Concentration of soybean lecithin affects short-term storage success of goat semen related with seminal plasma removal

The objective of this study was to investigate the need of seminal plasma removal for short-term cooling of buck semen in soybean lecithin (SL) based extender. Each pool was divided equally, and one half was subjected to centrifugation to remove seminal plasma (SP-), while the other half remained with seminal plasma (SP+). Then, both SP+ and SP- samples were diluted in two SL extenders (extender A = 1% SL; extender B = 2% SL), cooled to 5ºC and stored for 48 hours. The sperm kinetics, evaluated by CASA, and plasma membrane integrity (PMI), acrosomal integrity (ACI) and high mitochondrial membrane potential (HMMP), evaluated by epifluorescence microscopy, were determined within five minutes after reaching 5°C (T0), as well as after 24 (T24) and 48 (T48) hours of storage. Interactions (seminal plasma vs. extender vs. time;) were observed for all variables assessed. Total and progressive motility and other variables of sperm kinetics decreased after 24 hours of cooling in the SP+ group, and after 48 hours of storage, these same variables were lower in SP+/B compared to SP-/B groups. Furthermore, SP+ reduced PMI (extender B, T48), HMMP (A and B extenders, T48) and ACI (extender A, T0) compared to SP- samples. The interactions between seminal plasma and soybean lecithin phospholipids seemed to occur in a time-dependent manner. It was concluded that the removal of seminal plasma improves the quality of goat semen that was cooled in a soybean lecithin-based extender, especially when using 2% soybean lecithin.(AU)

Concentration of soybean lecithin affects short-term storage success of goat semen related with seminal plasma removal

The objective of this study was to investigate the need of seminal plasma removal for short-term cooling of buck semen in soybean lecithin (SL) based extender. Each pool was divided equally, and one half was subjected to centrifugation to remove seminal plasma (SP-), while the other half remained with seminal plasma (SP+). Then, both SP+ and SP- samples were diluted in two SL extenders (extender A = 1% SL; extender B = 2% SL), cooled to 5ºC and stored for 48 hours. The sperm kinetics, evaluated by CASA, and plasma membrane integrity (PMI), acrosomal integrity (ACI) and high mitochondrial membrane potential (HMMP), evaluated by epifluorescence microscopy, were determined within five minutes after reaching 5°C (T0), as well as after 24 (T24) and 48 (T48) hours of storage. Interactions (seminal plasma vs. extender vs. time;) were observed for all variables assessed. Total and progressive motility and other variables of sperm kinetics decreased after 24 hours of cooling in the SP+ group, and after 48 hours of storage, these same variables were lower in SP+/B compared to SP-/B groups. Furthermore, SP+ reduced PMI (extender B, T48), HMMP (A and B extenders, T48) and ACI (extender A, T0) compared to SP- samples. The interactions between seminal plasma and soybean lecithin phospholipids seemed to occur in a time-dependent manner. It was concluded that the removal of seminal plasma improves the quality of goat semen that was cooled in a soybean lecithin-based extender, especially when using 2% soybean lecithin.

Fatores envolvidos na criopreservação do sêmen caprino / Factors involved in the cryopreservation of goat semen

Ao longo dos anos, tem-se observado um maior interesse em técnicas que possibilitem um melhor aproveitamento do material genético de reprodutores, em geral. Entretanto, para caprinos, a criopreservação seminal ainda tem alguns entraves, uma vez que não há um protocolo ideal, visando maximizar a utilização de boa qualidade e viabilidade. Nesse contexto, o presente trabalho tem como objetivo abordar os principais passos envolvidos na tecnologia da criopreservação do sêmen caprino, abrangendo desde a refrigeração, congelação, diluentes e crioprotetores, até a influência do plasma seminal sobre esses processos; com o intuito de aumentar o conhecimento das necessidades das células espermáticas, durante todas as etapas e colaborar para desenvolvimento de protocolos mais eficientes; favorecendo, assim, o melhoramento genético de animais de alto potencial.

