva (MP) ( por cento), velocidades média do trajeto do espermatozoide (VAP) (µm/s) e linear (VSL) (µm/s) e população de espermatozoides rápidos (ER) ( por cento). As avaliações de morfologia espermática quantificaram a porcentagem de espermatozoides normais (N) e as alterações da cabeça (AC), da peça intermediária (API) e do flagelo (AF), aos cinco e 120 minutos pós-descongelação. O diluente TRIS apresentou resultados cinéticos mais elevados que o ACP-101® aos 60 e 120 minutos pós-descongelação. As AC aos 120 minutos pós-descongelação foram mais altas nos espermatozoides congelados em ACP-101®. Conclui-se que o diluente TRIS promoveu maior viabilidade in vitro dos espermatozoides caprinos pós-descongelação.(AU)

The aim of the work was to compare kinetic and morphologic characteristics of goat sperm frozen in diluent media based on ACP-101® and TRIS. The employed diluents were: ACP-101® (+ 2.5 percent egg yolk + 7 percent glycerol) and TRIS (+ 20 percent egg yolk + 6.8 percent glycerol). Forty eight ejaculates from four bucks were collected, assessed and divided into two aliquots and diluted into the experimental treatments ACP-101® and TRIS. The samples were frozen and after 30 days, thawed. The computer assisted spermatic motility evaluations were placed into 5, 60 and 120 minutes post-thawing. The motion parameters assessed were: total motility (MT) ( percent), progressive motility (MP) ( percent), average path velocity (VAP) (µm/s), straight linear velocity (VSL) (µm/s), and population of rapid spermatozoa (ER) ( percent). The morphologic parameters: normal spermatozoa (N), head alteration (AC), intermediary piece alteration (API), tail alteration (AF) were evaluated at 5 and 120 min post-thawing. The media based on TRIS showed kinetic results significantly superior to ACP-101® at 60 and 120min. After 120min post-thawing the AC was higher in frozen sperm in media based on ACP-101®. The TRIS media promoted better goat spermatozoa in vitro viability post-thawing.(AU)

Avaliação de espermatozoides caprinos congelados em meio à base de água de coco em pó (ACP-101®) ou TRIS / Evaluation of goat spermatozoa frozen in media based on powder coconut water media based (ACP-101®) or TRIS

Compararam-se as características cinéticas e morfológicas de espermatozoides caprinos congelados nos meios à base de ACP-101® e TRIS. Os diluentes utilizados foram: ACP-101® (+ 2,5 por cento gema ovo + 7 por cento glicerol) e TRIS (+ 20 por cento gema ovo + 6,8 por cento glicerol). Quarenta e oito ejaculados de quatro bodes foram coletados, avaliados, divididos em duas alíquotas e diluídos nos meios ACP-101® e TRIS, respectivamente, posteriormente congelados e, após 30 dias, descongelados. A avaliação da motilidade espermática por computador foi realizada aos 5, 60 e 120 minutos pós-descongelação. As características de motilidade espermática analisadas foram: motilidade total (MT) ( por cento) e progressiva (MP) ( por cento), velocidades média do trajeto do espermatozoide (VAP) (µm/s) e linear (VSL) (µm/s) e população de espermatozoides rápidos (ER) ( por cento). As avaliações de morfologia espermática quantificaram a porcentagem de espermatozoides normais (N) e as alterações da cabeça (AC), da peça intermediária (API) e do flagelo (AF), aos cinco e 120 minutos pós-descongelação. O diluente TRIS apresentou resultados cinéticos mais elevados que o ACP-101® aos 60 e 120 minutos pós-descongelação. As AC aos 120 minutos pós-descongelação foram mais altas nos espermatozoides congelados em ACP-101®. Conclui-se que o diluente TRIS promoveu maior viabilidade in vitro dos espermatozoides caprinos pós-descongelação.

The aim of the work was to compare kinetic and morphologic characteristics of goat sperm frozen in diluent media based on ACP-101® and TRIS. The employed diluents were: ACP-101® (+ 2.5 percent egg yolk + 7 percent glycerol) and TRIS (+ 20 percent egg yolk + 6.8 percent glycerol). Forty eight ejaculates from four bucks were collected, assessed and divided into two aliquots and diluted into the experimental treatments ACP-101® and TRIS. The samples were frozen and after 30 days, thawed. The computer assisted spermatic motility evaluations were placed into 5, 60 and 120 minutes post-thawing. The motion parameters assessed were: total motility (MT) ( percent), progressive motility (MP) ( percent), average path velocity (VAP) (µm/s), straight linear velocity (VSL) (µm/s), and population of rapid spermatozoa (ER) ( percent). The morphologic parameters: normal spermatozoa (N), head alteration (AC), intermediary piece alteration (API), tail alteration (AF) were evaluated at 5 and 120 min post-thawing. The media based on TRIS showed kinetic results significantly superior to ACP-101® at 60 and 120min. After 120min post-thawing the AC was higher in frozen sperm in media based on ACP-101®. The TRIS media promoted better goat spermatozoa in vitro viability post-thawing.