Relação entre a capacitação espermática e a fertilidade de sêmen criopreservado de bovinos / Relationship between sperm capacitation and fertility in bovine cryopreserved semen

A qualidade do sêmen criopreservado, utilizado na inseminação artificial em tempo fixo (IATF) em bovinos, é um dos principais fatores que impactam sobre a fertilidade, e está relacionada à capacidade de produção espermática dos touros, à criotolerância dos espermatozoides e aos critérios técnicos do processo de criopreservação adotados. Neste sentido, devemos destacar a importância do controle de qualidade das partidas de sêmen antes de serem liberadas para uso na IATF. Nos últimos anos várias técnicas vêm sendo desenvolvidas para avaliar com mais acurácia as partidas de sêmen e evitar o uso daquelas que possam resultar em prejuízos na fertilidade, mas mesmo assim, tem se notado alta variabilidade na taxa de prenhez entre touros e entre partidas de sêmen. Esta divergência se deve ao fato da habilidade fértil do espermatozoide ser multifatorial, ou seja, dependente de diversas características estruturais, morfofuncionais e moleculares. Ademais, os eventos que permitem os espermatozoides passarem por capacitação espermática, um pré-requisito para a fertilidade, têm intrigado os pesquisadores em vista da complexidade dos processos envolvidos e dos efeitos deletérios da criopreservação espermática. Esta revisão tem por objetivo compilar estudos que mostrem a relação entre a capacitação espermática e a fertilidade do sêmen bovino criopreservado, levando em consideração as técnicas de avaliação e os resultados até o momento.(AU)

The quality of cryopreserved semen, used in fixed-time artificial insemination (FTAI) in cattle, is one of the main factors that impact fertility and is related to the sperm production capacity of bulls, sperm cryotolerance, and the technical criteria for cryopreservation. In this sense, we must highlight the importance of quality control of semen batches before commercialization for the FTAI. In recent years, several techniques have progressed to more accurately evaluate semen batches and avoid using those that may result in impaired fertility. However, we still notice a high variability in the pregnancy rate between bulls and between semen batches. This divergence is due to the multifactorial sperm-fertilizing ability, i.e., it depends on several structural, morphofunctional, and molecular characteristics. In addition, the events that allow sperm to undergo sperm capacitation, a prerequisite for fertility, have intrigued researchers due to the complexity of the processes involved and the adverse effects of sperm cryopreservation. This review aims to compile studies that show the relationship between sperm capacitation and fertility in cryopreserved bovine semen, considering the evaluation techniques and results to date.(AU)

Seleção de touros para reprodução baseada no fenótipo e DEPs / Selection of bulls for reproduction based on EPD and phenotype

A fertilidade pode ser definida como a capacidade de gerar filhos normais, o que é essencial para o progresso genético, desde que os ascendentes tenham capacidade de transmitir características que venham impactar positivamente os índices zootécnicos e econômicos. Apesar do aumento expressivo do uso de biotécnicas reprodutivas, a maior parte das fêmeas bovinas aptas à reprodução no Brasil ainda são acasaladas por meio da monta natural. Torna-se importante então, não somente, a estimativa da saúde reprodutiva do touro, mas também a avaliação da sua qualidade genética que pode ser feita, por exemplo, pelo acesso os índices dos reprodutores nos diversos programas de melhoramento genético nacional ou pela utilização de escores de avaliação visual.(AU)

Fertility can be defined as the ability to generate normal descendants, which is essential for genetic progress, as long as the ancestors have the ability to transmit characteristics that will positively impact zootechnical and economic indices. Despite the significant increase in the use of reproduction biotechniques, most bovine females capable of reproduction in Brazil are still mated through natural mating. Therefore, it becomes important not only to estimate the reproductive health of the bull, but also to evaluate its genetic quality, which can be done, for example, by accessing the indices of the bulls in the various national genetic improvement programs or by using visual assessment scores.(AU)

Influence of thawing temperature on sperm motility, structure, and metabolism of frozen bovine semen / Influência da temperatura de descongelamento na motilidade, estrutura e metabolismo do sêmen bovino congelado