Over the years, there has been a greater interest in technique that allow a better use of the genetic material of breeding herders in general. However, for goats, seminal cryopreservation still has some obstacles, since it does not have an ideal protocol, aiming to maximize the use of good quality and viability. In this context, the present work aims to address the main steps involved in the cryopreservation technology of goat semen, ranging from refrigeration, freezing, diluents and cryoprotectants to the influence of seminal plasma on these processes; With the aim of increasing the knowledge of the needs of spermatic cells during all the stages and collaborate to develop more efficient protocols, thus favoring the genetic improvement of high genetic animals.

Impact of heat stress, nutritional stress and combined (heat and nutritional) stresses on rumen associated fermentation characteristics, histopathology and HSP70 gene expression in goats

A study was conducted to assess the impact of heat stress, nutritional stress and combined stresses (heat and nutritional stress) on rumen fermentation characteristics, histopathology of rumen and rumen HSP70 gene expression in goats. Twenty four adult Osmanabadi bucks were divided into four groups, C (n=6; control), HS (n=6; heat stress), NS (n=6; nutritional stress) and CS (n=6; combined stress). The study was conducted for a period of 45 days. The C and HS bucks had ad libitum access to their feed while NS and CS bucks were subjected to restricted feed (30% intake of C bucks) to induce nutritional stress. The HS and CS bucks were exposed to heat stress in an outside environment. Both feed intake and body weight were significantly (p < 0.01) lower in CS and NS groups. The carboxy methyl cellulase activities - extracellular, intracellular and total activity in the rumen fluid differed significantly (p < 0.01) between the groups. The highest concentration of ammonia nitrogen (p < 0.05) was recorded in C while the lowest in the CS group. The concentration of total nitrogen and trichloroacetic acid precipitable N, propionic acid, butyric acid, and valeric acid was lower (p < 0.01) in the restricted fed (NS and CS) bucks as compared to ad libitum fed groups (C and HS). Further, the ratio of acetate to propionate (A: P ratio) was also significantly (p < 0.01) higher in CS and NS groups. The higher expression of rumen heat shock protein 70 (HSP70) mRNA was observed in CS goats. The histopathological section of rumen revealed a reduction in the length of rumen villi and thickness in CS, whereas rumen keratinization was highest in the CS group. From the study it can be concluded that when two stresses occur simultaneously, they may have severe impact on rumen fermentation characteristics of bucks.(AU)

Fatores envolvidos na criopreservação do sêmen caprino / Factors involved in the cryopreservation of goat semen

Ao longo dos anos, tem-se observado um maior interesse em técnicas que possibilitem um melhor aproveitamento do material genético de reprodutores, em geral. Entretanto, para caprinos, a criopreservação seminal ainda tem alguns entraves, uma vez que não há um protocolo ideal, visando maximizar a utilização de boa qualidade e viabilidade. Nesse contexto, o presente trabalho tem como objetivo abordar os principais passos envolvidos na tecnologia da criopreservação do sêmen caprino, abrangendo desde a refrigeração, congelação, diluentes e crioprotetores, até a influência do plasma seminal sobre esses processos; com o intuito de aumentar o conhecimento das necessidades das células espermáticas, durante todas as etapas e colaborar para desenvolvimento de protocolos mais eficientes; favorecendo, assim, o melhoramento genético de animais de alto potencial.(AU)

Over the years, there has been a greater interest in technique that allow a better use of the genetic material of breeding herders in general. However, for goats, seminal cryopreservation still has some obstacles, since it does not have an ideal protocol, aiming to maximize the use of good quality and viability. In this context, the present work aims to address the main steps involved in the cryopreservation technology of goat semen, ranging from refrigeration, freezing, diluents and cryoprotectants to the influence of seminal plasma on these processes; With the aim of increasing the knowledge of the needs of spermatic cells during all the stages and collaborate to develop more efficient protocols, thus favoring the genetic improvement of high genetic animals.(AU)

