Comportamento sócio-sexual e seus problemas no desempenho de touros / Social-sexual behaviour and its problems in performance of bulls

Esta revisão pretende discorrer sobre a estrutura social dos bovinos e sua relação com o comportamento sexual, a fisiologia reprodutiva e a fertilidade de touros a campo e em regime de coleta de sêmen, levando em consideração as diferentes fases do desenvolvimento sexual, os processos de aprendizado envolvidos e os efeitos do estresse social. À luz do conhecimento etológico serão feitas reflexões sobre o fitness (sucesso reprodutivo) de touros mantidos em manejo extensivo de criação e touros em Centrais de Coleta e Processamento de Sêmen (CCPS), a organização arquitetônica dos piquetes e área de coleta e a influência da proximidade de outros touros sobre a qualidade de todo o processo.(AU)

This review intends to discuss the cattle social structure and its relationship with sexual behavior, reproductive physiology, and fertility of bulls in the field and under semen collection regime, taking into account the distinct stages of sexual development, the learning processes involved and the effects of social stress. In the light of ethological science, we will reflect on the fitness (reproductive success) of bulls in extensive breeding management or bulls in Semen Collection and Processing Centers, their architectural organization of paddocks and collection area, and the influence of the proximity of other bulls on the quality of the entire process.(AU)

Cryopreservation of jaguar (Panthera onca) sperm cells using different cryoprotectants and different thawing temperatures

The cryopreservation of jaguar semen must be improved to produce high-quality biobanking doses. Until now, the rare studies of semen freezing in the species have only evaluated glycerol, always with a significant reduction in sperm quality in thawed semen. The purpose of this study was to assess the efficacy of three cryoprotectants, dimethylsulfoxide (DMSO), glycerol (GLY), and methanol (MET), in the cryopreservation of jaguar semen in an LDL-based extender, as well as the effect of thawing temperature on dosage quality. Five mature males with a history of reproduction were used. On the males, an infrared thermal image (IRT) was captured, the spicules and testes were analyzed, and the CASA system was used to evaluate the quality of fresh and thawed sperm. The superficial IRT was 4.6 ± 1.2 °C cooler than the anal sphincter, and the semen measured between 27.3 and 28.7 °C shortly after exiting the urethra. The total motility of fresh sperm was 55.3 ± 22.6%, and progressive motility was 36.3 ± 18%. The total motility of thawed sperm was 5.28 ± 2.51%, 4.49 ± %2.49, and 0.51 ± 0.62% for DMSO, GLY, and MET, respectively. DMSO and GLY performed better than MET, and there was no difference in thawing temperature (37°C 30 s vs. 50°C 12 s). All animals exhibit a considerable level of morphological changes in sperm. Low amounts of total and progressive motility were found in the thawed sperm. Males with a high level of sperm morphological changes were found to be fertile, but the lone male with normospermia was infertile. Thus, we contest the applicability of the commonly used morphological classification for bovines to felid species.(AU)

Impact of quercetin, carnosine, and ozone in the cryopreservation on Nellore (Bos indicus) semen

The objective of this study was to reduce the effects of cryoinjury caused in bovine semen by cryopreservation. Ejaculates were collected from Nellore bulls and subjected to freezing in C (control), ozone (15, 30, and 60 µg mL-1 of ozone), quercetin (25, 50, and 100 µg mL-1 of quercetin), and carnosine groups (100, 200, and 300 ng mL-1 of carnosine). Samples were evaluated post-thaw (M0) and post-rapid thermoresistance test (M30) for sperm kinetics (total motility, progressive motility, curvilinear speed, linearity and amplitude of lateral head displacement) and cell structure viability (plasma membrane integrity, acrosomal integrity, mitochondrial potential, membrane fluidity, and lipid peroxidation). There were no differences (P > 0.05) between the control, quercetin, and carnosine-treated groups for the parameters evaluated at M0 and M30. In turn, supplementation with ozone resulted in lower values for sperm kinetics (P < 0.05) and lower mitochondrial potential at M30 (P < 0.05). Quercetin and carnosine at the concentrations used did not promote significant gains in frozen semen, nor did they demonstrate cytotoxicity. We expected to obtain positive results with the use of ozone. Nonetheless, the addition was harmful to the parameters of sperm kinetics, and its effect was not observed as a possible pro-antioxidant. We believe that the fact that the gas did not harm the sperm structure opens avenues for tests with lower dosages, since, by reducing its concentration, we could minimize the damage to sperm kinetics.(AU0