ABSTRACT: The heating rate used during semen thawing plays an important role in reducing structural and functional damage to spermatozoa. In this study, we evaluated the influence of thawing temperature on semen quality, reactive oxygen species (ROS) production, and mitochondrial activity of cryopreserved bovine semen. A total of 195 straws of 0.5 mL from five Holstein Friesian bulls were used (39 straws per bull). Samples underwent 8 to 22 years of storage; they were processed under a standard protocol with tris-egg yolk and stored in liquid nitrogen. Samples were thawed for 30 seconds in a water bath at T1: 36 °C, T2: 38 °C or T3: 40 °C. Sperm motility and kinematics, morphology, structural membrane integrity (SMI), functional membrane integrity (FMI), acrosome integrity (AI), ROS, and mitochondrial membrane potential (ΔΨM) of post-thawing bovine sperm were evaluated. Generalized linear models were fitted to the data. Each model included the effects of bull, storage time, and treatment. The Shapiro-Wilk test was used to assess data normality, and means were compared using the Tukey test. T2 and T3 showed better results for sperm motility and kinematic parameters, SMI (%) (T1 41.9 ± 2.3; T2 45.7 ± 1.9; T3 47.4 ± 2.8), ROS (RFU/min) (T1 0.026 ± 0.007; T2 0.032 ± 0.001; T3 0.031 ± 0.001) and high-ΔΨM (RFU x 103) (67.1± 0,4; 71.3 ± 0.4; 74.2 ± 0.4) (P < 0.05). However, T1 had higher FMI (39.3 ± 2.3) than T2 (34.0 ± 1.9) (P < 0.05), though not significantly (P > 0.05) different from T3 (38.4 ± 2.2). Thawing temperatures of 38 °C and 40 °C increases motility, kinetics, membrane integrity, mitochondrial activity and ROS of cryopreserved bovine semen, compared with more conventional thawing at 36 °C.

RESUMO: A taxa de aquecimento usada durante o descongelamento do sêmen desempenha um papel importante na redução dos danos estruturais e funcionais nos espermatozóides. O objetivo desta pesquisa foi avaliar a influência da temperatura de descongelamento na qualidade do sêmen, produção de espécies reativas de oxigênio (ROS) e atividade mitocondrial do sêmen bovino criopreservado. Foram utilizados 195 palhetas de 0,5 mL de cinco touros Holstein Friesian (39 palhetas por touro). As amostras passaram por oito a 22 anos de armazenamento e foram processadas sob protocolo padrão com Tris-gema de ovo e armazenadas em nitrogênio líquido. As temperaturas de descongelamento foram T1: 36 °C, T2: 38 °C, T3: 40 °C, cada uma por 30 segundos em banho-maria. Pós-descongelamento, a motilidade e cinética dos espermatozoides, morfologia, integridade estrutural da membrana (SMI), integridade funcional da membrana (FMI), integridade acrossomal (AI), ROS e potencial de membrana mitocondrial (ΔΨM) foram avaliados. Modelos lineares generalizados foram ajustados. Cada modelo incluiu os efeitos de touro, tempo de armazenamento e tratamento. A normalidade dos dados foi avaliada pelo teste de Shapiro-Wilk e as médias comparadas pelo teste de Tukey. T2 e T3 apresentaram resultados mais elevados para a maioria dos parâmetros de motilidade e cinemática espermática, SMI (%) (T1 41,9 ± 2,3; T2 45,7 ± 1,9; T3 47,4 ± 2,8), ROS (RFU/min) (T1 0,026 ± 0,007; T2 0,032 ± 0,001; T3 0,031 ± 0,001) e alto ΔΨM (RFU x 103) (67,1 ± 0,4; 71,3 ± 0,4; 74,2 ± 0,4) (P < 0,05). No entanto, T1 apresentou maior FMI (%) (39,3 ± 2,3) em comparação a T2 (34,0 ± 1,9) (P < 0,05), mas não foi diferente do T3 (38,4 ± 2,2) (P > 0,05). Conclui-se que as temperaturas de descongelamento de 38 °C e 40 °C produzem um aumento na motilidade, cinética, integridade de membrana, atividade mitocondrial e ROS do sêmen bovino criopreservado, em comparação com o uso mais convencional de uma temperatura de descongelamento de 36 °C.