Impact of heat stress, nutritional stress and combined (heat and nutritional) stresses on rumen associated fermentation characteristics, histopathology and HSP70 gene expression in goats

A study was conducted to assess the impact of heat stress, nutritional stress and combined stresses (heat and nutritional stress) on rumen fermentation characteristics, histopathology of rumen and rumen HSP70 gene expression in goats. Twenty four adult Osmanabadi bucks were divided into four groups, C (n=6; control), HS (n=6; heat stress), NS (n=6; nutritional stress) and CS (n=6; combined stress). The study was conducted for a period of 45 days. The C and HS bucks had ad libitum access to their feed while NS and CS bucks were subjected to restricted feed (30% intake of C bucks) to induce nutritional stress. The HS and CS bucks were exposed to heat stress in an outside environment. Both feed intake and body weight were significantly (p < 0.01) lower in CS and NS groups. The carboxy methyl cellulase activities - extracellular, intracellular and total activity in the rumen fluid differed significantly (p < 0.01) between the groups. The highest concentration of ammonia nitrogen (p < 0.05) was recorded in C while the lowest in the CS group. The concentration of total nitrogen and trichloroacetic acid precipitable N, propionic acid, butyric acid, and valeric acid was lower (p < 0.01) in the restricted fed (NS and CS) bucks as compared to ad libitum fed groups (C and HS). Further, the ratio of acetate to propionate (A: P ratio) was also significantly (p < 0.01) higher in CS and NS groups. The higher expression of rumen heat shock protein 70 (HSP70) mRNA was observed in CS goats. The histopathological section of rumen revealed a reduction in the length of rumen villi and thickness in CS, whereas rumen keratinization was highest in the CS group. From the study it can be concluded that when two stresses occur simultaneously, they may have severe impact on rumen fermentation characteristics of bucks.

Protective effects of fruit-juices on sperm viability of West African Dwarf goat bucks during cryopreservation

The present study was conducted to determine the effects of adding fruit-juices to semen extenders on viability of buck spermatozoa during cryopreservation in two studies. Pooled semen samples obtained from West African Dwarf (WAD) goat bucks were diluted with Tris-egg yolk based extenders. In study I, the diluted semen samples were supplemented with orange (Citrus sinensis), cucumber (Cucumis sativus) and pineapple (Ananas comosus) juices (2.5, 5, 7.5 and 10 ml/100 ml). In study II, the diluted semen samples were supplemented with 5 ml/100 ml of different combinations of fruitjuices consisting of pineapple and orange juices (TEYPO) at a 1:1 ratio, pineapple and cucumber juices (TEYPC) at a 1:1 ratio, orange and cucumber juices (TEYOC) at a 1:1 ratio, and pineapple, orange and cucumber juices (TEYPOC) at a 1:1:1 ratio, respectively. The diluted semen samples were cryopreserved and thereafter evaluated for sperm viability parameters. The extenders supplemented with 7.5 and 10% orange, and 10% pineapple had higher (P < 0.05) motility compared to the control. There was higher (P < 0.05) acrosome integrity in extenders supplemented with orange and pineapple at all levels compared to the control while cucumber at 10% had higher (P < 0.05) acrosome integrity compared to other levels and the control. The extenders supplemented with cucumber, orange and pineapple had higher (P < 0.05) membrane integrity compared to the control except at 7.5% of extender supplemented with cucumber. Similarly, the extenders supplemented with cucumber, orange and pineapple had lower (P < 0.05) sperm abnormality compared to the control. The extenders supplemented with cucumber, orange and pineapple at 2.5, 10 and 7.5% respectively had lower (P < 0.05) concentrations of MDA compared to other levels and the control...