Can detomidine replace medetomidine for pharmacological semen collection in domestic cats?

Among the different methods used for semen collection from domestic cats, the pharmacological collection by urethral catheterization becomes disruptive. Medetomidine is the elected α2-adrenoceptor agonist for that, but in several countries, it is not commercially available. This study aimed to evaluate the efficacy of detomidine compared to medetomidine in collecting semen by urethral catheterization in domestic cats. Urethral catheterization was performed on 13 mongrel cats using a disposable semi-rigid tomcat urinary catheter. Of the 19 semen collections performed with medetomidine induction, 94.7% were successful, while with detomidine induction, only 56.3% of 16 were successful. The values semen samples variables were as follows for volume - 10.56 ± 0.4 vs 8.88 ± 0.5 mL, motility - 171.67 ± 0.79 vs 49.77 ± 3.45%, vigor 4.1 ± 0.03 vs 3.10 ± 0.1 and concentration - 3.24 ± 0.19 vs 2.15 ± 0.13 ×109 sperm/mL respectively for medetomidine and detomidine group. The failure in semen collections with detomidine was mainly due to azoospermic samples, poor urethral relaxation, insufficient volume, or contamination of urine. The sperm concentration was also lower in the detomidine group (P<0.05) when compared to medetomidine. However, when the volume of semen collected was compared, we found no statistical differences. Despite its low performance in collecting semen from cats, detomidine may be an alternative when medetomidine is not accessible.(AU)

Effect of oleic-linoleic acid and beta-sitosterol to freezing extender of bulls and stallions semen / Efeito da adição de ácido oleico-linoleico e beta-sitosterol ao diluente de congelação do sêmen de touros e garanhões

Addition of polyunsaturated fatty acids and/or cholesterol to a freezing diluent can modify the sperm plasma membrane composition, influencing its behavior during cryopreservation, thus, favoring seminal cryoresistance. The present study aimed to evaluate the effects of the addition of oleic-linoleic acid, (OLA); beta-sitosterol (beta-sit), a plant analog of cholesterol; and OLA + beta-sit in combination to a freezing diluent, on the cryopreservation bull and stallion semen. The following variables were analyzed: motility/vigor, plasma and acrosomal membrane integrity (by Trypan Blue/Giemsa staining), mitochondrial activity (by DAB staining), and lipid peroxidation (by a TBARS assays). The lipids were added according to experimental treatments: C control group, A1 and A2 OLA at concentrations of 37 uM and 74 uM, B1 and B2 beta-sit at concentrations of 1 ug mL-1 and 2 ug mL-1; AB1 and AB2 OLA 37 uM + beta-sit 1 g mL-1 and OLA 74 uM + beta-sit 2 ug mL-1, respectively. The study was divided into three experiments; in Experiment 1, the concentrations of the groups A1, B1, and AB1 were evaluated, whereas in Experiment 2 the concentrations of the groups A2, B2, and AB2 were analyzed, both experiments were performed with bull semen. We conducted Experiment 3 using equine semen with the addition of lipids at all of the concentrations described. Data were subjected to analysis of variance, using the GLM procedure of SAS, with treatment means compared by Duncan test considering 5% significance. These variables differed significantly after thawing the semen post-collection. However, there was no significant difference between treatments when variables were compared within the same time point, except for Experiment 2, where there was a decrease in motility and vigor decrease post-thaw in the groups following β-sit addition (C 51.0 ± 13.7%/2.9 ± 0.4; B2 35.8 ± 15.8%/2.3 ± 0.6; AB2 38.5 ± 16.6%/2.5 ± 0.5, respectively; p < 0.05).(AU)