Influence of thawing temperature on sperm motility, structure, and metabolism of frozen bovine semen / Influência da temperatura de descongelamento na motilidade, estrutura e metabolismo do sêmen bovino congelado

The heating rate used during semen thawing plays an important role in reducing structural and functional damage to spermatozoa. In this study, we evaluated the influence of thawing temperature on semen quality, reactive oxygen species (ROS) production, and mitochondrial activity of cryopreserved bovine semen. A total of 195 straws of 0.5 mL from five Holstein Friesian bulls were used (39 straws per bull). Samples underwent 8 to 22 years of storage; they were processed under a standard protocol with tris-egg yolk and stored in liquid nitrogen. Samples were thawed for 30 seconds in a water bath at T1: 36 °C, T2: 38 °C or T3: 40 °C. Sperm motility and kinematics, morphology, structural membrane integrity (SMI), functional membrane integrity (FMI), acrosome integrity (AI), ROS, and mitochondrial membrane potential (ΔΨM) of post-thawing bovine sperm were evaluated. Generalized linear models were fitted to the data. Each model included the effects of bull, storage time, and treatment. The Shapiro-Wilk test was used to assess data normality, and means were compared using the Tukey test. T2 and T3 showed better results for sperm motility and kinematic parameters, SMI (%) (T1 41.9 ± 2.3; T2 45.7 ± 1.9; T3 47.4 ± 2.8), ROS (RFU/min) (T1 0.026 ± 0.007; T2 0.032 ± 0.001; T3 0.031 ± 0.001) and high-ΔΨM (RFU x 103) (67.1± 0,4; 71.3 ± 0.4; 74.2 ± 0.4) (P < 0.05). However, T1 had higher FMI (39.3 ± 2.3) than T2 (34.0 ± 1.9) (P < 0.05), though not significantly (P > 0.05) different from T3 (38.4 ± 2.2). Thawing temperatures of 38 °C and 40 °C increases motility, kinetics, membrane integrity, mitochondrial activity and ROS of cryopreserved bovine semen, compared with more conventional thawing at 36 °C.

A taxa de aquecimento usada durante o descongelamento do sêmen desempenha um papel importante na redução dos danos estruturais e funcionais nos espermatozóides. O objetivo desta pesquisa foi avaliar a influência da temperatura de descongelamento na qualidade do sêmen, produção de espécies reativas de oxigênio (ROS) e atividade mitocondrial do sêmen bovino criopreservado. Foram utilizados 195 palhetas de 0,5 mL de cinco touros Holstein Friesian (39 palhetas por touro). As amostras passaram por oito a 22 anos de armazenamento e foram processadas sob protocolo padrão com Tris-gema de ovo e armazenadas em nitrogênio líquido. As temperaturas de descongelamento foram T1: 36 °C, T2: 38 °C, T3: 40 °C, cada uma por 30 segundos em banho-maria. Pós-descongelamento, a motilidade e cinética dos espermatozoides, morfologia, integridade estrutural da membrana (SMI), integridade funcional da membrana (FMI), integridade acrossomal (AI), ROS e potencial de membrana mitocondrial (ΔΨM) foram avaliados. Modelos lineares generalizados foram ajustados. Cada modelo incluiu os efeitos de touro, tempo de armazenamento e tratamento. A normalidade dos dados foi avaliada pelo teste de Shapiro-Wilk e as médias comparadas pelo teste de Tukey. T2 e T3 apresentaram resultados mais elevados para a maioria dos parâmetros de motilidade e cinemática espermática, SMI (%) (T1 41,9 ± 2,3; T2 45,7 ± 1,9; T3 47,4 ± 2,8), ROS (RFU/min) (T1 0,026 ± 0,007; T2 0,032 ± 0,001; T3 0,031 ± 0,001) e alto ΔΨM (RFU x 103) (67,1 ± 0,4; 71,3 ± 0,4; 74,2 ± 0,4) (P < 0,05). No entanto, T1 apresentou maior FMI (%) (39,3 ± 2,3) em comparação a T2 (34,0 ± 1,9) (P < 0,05), mas não foi diferente do T3 (38,4 ± 2,2) (P > 0,05). Conclui-se que as temperaturas de descongelamento de 38 °C e 40 °C produzem um aumento na motilidade, cinética, integridade de membrana, atividade mitocondrial e ROS do sêmen bovino criopreservado, em comparação com o uso mais convencional de uma temperatura de descongelamento de 36 °C.