Protective effects of fruit-juices on sperm viability of West African Dwarf goat bucks during cryopreservation

The present study was conducted to determine the effects of adding fruit-juices to semen extenders on viability of buck spermatozoa during cryopreservation in two studies. Pooled semen samples obtained from West African Dwarf (WAD) goat bucks were diluted with Tris-egg yolk based extenders. In study I, the diluted semen samples were supplemented with orange (Citrus sinensis), cucumber (Cucumis sativus) and pineapple (Ananas comosus) juices (2.5, 5, 7.5 and 10 ml/100 ml). In study II, the diluted semen samples were supplemented with 5 ml/100 ml of different combinations of fruitjuices consisting of pineapple and orange juices (TEYPO) at a 1:1 ratio, pineapple and cucumber juices (TEYPC) at a 1:1 ratio, orange and cucumber juices (TEYOC) at a 1:1 ratio, and pineapple, orange and cucumber juices (TEYPOC) at a 1:1:1 ratio, respectively. The diluted semen samples were cryopreserved and thereafter evaluated for sperm viability parameters. The extenders supplemented with 7.5 and 10% orange, and 10% pineapple had higher (P < 0.05) motility compared to the control. There was higher (P < 0.05) acrosome integrity in extenders supplemented with orange and pineapple at all levels compared to the control while cucumber at 10% had higher (P < 0.05) acrosome integrity compared to other levels and the control. The extenders supplemented with cucumber, orange and pineapple had higher (P < 0.05) membrane integrity compared to the control except at 7.5% of extender supplemented with cucumber. Similarly, the extenders supplemented with cucumber, orange and pineapple had lower (P < 0.05) sperm abnormality compared to the control. The extenders supplemented with cucumber, orange and pineapple at 2.5, 10 and 7.5% respectively had lower (P < 0.05) concentrations of MDA compared to other levels and the control...(AU)

EFEITO MACHO ASSOCIADO A PROGRAMA DE LUZ E SINCRONIZAÇÃO DO ESTRO COM CLOPROSTENOL EM CABRAS LEITEIRAS NA CONTRA-ESTAÇÃO REPRODUTIVA

A eficiência da associação da indução do estro pelo programa de luz seguida da administração de cloprostenol e efeito macho foi estudada em cabras Saanen acíclicas submetidas ao programa de luz (16 h de luz e 8 h de escuridão) por 60 dias (D0-D60). Cabras multíparas e nulíparas foram alocadas em baias com (T1, n = 67 multíparas; T3, n = 41 nulíparas) ou sem (T2, n = 61 multíparas; T4, n = 34 nulíparas) bode vasectomizado (D120-D135 para multíparas e D120-171 para nulíparas). T1, T2 e T4 receberam duas doses de 120 µg de cloprostenol no D135 (manhã) e no D142 (tarde). A dinâmica folicular ovariana foi acompanhada de D0 a D176 em intervalos diferentes. A inseminação artificial foi realizada 10 a 24 h após o início do estro em T1 e T2, enquanto T3 foram cobertas por monta natural controlada. T1 (85,2%) e T3 (91,7%) apresentaram maior frequência (P<0,05) de corpos lúteos (CL) do que T2 (48,8%) e T4 (23,8%) na primeira dose de cloprostenol/efeito macho, mas não ocorreu no momento da 2ª dose de cloprostenol (P>0,05). A taxa de gestação ajustada em 30d diferiram (P<0,05) entre T1 vs. T2 (21,7 e 42,0%) e T3 vs. T4 (98,0 e 63,7%). T1 apresentou maior frequência de CL funcional quando comparado a T2 e T4 (96,9 vs. 66,7%) em D176. Em conclusão, a associação do programa de luz com o efeito macho mostrou-se uma alternativa viável para indução de estro sincronizado em cabras Saanen e a presença de machos foi capaz de eliminar o efeito da ordem de parto em cabritas nulíparas na contra-estação reprodutiva.