A adição de ácidos graxos poli-insaturados e/ou colesterol ao diluidor pode modificar a composição da membrana plasmática do espermatozoide, influenciando seu comportamento frente à criopreservação e favorecendo, assim, a crioresistência seminal. O presente trabalho teve como objetivo avaliar o efeito da adição do ácido oleico-linoleico (AOL), beta-sitosterol (beta-sit), um análogo vegetal do colesterol, e da associação AOL + beta-sit, ao diluente de congelação de sêmen bovino e equino. As variáveis analisadas foram motilidade/ vigor, integridade das membranas plasmática e acrossomais (Trypan Blue/Giemsa), atividade mitocondrial (DAB) e nível de peroxidação lipídica (TBARS). Os lipídios foram adicionados de acordo com os tratamentos experimentais: C grupo controle; A1 e A2 AOL nas concentrações de 37 uM e 74 uM; B1 e B2 beta-sit nas concentrações de 1 ug ml-1 e 2 ug ml-1; AB1 e AB2 AOL 37 uM + beta-sit 1 ug ml-1 e AOL 74 uM + beta-sit 2 ug ml-1, respectivamente. O trabalho consistiu de três experimentos, sendo que o Experimento 1 testou as concentrações dos grupos A1, B1 e AB1, e o Experimento 2 as concentrações dos grupos A2, B2 e AB2, ambos utilizando sêmen de touro. Para o Experimento 3 utilizou-se sêmen equino, sendo a adição dos lipídios feita em todas a concentrações descritas. Os dados foram submetidos à análise de variância, através do procedimento GLM do SAS, sendo as médias dos tratamentos comparadas pelo teste de Duncan em nível de 5% de significância. Os valores das variáveis avaliadas pós-descongelação diferiram significativamente daqueles obtidos pós-colheita, porém não foi observada diferença significativa entre os tratamentos quando as variáveis foram comparadas dentro do mesmo momento, exceto no Experimento 2, em que os valores de motilidade / vigor pós-descongelação nos grupos acrescidos do β-sit foram menores que os do controle (C 51,0 ± 13,7% / 2,9 ± 0,4; B2 35,8 ± 15,8% / 2,3 ± 0,6; AB2 38,5 ± 16,6% / 2,5 ± 0,5, respectivamente; p < 0,05).(AU)

Sazonalidade na congelabilidade de sêmen bovino / Seasonality in the freezability of bovine semen / Estacionalidad en congelamiento de semen bovino

O objetivo desta revisão foi apresentar e discutir os efeitos da sazonalidade nas características seminais de touros Bos taurus e Bos indicus antes e após o congelação, a fim de possibilitar maior rentabilidade econômica. Apesar da reprodução da espécie bovina não se caracterizar pela sazonalidade, estudos mostram a interferência das estações do ano na qualidade do sêmen de touros. O aumento da temperatura ambiente pode levar a elevação da temperatura testicular, das taxas metabólicas e das exigências de oxigênio, ocasionando alterações na espermatogênese e, por consequência, a um impacto negativo na reprodução. Touros Bos indicus obtêm melhor desempenho na estação mais quente do ano apresentando uma qualidade de sêmen satisfatória em relação a touros Bos taurus. Isso se deve à maior resistência dos zebuínos às altas temperaturas e a peroxidação lipídica causada pelo calor resultando em menor produção de espécies reativas ao oxigênio e menor aumento nos defeitos nas células espermáticas. Desse modo, touros de origem europeia não apresentam um bom desempenho durante alguns períodos mais quentes do ano o que leva a questionar se a relação custo-benefício de aproveitamento do sêmen para criopreservação justifica o processamento do mesmo pelas Centrais de Coleta e Processamento de Sêmen nesta época. Esse fato tem levado algumas empresas a suspender atividades em determinados meses do ano.(AU)

