O uso do Eugenol na criopreservação do sêmen bovino / The use of Eugenol in the cryopreservation of bovine sêmen

O experimento foi conduzido com o objetivou de avaliar os efeitos antioxidantes da adição do eugenol no diluidor TRIS-gema para a criopreservação de espermatozoides bovino. Foram utilizados vinte ejaculados de quatro bovinos Curraleiro Pé-Duro, após as coletas o sêmen foi diluído em TRIS-Gema e dividido em três alíquotas; contole, tratamento nas concentrações de 10µM e 50µM de eugenol. Posteriormente as amostras foram envasadas em palhetas de 0,25ml e criopreservadas. Em seguida as palhetas foram mantidas em equilíbrio por 60 minutos a 5ºC, para então serem criopreservadas em protocolo padrão de criopreservação com uso da máquina TK 3000®, e por fim as palhetas foram mergulhadas em nitrogênio líquido (-196º C) e armazenadas em botijão criogênico. Após 30 dias foram realizadas as análises pós-criopreservação. As avaliações espermáticas incluíram motilidade e vigor espermático (TTR), nos tempos de 0, 60, 120 e 180 minutos, determinação da integridade das membranas plasmática e acrossomal, funcionalidade da membrana espermática (HOST), cinética espermática, quantificação da lipoperoxidação espermática, quantificação de GSH e teste de fertilização in vitro. Observou-se que a suplementação de eugenol nas concentrações de 50µM diferiu significativamente (P <0,05) dos demais tratamentos, induzindo um aumento na quantificação de GSH, uma redução na determinação de MDA, um aumento no VSL e preservou a integridade das membranas plasmática e acrossomal. Em conclusão, é sugerida a utilização do eugenol na criopreservação do sêmen de touros, a fim de limitar os danos induzidos pelo frio

Equine Rabies in the Southern Region of Piauí State

Background: Rabies is an infectious disease that is important in the "One Health" worldwide with high lethality rate. The etiological agent is a neurotropic virus, genus Lyssavirus, transmitted mainly through the saliva of infected animals. For equines, the bite of hematophagous bats is the main source of infection. Piauí is an important state for equestrian sports and the increase in the number of horses with neurological clinical signs without diagnosis has increased in recent years. In this context, the aim of this study is to report to the scientific community a confirmed case of equine rabies in the Santa Luz county, Southernmost state of Piauí, Brazil.Case: A 3-year-old female non-defined breed horse, was admitted to the Hospital Veterinário da Universidade Federal do Piauí (UFPI/CPCE). The equine had difficulty walking 2 days ago, in the panoramic inspection was restless and disoriented in the paddock. Rectal temperature of 38.2oC, heart rate of 60 bpm, respiratory rate of 40 mpm, congested mucosa and dyspnea were verified. With the progression of the neurological signals, it positioned itself in a lateral decubitus with pedaling movements, hyperesthesia, dysphagia and paralysis of the hindlimbs. The clinical suspicion was rabies and the Agência de Defesa Agropecuária do Piauí (ADAPI) was communicated to euthanize the animal and collect samples for diagnosis in accordance with official standards of the Ministério da Agricultura, Pecuária e Abastecimento (MAPA). At necropsy, there was slight brain hyperemia, with no other significant organ changes. Fragments of the cerebellum, cortex, hippocampus and spinal cord were collected and sent at a temperature of 4oC to perform the Direct Immunofluorescence (DIF) assay. Samples for histopathology were not collected because they do not include assay for confirmatory diagnosis of rabies. The DIF technique with antigen-labeled antibodies were performed in the imprint lamina of these fragments. The fragments were treated according to specific protocol. The results were negative for DIF in the collected equine fragments. For complementary exam, the samples were homogenized, clarified and inoculated intracranial in BALB/C mice, being observed for up to 30 days. The samples were positive after the bioassay.Discussion: Piauí is a state with great equestrian activity that expose the animals to the risks of transmission of infectious diseases. Among these diseases, rabies is important for affecting horses, but also humans (veterinarians and owners). In the present report, the equine showed clinical signs of furious rabies for a short period, rapidly evolving to paralytic form. This clinical aspect must be carefully evaluated by the veterinarian, in order to avoid false clinical suspicions such as tetanus or other non-infectious diseases. The official diagnosis of the rabies is DIF technique, with high sensitive (80-100%). According to the results of the DIF technique, it was possible to confirm the clinical suspicion of rabies in mice previously inoculated with emulsion of fragments of the equine central nervous system (CNS). This fact demonstrates that in negative results for CNS samples from the horse, the bioassay increases the sensitivity of the test and avoids false negative diagnoses. Thus, it was possible to prove that rabies is affecting the equines in the southern region of Piauí state and alerts the breeders and the community to intensify surveillance and control of the hematophagous bats. For the authors, this is the first scientific report of rabies in the region studied