The efficiency of combining estrus induction by light program followed by cloprostenol administration and male effect was tested in acyclic Saanen goats were submitted to light program (16 h of light and 8 h of darkness) for 60 days (D0-D60). Multiparous and nulliparous goats were allocated in pains with (T1, n = 67 multiparous; T3, n = 41 nulliparous) or without (T2, n = 61 multiparous; T4, n = 34 nulliparous) vasectomized buck (D120-D135 to multiparous and D120-171 to nulliparous). T1, T2 and T4 received two doses of 120 µg of cloprostenol on D135 (morning) and D142 (afternoon). Ovarian follicular dynamics were recorded from D0 to D176 at different intervals. Artificial insemination was performed 10 to 24 h after estrous onset in T1 and T2 while T3 were hand-mated. T1 (85.2%) and T3 (91.7%) present more (P < 0.05) corpora lutea (CL) than T2 (48.8%) and T4 (23.8%) at the first cloprostenol dose/male effect but not at the time of the 2nd cloprostenol dose (P>0.05). The 30d adjusted gestation rates differed (P<0.05) between T1 vs. T2 (21.7 and 42.0%) and T3 vs. T4 (98.0 and 63.7%). T1 showed a higher frequency of functional CL when compared to T2 and T4 (96.9 vs. 66.7%) at D176. In conclusion, the association of light treatment with male effect proved to be a viable alternative for induction of synchronized estrus on Saanen goats and the male presence was able to eliminate the effect of parity on nulliparous goats at non-breeding season.

Male effect and breeding season shortening under contrasting climatic conditions upon reproduction of nulliparous Anglo-Nubians / Efeito do macho e redução das estações de monta em diferentes condições climática a reprodução de nulíparas Anglo-Nubiana

This study was aimed to evaluate breeding seasons of different durations under contrasting climatic conditions upon reproductive performance of nulli­parous does submitted to male effect. A total of 240 Anglo-Nubian females at 8 to 12 months of age were used and were kept away from all three bucks at a distance of 300 m for 60 days, which avoided any physical, visual, olfactory or hearing contact between genders. Estrus were visually detected and pregnancy rates were determined by ultrasonography 60 days after the last mating. Breeding season duration and climatic condition did not influence estrus incidence, where 70% does had estrus detected at the dry season, 80% of does cycled at the rainy season within breeding seasons of 25 days. Moreover, 80% of does cycled at the dry season and 95% at the rainy season during breeding seasons of 35 days and 45 days. After breeding seasons of 25 days, pregnancy rate was lower at the dry season (55.0%) compared to the rainy season (80.0%). Mean birth weight of resulting offspring was lower during the rainy season (2.94 kg ± 0.26) than during the dry season (3.03 kg ± 0.16). The results show that estrus onset is affected by breeding season durations and climatic conditions tested, although dry season lowered pregnancy rates. In conclusion, 25-day breeding seasons are recommended to improve standardization of offspring lots, to reduce costs with food supplementation and estrus detection, while preserving pregnancy and kidding rates.

Male effect and breeding season shortening under contrasting climatic conditions upon reproduction of nulliparous Anglo-Nubians / Efeito do macho e redução das estações de monta em diferentes condições climática a reprodução de nulíparas Anglo-Nubiana

This study was aimed to evaluate breeding seasons of different durations under contrasting climatic conditions upon reproductive performance of nulli­parous does submitted to male effect. A total of 240 Anglo-Nubian females at 8 to 12 months of age were used and were kept away from all three bucks at a distance of 300 m for 60 days, which avoided any physical, visual, olfactory or hearing contact between genders. Estrus were visually detected and pregnancy rates were determined by ultrasonography 60 days after the last mating. Breeding season duration and climatic condition did not influence estrus incidence, where 70% does had estrus detected at the dry season, 80% of does cycled at the rainy season within breeding seasons of 25 days. Moreover, 80% of does cycled at the dry season and 95% at the rainy season during breeding seasons of 35 days and 45 days. After breeding seasons of 25 days, pregnancy rate was lower at the dry season (55.0%) compared to the rainy season (80.0%). Mean birth weight of resulting offspring was lower during the rainy season (2.94 kg ± 0.26) than during the dry season (3.03 kg ± 0.16). The results show that estrus onset is affected by breeding season durations and climatic conditions tested, although dry season lowered pregnancy rates. In conclusion, 25-day breeding seasons are recommended to improve standardization of offspring lots, to reduce costs with food supplementation and estrus detection, while preserving pregnancy and kidding rates.(AU)