The objective of this review was to present and discuss the effects of seasonality in the semen characteristics of Bos taurus and Bos indicus bulls before and after freezing in order to enable greater economic profitability. Even though the bovine reproduction is not characterized by seasonality, studies have shown the interference of the season on semen quality in bulls. The increase of temperature may lead to increase in testicular temperature, metabolic rates and oxygen requirements. Both thermal and oxidative stress will cause changes in the normal development of spermatogenesis, changing volume, sperm concentration, progressive motility, vigor and morphology of sperm cells, resulting in an economically negative impact on reproduction. Bos indicus bulls presented better performance in the hottest season of the year, showing a satisfactory quality of semen when compared to Bos taurus bulls. This is due to the greater resistance to high temperatures of zebu bulls and lipid peroxidation caused by the heat resulting in lower production of species reactive to oxygen and smaller increases in defects in sperm cells. Thus, European bulls, such as Bos Taurus, do not present a good performance in some of the hottest periods of the year, which leads to questioning if the cost-effective use of semen cryopreservation justifies its processing by the Semen Collection and Processing Centers during these periods. This fact has led some national centers for semen suspend activities in certain months of the year.(AU)

El objetivo de esta revisión ha sido presentar y discutir los efectos de la estacionalidad en las características del semen de toros Bos taurus y Bos indicus pre y post congelación, con el fin de proporcionar mayor rentabilidad económica. A pesar de la reproducción vacuna no caracterizarse por la estacionalidad, estudios muestran la interferencia de las estaciones del año en la calidad del semen de toros El aumento de la temperatura ambiente puede conducir a elevada temperatura testicular, de las tasas metabólicas y de las exigencias de oxígeno, ocasionando alteraciones en la espermatogénesis y, por lo tanto, a un impacto negativo en la reproducción. Toros Bos indicus presentaron mejor rendimiento en la temporada más calurosa del año, presentando calidad de semen satisfactoria en comparación con toros Bos taurus. Esto es debido a mayor resistencia del ganado cebú a las altas temperaturas y la peroxidación de lípidos causada por el calor, que resulta en menor producción de especies reactivas al oxígeno y menos defectos en las células espermáticas. Así, toros de origen europea no presentan buen desempeño durante algunos períodos más calurosos del año, lo que lleva a cuestionar si la relación costo beneficio de aprovechamiento del semen para criopreservación justifica la tramitación del mismo por las Centrales de Recogida y Procesamiento de Semen en este periodo. Este hecho ha llevado a algunas empresas a suspender las actividades en ciertos meses del año.(AU)

Efeito do manejo e de variáveis bioclimáticas sobre a taxa de gestação em vacas receptoras de embriões / Effect of handling and environmental variables on the pregnancy rate of recipient cows

Para verificar o efeito do manejo e do ambiente sobre a taxa de gestação de receptoras bovinas cruzadas zebu x europeu (n=94) de embriões Nelore registraram-se o comportamento e variáveis clínicas e climáticas durante o protocolo de sincronização de cio e no dia da inovulação. Foi determinada a concentração de cortisol plasmático (n=36) no D0, D9 e D16 do protocolo e de progesterona (P4) no dia da inovulação. Não houve diferença significativa entre fêmeas gestantes (GEST) e não gestantes (nGEST) quanto ao estágio de maturação e classificação do embrião, pelagem, comportamento ou entre embriões descongelados e fresco. A concentração média de cortisol variou significativamente entre D0 e D16 (P>0,001). A P4 do D16 foi menor nas nGEST (P<0,01). O índice de temperatura de globo e umidade foi elevado, indicando que os animais poderiam estar sob estresse por calor. As fêmeas GEST apresentaram menoremperatura de pele (P<0,01). A análise de regressão mostrou aumento da probabilidade de prenhez de cerca de 25% entre o início e o final da tarde (P=0,08). A menor concentração plasmática de progesterona no momento da inovulação e a maior temperatura da pele demonstraram o desconforto térmico e influenciaram negativamente a fertilidade das receptoras de embriões. O estresse térmico por calor afetou a probabilidade de prenhez de vacas receptoras de embriões sob condições tropicais.