ANÁLISES DE MEMBRANA PLASMÁTICA, ACROSSOMA E MITOCÔNDRIA DE ESPERMATOZOIDE OVINO APÓS CRIOPRESERVAÇÃO COM ADIÇÃO DO ÁCIDO FÓLICO NO MEIO TRIS-GEMA

Folic acid is closely linked to cobalamin, which is a carrier of hydroxymethyl and ant groups. The objective of this work was to evaluate the effect of adding folic acid to the TRIS-yolk diluter and possible effect on the membrane, mitochondria and acrosome of sheep sperm after thawing the semen. There were six sheep and seven collections of each animal in sessions between 48 and 72 hours. After collection and analysis, the semen samples were mixed and submitted to the formation of a pool. Diluted in TRIS-yolk medium, and divided into 3 groups; Group control; Group 2: 10,000 µM of folic acid and in Group 3: 5000 µM of folic acid. Subsequently, the semen samples were packaged in 0.25 mL straws and processed in a semen freezing machine. After a few days, the semen was thawed and evaluated: plasma membrane integrity, acrosome function and integrity. They were analyzed using an analysis of variance (ANOVA) followed by the Newman-Keuls test, using SAS. The addition of a micronutrient with potential antioxidant action in the semen indicates that it can reduce the action of free radicals that alter the plasma membrane and sperm DNA. The evaluation of the plasma membrane integrity, mitochondrial activity and the acrosome integrity of post-thawed sperm were not significantly different between the groups evaluated. Thus, it is concluded that the addition of folic acid in concentrations of 5000 µM and 10000 µM to the TRIS-yolk seminal diluter does not significantly influence the variables evaluated in this experiment.O ácido fólico está intimamente ligado à cobalamina, que é um transportador de grupos hidroximetil e formiga. O objetivo deste trabalho foi avaliar o efeito da adição de ácido fólico ao diluidor TRIS-gema e possível efeito sobre a membrana, mitocôndrias e acrossoma de espermatozoides ovinos após descongelamento do sêmen. Foram seis ovinos e sete coletas de cada animal em sessões entre 48 e 72 horas. Após coleta e análise, as amostras de sêmen foram misturadas e submetidas à formação de um pool. Diluído em meio TRIS-gema, e dividido em 3 grupos; Controle de grupo; Grupo 2: 10.000 µM de ácido fólico e no Grupo 3: 5.000 µM de ácido fólico. Posteriormente, as amostras de sêmen foram acondicionadas em palhetas de 0,25 mL e processadas em máquina de congelamento de sêmen. Após alguns dias, o sêmen foi descongelado e avaliado: integridade da membrana plasmática, função acrossômica e integridade. Eles foram analisados por meio de análise de variância (ANOVA) seguida do teste de Newman-Keuls, usando o SAS. A adição de um micronutriente com potencial ação antioxidante no sêmen indica que pode reduzir a ação de radicais livres que alteram a membrana plasmática e o DNA espermático. A avaliação da integridade da membrana plasmática, atividade mitocondrial e integridade acrossômica dos espermatozóides pós-descongelados não foram significativamente diferentes entre os grupos avaliados. Assim, conclui-se que a adição de ácido fólico nas concentrações de 5000 µM e 10000 µM ao diluidor seminal TRIS-gema não influencia significativamente nas variáveis avaliadas neste experimento

INFLUÊNCIA DE UM ÁCIDO GRAXO ADICIONADO AO DILUENTE SEMINAL SOBRE A INTEGRIDADE DA MEMBRANA PLASMÁTICA DE ESPERMATOZOIDES CAPRINOS CRIOPRESERVADOS