EFEITO DA MELATONINA SOBRE A QUALIDADE DO SÊMEN CONGELADO DE CAPRINOS

Objetivou-se neste estudo determinar o efeito da adição da melatonina a diferentes diluidores de criopreservação do sêmen caprino, sobre os parâmetros de cinética e viabilidade espermática pós-descongelação. Cinco pools de sêmen, obtidos de 3 reprodutores caprinos, foram congelados em diluidor à base de leite desnatado (LD) ou gema de ovo (TGO) e suplementados com diferentes concentrações de melatonina (0 mM, 0,5 mM, 1 mM, 2 mM e 4 mM). Após a descongelação, as amostras foram avaliadas nos momentos 0 e após 2 horas de incubação (37 oC), quanto aos parâmetros cinéticos e de viabilidade (integridade de membranas plasmática e acrossomal, potencial de membrana mitocondrial e produção intracelular de ROS). Os dados foram analisados usando o procedimento Glimmix do SAS. O sêmen congelado-descongelado em LD demonstrou maiores (p < 0,05) valores de cinética espermática, quando comparado ao TGO. Em relação aos parâmetros de viabilidade observou-se que o TGO proporcionou maior (p < 0,05) valor de alto potencial de membrana mitocondrial que o LD, não sendo demonstrado diferenças entre os diluidores nos demais parâmetros avaliados. A suplementação da melatonina influenciou (p < 0,05) nos parâmetros de cinética e viabilidade do sêmen caprino congeladodescongelado, sendo os valores obtidos na concentração de 4 mM de melatonina inferior (p < 0,05) ao do grupo controle. Em conclusão, os parâmetros cinéticos pós-descongelação e a viabilidade após duas horas de incubação foram aceitáveis em ambos os diluidores e isso sugere a potencial utilidade do sêmen caprino criopreservado. Verificou-se que o diluidor a base de leite desnatado resulta em melhor desempenho in vitro em comparação ao de gema de ovo. Além disso, a adição de 4 mM de melatonina em qualquer meio diluidor é deletéria a qualidade do sêmen pós descongelação. Menores concentrações de melatonina testadas, apesar de não deletérias não influenciam a qualidade espermática.

The objective of this study was determine the effects of the addition of melatonin on different cryopreservation diluents for goat semen, and its effects on the kinetic parameters and postthawing sperm viability. Five semen pools, obtained from three male goats, were frozen using extenders based on skimmed milk (SM) or egg yolk (EY), and supplemented with different concentrations of melatonin (0 mM, 0.5 mM, 1 mM, 2 mM and 4 mM). After thawing, samples were evaluated at 0 and after 2 h incubation at (37 °C) for kinetic and viability parameters (plasma and acrosomal membrane integrity, mitochondrial membrane potential and intracellular production of ROS). Data were analyzed using the Glimmix SAS procedure. The frozen-thawed semen in SM showed higher (p <0.05) sperm kinetic values when compared to EY. Regarding the viability parameters, it was observed that the EY provided a higher (p <0.05) high mitochondrial membrane potential value than the SM, and no differences were found among the extenders in the other parameters evaluated. The melatonin supplementation influenced (p <0.05) the kinetic and viability parameters of the frozen-thawed goat semen, being the values obtained in the concentration of 4 mM melatonin lower than in the control group (p <0.05). In conclusion, post-thaw kinetic parameters and viability after two hours of incubation were acceptable in both extenders, this suggests the potential utilization of cryopreserved goat semen. Was found that the skimmed milk extender improved in vitro performance better than egg yolk. Moreover, the addition of 4 mM melatonin in any extender is deleterious to post-thaw semen quality. Lower concentrations of melatonin tested, despite no deleterious effects observed, did not improve the sperm quality.