This work aimed to verify the effects of the handling and thermal environment on the pregnancy rate of embryo-recipient zebu x European cows (n=94) as well as the behavioral and clinical aspects at the moment of embryo transfer. Cortisol was analyzed by plasmatic samplers collected on D0, D9 and D16 of the hormonal treatment for estrous synchronization; blood was also sampled to analyze progesterone levels at the moment of embryo transfer. There was no difference (p>0.05) between pregnant and not pregnant females for maturation stage and embryo classification, coat, and reactivity between fresh and frozen embryos. The cortisol concentrations decreased (p>0.001) between D0 and D16, and the concentration of progesterone was similar in function of the pregnancy stage. Nevertheless progesterone in D16 for non pregnant cows was lower than for pregnant ones in the same day. Moreover, pregnant cows showed lower skin temperature. The values of Black Globe-Humidity Index were at very high limits, indicating that all animals could be under heat stress. The regression analysis indicated a tendency (p=0.08) to increase the pregnancy probability of 25% between the beginning and end of the afternoon. Thus, low plasmatic concentration of progesterone and high skin temperature represents a factor of thermal discomfort at the moment of the embryo receiving, influencing the pregnancy rate of recipient cows. As observed, heat stress decreased the probability of the pregnancy of recipient cows in tropical environment.

Bicarbonato, albumina s�rica bovina e heparina afetam a integridade do acrossomo do espermatozoide bovino p�s-descongela��o? / Bicarbonate, bovine serum albumin and heparin affect acrosomal integrity of bovine post-thawing?

O trabalho teve como objetivo avaliar o efeito do bicarbonato, albumina s�rica bovina e heparina sobre a integridade do acrossomo do espermatozoide bovino criopreservado, durante incuba��o in vitro. Doses comerciais de s�men de dez touros foram submetidas �s an�lises de motilidade, vigor, integridade da membrana plasm�tica (eosina/nigrosina-EN) e status acrossomal(trypan blue/Giemsa-TBG), nos momentos p�s-descongela��o, p�s-wash e p�s-incuba��o por 5 horas a 37�C. Ap�s a descongela��o e lavagem por centrifuga��o em solu��o salina 0,9% (wash),as doses foram fracionadas e submetidas aos seguintes tratamentos: Talp-sp (controle); Talp-sp sem bicarbonato; Talp-sp sem albumina s�rica bovina e; Talp-sp acrescido de heparina. Os dados foram submetidos � an�lise de vari�ncia e as m�dias comparadas pelo teste de Duncan. Todas as caracter�sticas esperm�ticas sofreram efeito do tempo de incuba��o, diferindo significativamente dos valores obtidos p�s-descongela��o. Houve efeito significativo de tratamento para rea��o acrossomal verdadeira, com os maiores percentuais nos tratamentos controle (2,72�0,40) e com heparina (2,31�0,44), sendo que este �ltimo n�o diferiu dos demais. Houve intera��o significativa entre os momentos de avalia��o e os tratamentos para a vari�vel rea��o do acrossomo verdadeira, com os maiores valores nos tratamentos controle e com heparina (4,65�0,79 e 4,30�0,94%, respectivamente), n�o havendo diferen�a entre si. De acordo com os resultados obtidos conclui-se que a presen�a do bicarbonato ou da albumina s�rica bovina no meio de cultivo, leva ao aumento de espermatozoides apresentando rea��o do acrossomo verdadeira