The objective of this study was to evaluate the antioxidant effects of supplementing different concentrations (0.5μM, 5μM and 50μM) of polyunsaturated fatty acid, arachidonic acid to the TRIS-yolk diluter on the integrity of the plasma membrane during the cryopreservation of goat sperm. For this purpose, four Anglo-nubian goats were used, in which five samples / animal were collected, using artificial vagina. After evaluating the swirling and motility of the ejaculates, the pool was made, then diluted in TRIS-Gem and divided according to the treatments. After processing, the samples were packaged in 0.25mL straws and cryopreserved using the TK 3000® machine. Defrosting occurred after at least 5 days of storage in a cryogenic cylinder. Then, the integrity of the plasma membrane of goat sperm post cryopreservation was carried out, using the double staining method, where carboxyfluorescein diacetate (DCF) and propidium iodide (IP) were used. The data were analyzed and the results of the researched variable were subjected to analysis of variance (ANOVA) using the general linear models procedure (Proc GLM) and the Duncan test was used to compare the means, with a 5% probability. The analyzes were performed using the Statistical Analysis System program (SAS Institute Inc, 2013). After analysis, it was observed that the control group had the best percentage, and differed significantly (p<0.05) from the treatment with 50μM of arachidonic acid. It was concluded that the 50μM arachidonic acid concentration is not effective to maintain the integrity of the plasma membrane, and to minimize the oxidative stress of cryopreservation.O objetivo deste estudo foi avaliar os efeitos antioxidantes da suplementação de diferentes concentrações (0,5μM, 5μM e 50μM) de ácido graxo poliinsaturado, ácido araquidônico ao diluidor TRIS-gema sobre a integridade da membrana plasmática durante a criopreservação de sêmen caprino. Para tanto, foram utilizadas quatro cabras anglo-núbias, nas quais foram coletadas cinco amostras/animal, utilizando vagina artificial. Após avaliar o turbilhão e a motilidade dos ejaculados, foi feito o pool, diluído em TRIS-Gem e dividido de acordo com os tratamentos. Após o processamento, as amostras foram acondicionadas em palhetas de 0,25mL e criopreservadas em máquina TK 3000®. O degelo ocorreu após pelo menos 5 dias de armazenamento em cilindro criogênico. Em seguida, foi realizada a integridade da membrana plasmática de espermatozoides caprinos pós-criopreservação, utilizando o método de dupla coloração, onde foram utilizados diacetato de carboxifluoresceína (DCF) e iodeto de propídio (IP). Os dados foram analisados e os resultados da variável pesquisada foram submetidos à análise de variância (ANOVA) pelo procedimento de modelos lineares gerais (Proc GLM) e para comparação de médias foi utilizado o teste de Duncan, com probabilidade de 5%. As análises foram realizadas por meio do programa Statistical Analysis System (SAS Institute Inc, 2013). Após análise, observou-se que o grupo controle apresentou a melhor porcentagem, diferindo significativamente (p<0,05) do tratamento com 50μM de ácido araquidônico. Concluiu-se que a concentração de 50μM de ácido araquidônico não é eficaz para manter a integridade da membrana plasmática e minimizar o estresse oxidativo da criopreservação

ANÁLISES DE MEMBRANA PLASMÁTICA, ACROSSOMA E MITOCÔNDRIA DE ESPERMATOZOIDES OVINO APÓS CRIOPRESERVAÇÃO COM ADIÇÃO DO ÁCIDO FÓLICO NO MEIO TRIS-GEMA

Folic acid is closely linked to cobalamin, which is a carrier of hydroxymethyl and ant groups. The objective of this work was to evaluate the effect of adding folic acid to the TRIS-yolk diluter and possible effect on the membrane, mitochondria and acrosome of sheep sperm after thawing the semen. There were six sheep and seven collections of each animal in sessions between 48 and 72 hours. After collection and analysis, the semen samples were mixed and submitted to the formation of a pool. Diluted in TRIS-yolk medium and divided into 3 groups; Group control; Group 2: 10,000µM of folic acid and in Group 3: 5000µM of folic acid. Subsequently, the semen samples were packaged in 0.25mL straws and processed in a semen freezing machine. After a few days, the semen was thawed and evaluated: plasma membrane integrity, acrosome function and integrity. They were analyzed using an analysis of variance (ANOVA) followed by the Newman-Keuls test, using SAS. The addition of a micronutrient with potential antioxidant action in the semen indicates that it can reduce the action of free radicals that alter the plasma membrane and sperm DNA. The evaluation of the plasma membrane integrity, mitochondrial activity and the acrosome integrity of post-thawed sperm were not significantly different between the groups evaluated. Thus, it is concluded that the addition of folic acid in concentrations of 5000µM and 10000µM to the TRIS-yolk seminal diluter does not significantly influence the variables evaluated in this experiment.O ácido fólico está intimamente ligado à cobalamina, que é um transportador de grupos hidroximetil e formiga. O objetivo deste trabalho foi avaliar o efeito da adição de ácido fólico ao diluidor TRIS-gema e possível efeito sobre a membrana, mitocôndrias e acrossoma de espermatozoides ovinos após descongelamento do sêmen. Foram seis ovinos e sete coletas de cada animal em sessões entre 48 e 72 horas. Após coleta e análise, as amostras de sêmen foram misturadas e submetidas à formação de um pool. Diluído em meio TRIS-gema e dividido em 3 grupos; Controle de grupo; Grupo 2: 10.000µM de ácido fólico e no Grupo 3: 5.000µM de ácido fólico. Posteriormente, as amostras de sêmen foram acondicionadas em palhetas de 0,25mL e processadas em máquina de congelamento de sêmen. Após alguns dias, o sêmen foi descongelado e avaliado: integridade da membrana plasmática, função acrossômica e integridade. Eles foram analisados por meio de análise de variância (ANOVA) seguida do teste de Newman-Keuls, usando o SAS. A adição de um micronutriente com potencial ação antioxidante no sêmen indica que pode reduzir a ação de radicais livres que alteram a membrana plasmática e o DNA espermático. A avaliação da integridade da membrana plasmática, atividade mitocondrial e integridade acrossômica dos espermatozóides pós-descongelados não foram significativamente diferentes entre os grupos avaliados. Assim, conclui-se que a adição de ácido fólico nas concentrações de 5000µM e 10000µM ao diluidor seminal TRIS-gema não influencia significativamente nas variáveis avaliadas neste experimento