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)

Concentrações plasmáticas de testosterona, triiodotironina (T3) e tiroxina (T4) em bodes submetidos ao estresse calórico / Plasma concentrations of testosterone, triiodothyronine (T3), and thyroxine (T4) in bucks submitted to heat stress

Para verificar o efeito do estresse calórico (EC) nas concentrações plasmáticas de testosterona, triiodotironina (T3) e tiroxina (T4), oito bodes, das raças Saanen (n=4) e Alpina (n=4), foram mantidos em câmara bioclimática, sob condições de termoneutralidade (13,0ºC a 26,7ºC) durante 30 dias e, após um período (60 dias) de descanso, submetidos ao EC (23,7ºC a 34,0ºC) por 30 dias. Para minimizar as variações sazonais nos perfis hormonais devido ao fotoperíodo, durante toda fase experimental, incluindo a de adaptação em condições de termoneutralidade (30 dias), o fotoperíodo foi controlado utilizando-se alternância de dias longos (16h de luz e 8h de escuro) e de dias curtos (8h de luz e 16h de escuro) a cada 30 dias. As amostras de sangue foram coletadas duas vezes por semana durante cinco semanas. No conjunto das raças, o EC não influenciou (P>0,05) as concentrações de testosterona (1,8±0,2 vs 1,3±0,2ng/ml) e nem a de T4 (52,7±2,8 vs 50,0±2,8ng/ml). Houve declínio (P<0,01) das concentrações de T3 nos animais submetidos ao experimento (1,3±0,1 vs 1,0±0,1ng/ml), mas a redução foi observada somente nos bodes Saanen. Em ambas as raças, as concentrações de T3 e T4 variaram (P<0,01) conforme o dia da coleta das amostras de sangue. O EC foi suficiente para produzir uma resposta fisiológica com redução das concentrações plasmáticas de T3 em bodes das raças Saanen, mas não da raça Alpina, assim como não foi capaz de alterar os níveis plasmáticos de testosterona e nem de T4.(AU)

To verify the effect of heat stress (HS) on plasma testosterone, triiodothyronine (T3), and thyroxine (T4) concentrations, eight Saanen (n=4) and Alpine Brown (n=4) bucks were kept in climate chamber under thermal neutral conditions (13.0ºC to 26.7ºC) for 30 days. After a resting period (60 days), the same bucks were submitted to heat stress (23.7ºC to 34.0ºC) for another 30 days. To neutralize the seasonal variations of hormonal profiles throughout the period, the photoperiod was controlled every 30 days altering long (16 hours of light and 8 hours of darkness) and short days (8 hours of light and 16 hours of darkness). The blood samples were collected twice a week during five weeks. In both breeds, there was no effect of HS (P>0.05) on plasma concentrations of testosterone (1.8±0.2 vs 1.3±0.2ng/ml) and T4 (52.7±2.8 vs 50.0±2.8ng/ml). There was a decline (P<0.01) of plasma T3 concentrations (1.3±0.1 vs 1.0±0.1ng/ml) after HS treatment, but this reduction was only evident in Saanen bucks. In both breeds, the plasma concentrations of T3 and T4 varied (P<0.01) according to the day of blood sample collection. The HS was sufficient to provoke a physiological response with reduction of plasma concentrations of thyroid hormones mainly of T3 in Saanen bucks, but not in Alpine ones. The HS did not affect the plasma testosterone and T4 levels.(AU)