The aim of this work was to evaluate de effect of bicarbonate, bovine serum albumin and heparin on sperm acrosome integrity of bovine cryopreserved semen, during in vitro incubation.Commercial doses from ten bulls were submitted to analysis of motility, vigour, plasmatic membrane integrity (eosin/nigrosin � EN) and acrosomal status (trypan blue/Giemsa), after thawing, wash and 5 hours incubation at 37�C. After thawing and washing by centrifugation with saline solution at 0.9%, doses were fractionated and submitted to following treatments:Talp-sp (control); Talp-sp bicarbonate free; Talp-sp bovine serum albumin free and; Talp-sp plus heparin. Data were submitted to ANOVA and means were compared by Duncan�s test. All sperm characteristics changed along incubation time with values differing significantly from those observed after thawing. Treatment had significant effect on the percentage of true acrosome reaction with the highest values being observed in control (2.72�0.40) and heparin(2.31�0.44) groups, this last being equal to the others. There was significant interaction between moments and treatments for true acrosome reaction variable with the highest values being observed in control and heparin groups (4.65�0.79 and 4.30�0.94%, respectively), although none difference had been found between these values. These results indicate that the presence of bicarbonate or bovine serum albumin in culture medium enhance the number of spermatozoa showing true acrosome reaction

Efeito do manejo e de variáveis bioclimáticas sobre a taxa de gestação em vacas receptoras de embriões / Effect of handling and environmental variables on the pregnancy rate of recipient cows

Para verificar o efeito do manejo e do ambiente sobre a taxa de gestação de receptoras bovinas cruzadas zebu x europeu (n=94) de embriões Nelore registraram-se o comportamento e variáveis clínicas e climáticas durante o protocolo de sincronização de cio e no dia da inovulação. Foi determinada a concentração de cortisol plasmático (n=36) no D0, D9 e D16 do protocolo e de progesterona (P4) no dia da inovulação. Não houve diferença significativa entre fêmeas gestantes (GEST) e não gestantes (nGEST) quanto ao estágio de maturação e classificação do embrião, pelagem, comportamento ou entre embriões descongelados e fresco. A concentração média de cortisol variou significativamente entre D0 e D16 (P>0,001). A P4 do D16 foi menor nas nGEST (P<0,01). O índice de temperatura de globo e umidade foi elevado, indicando que os animais poderiam estar sob estresse por calor. As fêmeas GEST apresentaram menoremperatura de pele (P<0,01). A análise de regressão mostrou aumento da probabilidade de prenhez de cerca de 25% entre o início e o final da tarde (P=0,08). A menor concentração plasmática de progesterona no momento da inovulação e a maior temperatura da pele demonstraram o desconforto térmico e influenciaram negativamente a fertilidade das receptoras de embriões. O estresse térmico por calor afetou a probabilidade de prenhez de vacas receptoras de embriões sob condições tropicais.(AU)

This work aimed to verify the effects of the handling and thermal environment on the pregnancy rate of embryo-recipient zebu x European cows (n=94) as well as the behavioral and clinical aspects at the moment of embryo transfer. Cortisol was analyzed by plasmatic samplers collected on D0, D9 and D16 of the hormonal treatment for estrous synchronization; blood was also sampled to analyze progesterone levels at the moment of embryo transfer. There was no difference (p>0.05) between pregnant and not pregnant females for maturation stage and embryo classification, coat, and reactivity between fresh and frozen embryos. The cortisol concentrations decreased (p>0.001) between D0 and D16, and the concentration of progesterone was similar in function of the pregnancy stage. Nevertheless progesterone in D16 for non pregnant cows was lower than for pregnant ones in the same day. Moreover, pregnant cows showed lower skin temperature. The values of Black Globe-Humidity Index were at very high limits, indicating that all animals could be under heat stress. The regression analysis indicated a tendency (p=0.08) to increase the pregnancy probability of 25% between the beginning and end of the afternoon. Thus, low plasmatic concentration of progesterone and high skin temperature represents a factor of thermal discomfort at the moment of the embryo receiving, influencing the pregnancy rate of recipient cows. As observed, heat stress decreased the probability of the pregnancy of recipient cows in tropical environment.(AU)

Bicarbonato, albumina s�rica bovina e heparina afetam a integridade do acrossomo do espermatozoide bovino p�s-descongela��o? / Bicarbonate, bovine serum albumin and heparin affect acrosomal integrity of bovine post-thawing?