SUPLEMENTAÇÃO DO ÁCIDO OLEICO NO DILENTE SEMINAL SOBRE O POTENCIAL MITOCONDRIAL DE ESPERMATOZOIDES CAPRINOS CRIOPRESERVADOS

The research aimed to evaluate the antioxidant effect of supplementation of 0.5μM, 5μM and 50μM of oleic acid to the TRIS-yolk extender on the mitochondrial potential (MIT) during the cryopreservation of goat sperm. For that, four Anglo-nubian goats were used, in which five samples / animal were collected, using artificial vagina. After evaluating the swirling and motility of the ejaculates, the pool was made, then diluted in TRIS-Gem and divided according to the treatments. After processing, the samples were packaged in 0.25mL straws and cryopreserved using the TK 3000® machine. After a minimum of 5 days of storage in a cryogenic cylinder, thawing was performed to assess the MIT of goat sperm after cryopreservation, using the lipophilic cationic fluorochrome JC-1. The data were submitted to analysis of variance (ANOVA), using the general linear models procedure (Proc GLM), and the Duncan test was used to compare the averages, with a 5% probability. The analyzes were performed using the Statistical Analysis System program (SAS Institute Inc, 2013). Thus, it was observed that the concentrations of 0.5μM and 5μM of oleic acid maintained the mitochondrial potential similar to the control, differing (p<0.05) only the concentration of 50μM. It can be concluded that 0.5μM and 5μM oleic acid are able to maintain the mitochondrial potential, prolonging the viability of cryopreserved goat sperm.A pesquisa teve como objetivo avaliar o efeito antioxidante da suplementação de 0,5μM, 5μM e 50μM de ácido oleico ao diluidor TRIS-gema sobre o potencial mitocondrial (MIT) durante a criopreservação de sêmen caprino. Para tanto, foram utilizadas quatro cabras anglo-núbias, nas quais foram coletadas cinco amostras/animal, utilizando vagina artificial. Após avaliar o turbilhão e a motilidade dos ejaculados, foi feito o pool, diluído em TRIS-Gem e dividido de acordo com os tratamentos. Após o processamento, as amostras foram acondicionadas em palhetas de 0,25mL e criopreservadas em máquina TK 3000®. Após um período mínimo de 5 dias de armazenamento em cilindro criogênico, foi realizado o descongelamento para avaliação do MIT do sêmen caprino após a criopreservação, utilizando o fluorocromo catiônico lipofílico JC-1. Os dados foram submetidos à análise de variância (ANOVA), utilizando-se o procedimento de modelos lineares gerais (Proc GLM), e o teste de Duncan foi utilizado para comparar as médias, com probabilidade de 5%. As análises foram realizadas por meio do programa Statistical Analysis System (SAS Institute Inc, 2013). Assim, observou-se que as concentrações de 0,5μM e 5μM de ácido oleico mantiveram o potencial mitocondrial semelhante ao controle, diferindo (p<0,05) apenas da concentração de 50μM. Pode-se concluir que 0,5μM e 5μM de ácido oleico são capazes de manter o potencial mitocondrial, prolongando a viabilidade do esperma caprino criopreservado