O trabalho teve como objetivo avaliar o efeito do bicarbonato, albumina s�rica bovina e heparina sobre a integridade do acrossomo do espermatozoide bovino criopreservado, durante incuba��o in vitro. Doses comerciais de s�men de dez touros foram submetidas �s an�lises de motilidade, vigor, integridade da membrana plasm�tica (eosina/nigrosina-EN) e status acrossomal(trypan blue/Giemsa-TBG), nos momentos p�s-descongela��o, p�s-wash e p�s-incuba��o por 5 horas a 37�C. Ap�s a descongela��o e lavagem por centrifuga��o em solu��o salina 0,9% (wash),as doses foram fracionadas e submetidas aos seguintes tratamentos: Talp-sp (controle); Talp-sp sem bicarbonato; Talp-sp sem albumina s�rica bovina e; Talp-sp acrescido de heparina. Os dados foram submetidos � an�lise de vari�ncia e as m�dias comparadas pelo teste de Duncan. Todas as caracter�sticas esperm�ticas sofreram efeito do tempo de incuba��o, diferindo significativamente dos valores obtidos p�s-descongela��o. Houve efeito significativo de tratamento para rea��o acrossomal verdadeira, com os maiores percentuais nos tratamentos controle (2,72�0,40) e com heparina (2,31�0,44), sendo que este �ltimo n�o diferiu dos demais. Houve intera��o significativa entre os momentos de avalia��o e os tratamentos para a vari�vel rea��o do acrossomo verdadeira, com os maiores valores nos tratamentos controle e com heparina (4,65�0,79 e 4,30�0,94%, respectivamente), n�o havendo diferen�a entre si. De acordo com os resultados obtidos conclui-se que a presen�a do bicarbonato ou da albumina s�rica bovina no meio de cultivo, leva ao aumento de espermatozoides apresentando rea��o do acrossomo verdadeira(AU)

The aim of this work was to evaluate de effect of bicarbonate, bovine serum albumin and heparin on sperm acrosome integrity of bovine cryopreserved semen, during in vitro incubation.Commercial doses from ten bulls were submitted to analysis of motility, vigour, plasmatic membrane integrity (eosin/nigrosin � EN) and acrosomal status (trypan blue/Giemsa), after thawing, wash and 5 hours incubation at 37�C. After thawing and washing by centrifugation with saline solution at 0.9%, doses were fractionated and submitted to following treatments:Talp-sp (control); Talp-sp bicarbonate free; Talp-sp bovine serum albumin free and; Talp-sp plus heparin. Data were submitted to ANOVA and means were compared by Duncan�s test. All sperm characteristics changed along incubation time with values differing significantly from those observed after thawing. Treatment had significant effect on the percentage of true acrosome reaction with the highest values being observed in control (2.72�0.40) and heparin(2.31�0.44) groups, this last being equal to the others. There was significant interaction between moments and treatments for true acrosome reaction variable with the highest values being observed in control and heparin groups (4.65�0.79 and 4.30�0.94%, respectively), although none difference had been found between these values. These results indicate that the presence of bicarbonate or bovine serum albumin in culture medium enhance the number of spermatozoa showing true acrosome reaction(AU)

Effect of oleic-linoleic acid and beta-sitosterol to freezing extender of bulls and stallions semen / Efeito da adição de ácido oleico-linoleico e beta-sitosterol ao diluente de congelação do sêmen de touros e garanhões