Phylogenetic analysis of rabies surveillance samples from north and northeast Brazil

Viruses of the Lyssavirus genus are classified into several genotypes (GT1 to GT7), of which only GT1 (classic rabies virus—RABV) has a cosmopolitan distribution and circulates in Brazil. GT1 is subdivided into several antigenic variants (AgV) maintained in independent cycles with a narrow host range and distinct geographic distributions, namely, AgV1 and AgV2 found in dogs, AgV3 in the vampire bats Desmodus rotundus, and AgV4 and AgV6 in bats non-hematophagous Tadarida brasiliensis and Lasiurus cinereus, a common variant of marmoset (Callithrix jacchus), and crab-eating fox (Cerdocyon thous). In this study, we performed phylogenetic analysis to identify at the antigenic variant level; six RABV genomes derived from the Rabies Surveillance in the north and northeast regions of Brazil. The analysis resulted in the formation of 11 monophyletic clusters, each corresponding to a particular variant, with high bootstrap support values. The samples were positioned inside the AgV3, AgV6, and Callithrix variant clades. This is the first report of the AgV6 variant found in northern Brazil, which provides valuable information for rabies surveillance in the country. The possibility of viral spillover has been much debated, as it deals with the risk of shifting transmission from a primary to a secondary host. However, more genomic surveillance studies should be performed, with a greater number and diversity of samples to better understand the transmission dynamics of each variant to detect changes in its geographic distribution and spillover events

Effect of Addition Palmitic Acid and Vitamin E to the Tris-Egg Yolk Diluter in Canine Semen Cryopreservation

Background: Canine sperm is a very delicate cell that is quite susceptible to oxidative stress since the cytoplasm is restricted and features little antioxidant reserves. Furthermore, the sperm membrane has some polyunsaturated fatty acids sensitive to lipid peroxidation, which makes it important to addition antioxidant substances to the diluter aiming at decreasing such stress to the sperm cell, particularly during seminal cryopreservation. Several antioxidants have been used in this process in some domestic animal’s species, however, the use of palmitic acid has been little reported in works on cryopreservation of semen of the canine species. Hence, this study aimed to assess the effect of addition antioxidants palmitic acid and vitamin E to the Tris-egg yolk diluter on the semen quality of dogs after thawing.Materials, Methods & Results: Samples were collected from the ejaculates of 4 adult dogs, apparently healthy, of the American Pit Bull Terrier breed of kennels in the city of Teresina, PI, places where the pre-freezing procedures of the dog’s semen were performed. The samples were diluted in Tris citric acid fructose (3.28 g Tris-hydroxymethyl-aminomethane, 1.78 g citric acid monohydrate and 1.25 g D-fructose), dissolved in 100 mL distilled water, and added 20% egg yolk and 6% glycerol, at the concentration of 100x106 sptz/mL. The semen samples were divided into 3 mL aliquots to form 3 experimental groups: G1 - Only Tris-egg yolk (Control group); G2 - Tris-egg yolk + 100 µM palmitic acid; and G3 - Tris-egg yolk + 116 µM vitamin E. Semen was collected weekly over a period of little over 2 months. After thawing, thermorresistance test (TTR) was carried out at 0, 30, 60, and 90 min to assess spermatics motility and vigor, in addition to analysis of integrity of plasma membrane, acrosomal membrane and mitochondrial activity of the sperm, using fluorescent probes. These assessments were performed out at the Animal Reproduction Biotechnology Laboratory (LBRA/UFPI). In the TTR, G2 and G3 didn´t exhibit significant results for spermatics motility or vigor when compared with the control group. The palmitic acid and vitamin E also had no significant effects on the parameters of acrosomal membrane integrity or mitochondrial activity. However, sperm cryopreserved with the addition of palmitic acid exhibited significant differences for plasma membrane integrity, providing greater protection to the sperm cells in G2.Discussion: The palmitic acid is one of the most saturated fatty acids in human semen, with reports of great proportions also in the seminal plasma of dogs. Its main role is to protect the plasma membrane from external damage, improving viability and fertility of the sperm after cryopreservation. Data is scarce in the literature on the composition of fatty acids in canine semen and regarding the use of palmitic acid as a seminal antioxidant in that species, which grants further studies aiming to investigate such valuable information for canine reproduction. It is concluded that addition palmitic acid at 100 µM concentration to the Tris-egg yolk diluter was able to preserve the integrity of the plasma membrane during the process of cryopreservation of canine semen.Keywords: dog, semen, antioxidants, cryopreservation.Descritores: cão, sêmen, antioxidantes, criopreservação

Effect of Addition Palmitic Acid and Vitamin E to the Tris-Egg Yolk Diluter in Canine Semen Cryopreservation

Background: Canine sperm is a very delicate cell that is quite susceptible to oxidative stress since the cytoplasm is restricted and features little antioxidant reserves. Furthermore, the sperm membrane has some polyunsaturated fatty acids sensitive to lipid peroxidation, which makes it important to addition antioxidant substances to the diluter aiming at decreasing such stress to the sperm cell, particularly during seminal cryopreservation. Several antioxidants have been used in this process in some domestic animal’s species, however, the use of palmitic acid has been little reported in works on cryopreservation of semen of the canine species. Hence, this study aimed to assess the effect of addition antioxidants palmitic acid and vitamin E to the Tris-egg yolk diluter on the semen quality of dogs after thawing.Materials, Methods & Results: Samples were collected from the ejaculates of 4 adult dogs, apparently healthy, of the American Pit Bull Terrier breed of kennels in the city of Teresina, PI, places where the pre-freezing procedures of the dog’s semen were performed. The samples were diluted in Tris citric acid fructose (3.28 g Tris-hydroxymethyl-aminomethane, 1.78 g citric acid monohydrate and 1.25 g D-fructose), dissolved in 100 mL distilled water, and added 20% egg yolk and 6% glycerol, at the concentration of 100x106 sptz/mL. The semen samples were divided into 3 mL aliquots to form 3 experimental groups: G1 - Only Tris-egg yolk (Control group); G2 - Tris-egg yolk + 100 µM palmitic acid; and G3 - Tris-egg yolk + 116 µM vitamin E. Semen was collected weekly over a period of little over 2 months. After thawing, thermorresistance test (TTR) was carried out at 0, 30, 60, and 90 min to assess spermatics motility and vigor, in addition to analysis of integrity of plasma membrane, acrosomal membrane and mitochondrial activity of the sperm, using fluorescent probes. These assessments were performed out at the Animal Reproduction Biotechnology Laboratory (LBRA/UFPI). In the TTR, G2 and G3 didn´t exhibit significant results for spermatics motility or vigor when compared with the control group. The palmitic acid and vitamin E also had no significant effects on the parameters of acrosomal membrane integrity or mitochondrial activity. However, sperm cryopreserved with the addition of palmitic acid exhibited significant differences for plasma membrane integrity, providing greater protection to the sperm cells in G2.Discussion: The palmitic acid is one of the most saturated fatty acids in human semen, with reports of great proportions also in the seminal plasma of dogs. Its main role is to protect the plasma membrane from external damage, improving viability and fertility of the sperm after cryopreservation. Data is scarce in the literature on the composition of fatty acids in canine semen and regarding the use of palmitic acid as a seminal antioxidant in that species, which grants further studies aiming to investigate such valuable information for canine reproduction. It is concluded that addition palmitic acid at 100 µM concentration to the Tris-egg yolk diluter was able to preserve the integrity of the plasma membrane during the process of cryopreservation of canine semen.Keywords: dog, semen, antioxidants, cryopreservation.Descritores: cão, sêmen, antioxidantes, criopreservação

EFICIÊNCIA DOS DILUIDORES TRIS E BOTU-CRIO® SOBRE OS PARÂMETROS SEMINAIS DE GARANHÕES DAS RAÇAS QUARTO DE MILHA E MANGALARGA MARCHADOR

The limiting factor in the cryopreservation process of equine semen is related to the species, as they present a great variability in the ejaculate’s characteristics after thawing. The aim of this study was to evaluate sperm viability after thawing, from Quarter Horse and Mangalarga Marchador stallions using two extenders (Botu-crio and Tris) in cryopreservation. To this end, we analyzed the physical characteristics of fresh semen, the sperm membrane functionality by the hypoosmotic swelling test (HOST), total motility and vigor by the Thermoresistance Test (TRT), progressive motility by a computerized system CASA (Computer-Assisted Semen Anlyses) and acrosomal membrane integrity and functionality of the mitochondria by epifluorescence microscopy. After thawing, the extender Botu-crio® better preserved motility, vigor and integrity of the plasma membrane. There was no significant difference between breeds for the thermoresistance test after twaing. Quarter Horse showed higher percentage of bigger defects in the sperm pathology analysis