Addition of polyunsaturated fatty acids and/or cholesterol to a freezing diluent can modify the sperm plasma membrane composition, influencing its behavior during cryopreservation, thus, favoring seminal cryoresistance. The present study aimed to evaluate the effects of the addition of oleic-linoleic acid, (OLA); beta-sitosterol (beta-sit), a plant analog of cholesterol; and OLA + beta-sit in combination to a freezing diluent, on the cryopreservation bull and stallion semen. The following variables were analyzed: motility/vigor, plasma and acrosomal membrane integrity (by Trypan Blue/Giemsa staining), mitochondrial activity (by DAB staining), and lipid peroxidation (by a TBARS assays). The lipids were added according to experimental treatments: C control group, A1 and A2 OLA at concentrations of 37 uM and 74 uM, B1 and B2 beta-sit at concentrations of 1 ug mL-1 and 2 ug mL-1; AB1 and AB2 OLA 37 uM + beta-sit 1 g mL-1 and OLA 74 uM + beta-sit 2 ug mL-1, respectively. The study was divided into three experiments; in Experiment 1, the concentrations of the groups A1, B1, and AB1 were evaluated, whereas in Experiment 2 the concentrations of the groups A2, B2, and AB2 were analyzed, both experiments were performed with bull semen. We conducted Experiment 3 using equine semen with the addition of lipids at all of the concentrations described. Data were subjected to analysis of variance, using the GLM procedure of SAS, with treatment means compared by Duncan test considering 5% significance. These variables differed significantly after thawing the semen post-collection. However, there was no significant difference between treatments when variables were compared within the same time point, except for Experiment 2, where there was a decrease in motility and vigor decrease post-thaw in the groups following β-sit addition (C – 51.0 ± 13.7%/2.9 ± 0.4; B2 – 35.8 ± 15.8%/2.3 ± 0.6; AB2 – 38.5 ± 16.6%/2.5 ± 0.5, respectively; p < 0.05).

A adição de ácidos graxos poli-insaturados e/ou colesterol ao diluidor pode modificar a composição da membrana plasmática do espermatozoide, influenciando seu comportamento frente à criopreservação e favorecendo, assim, a crioresistência seminal. O presente trabalho teve como objetivo avaliar o efeito da adição do ácido oleico-linoleico (AOL), beta-sitosterol (beta-sit), um análogo vegetal do colesterol, e da associação AOL + beta-sit, ao diluente de congelação de sêmen bovino e equino. As variáveis analisadas foram motilidade/ vigor, integridade das membranas plasmática e acrossomais (Trypan Blue/Giemsa), atividade mitocondrial (DAB) e nível de peroxidação lipídica (TBARS). Os lipídios foram adicionados de acordo com os tratamentos experimentais: C grupo controle; A1 e A2 AOL nas concentrações de 37 uM e 74 uM; B1 e B2 beta-sit nas concentrações de 1 ug ml-1 e 2 ug ml-1; AB1 e AB2 AOL 37 uM + beta-sit 1 ug ml-1 e AOL 74 uM + beta-sit 2 ug ml-1, respectivamente. O trabalho consistiu de três experimentos, sendo que o Experimento 1 testou as concentrações dos grupos A1, B1 e AB1, e o Experimento 2 as concentrações dos grupos A2, B2 e AB2, ambos utilizando sêmen de touro. Para o Experimento 3 utilizou-se sêmen equino, sendo a adição dos lipídios feita em todas a concentrações descritas. Os dados foram submetidos à análise de variância, através do procedimento GLM do SAS, sendo as médias dos tratamentos comparadas pelo teste de Duncan em nível de 5% de significância. Os valores das variáveis avaliadas pós-descongelação diferiram significativamente daqueles obtidos pós-colheita, porém não foi observada diferença significativa entre os tratamentos quando as variáveis foram comparadas dentro do mesmo momento, exceto no Experimento 2, em que os valores de motilidade / vigor pós-descongelação nos grupos acrescidos do β-sit foram menores que os do controle (C – 51,0 ± 13,7% / 2,9 ± 0,4; B2 – 35,8 ± 15,8% / 2,3 ± 0,6; AB2 – 38,5 ± 16,6% / 2,5 ± 0,5, respectivamente; p < 0,05).