Identification of Pentatrichomonas hominis in preputial washes of bulls in Brazil / Identificação de Pentatrichomonas hominis em lavado prepucial de touros no Brasil

The parabasalid Pentatrichomonas hominis is generally considered to represent a symbiotic component of the gastrointestinal microbiota in a wide variety of vertebrate hosts including humans. Nevertheless, a limited number of studies have raised the possibility that it may act as a pathogen of humans, dogs, and pigs and that some human infections may have a zoonotic origin. Data from North America revealed an association between P. hominis and the bovine urogenital tract, principally in bulls and rarely in cows. The importance of this observation is linked to possible interference in the accurate diagnosis of the economically important venereal pathogen Tritrichomonas foetus. The current study employed culture-based and molecular methods to examine the preputial cavities of four breeding bulls, raised in open pasture in southeastern Brazil, for the presence of trichomonads. Motile protozoa were isolated from three of the bulls and were definitively identified as P. hominis based on nucleotide sequencing of polymerase chain reaction (PCR) amplicons derived from the ribosomal RNA operon (ITS1-5.8S rDNA-ITS2) of the parasite. The potential implications of these findings for bovine and human health are discussed.(AU)

O parabasalídeo Pentatrichomonas hominis é geralmente considerado um componente simbiótico da microbiota gastrointestinal em uma ampla variedade de hospedeiros vertebrados, incluindo os humanos. No entanto, um número limitado de estudos levantou a possibilidade de que possa atuar como patógeno de humanos, cães e suínos, e que algumas infecções humanas possam ter origem zoonótica. Dados da América do Norte revelaram uma associação entre P. hominis e o trato urogenital bovino, principalmente, em touros e raramente em vacas. A importância dessa observação está ligada a uma possível interferência no diagnóstico preciso do patógeno venéreo de importância econômica Tritrichomonas foetus. O presente estudo empregou métodos baseados em cultura em combinação com técnicas moleculares, para examinar as cavidades prepuciais de quatro touros, criados em pastagem aberta no sudeste do Brasil, quanto à presença de tricomonas. Protozoários móveis foram isolados de três dos touros e foram definitivamente identificados como P. hominis com base no sequenciamento de nucleotídeos de amplicons geradas pela reação em cadeia da polimerase (PCR), empregando a região RNA ribossômico (ITS1-5.8S rDNA-ITS2) do parasita como alvo. Os potenciais implicações desses achados para a saúde bovina e humana são discutidas.(AU)

Tourinhos genômicos: o que são e sua importância para a produção animal / Genomic young bulls: what are them and their importance to livestock production

Neste texto são abordados dados sobre o rebanho pecuário brasileiro, sobre conceitos básicos de genômica, resultados da aplicação da genômica na área e novos projetos em andamento ligados à fertilidade de machos, com auxílio da genômica.(AU)

This text discusses data on the Brazilian results of the application of genomics in the area and new projects in progress related to male fertility, with the help of genomics.(AU)

Bull-bull mounts in Holstein bulls: a survey of its incidence, possible causes, and consequences in Uruguayan bull' breeders

Abstract Bulls frequently display male-male mounts, with consequences in the incidence of injuries, and possibly affecting the reproductive performance of the bulls. This behavior is known as the "buller syndrome" when appears in steers, with several individuals mounting one or a few penmates. The study aimed to collect information on the incidence of bull-bull mounts, the possible associated factors, the productive consequences, and management applied by distributing a survey to Holstein bull breeders in Uruguay. A survey was applied and responded by most Holstein breeders in Uruguay (30/33). Nineteen of the 30 breeders observed mounting behavior among bulls, and 15 of them considered it as a relevant problem. The breeders that observed the behavior had a greater number of bulls than those that did not observe it (P = 0.002). All of them observed that mounts were persistently directed towards the same individual (considering a specific period, while it remained in the group). Of these, 11 (58%) considered that this stopped only when the "buller" bull was removed from the group, mentioning that the behavior was frequently redirected to another individual. The mounts between bulls are a major problem in the breeding of Holstein bulls, with important consequences on weight gain and animal health, reproductive problems such as low libido and seminal quality, and even provoking the death of animals. Although not all breeders reported the existence of the problem, those with the bigger herds did. While some management and/or environmental conditions seem to influence (higher density, regrouping, managements that involve movement of animals, and spring) the incidence of bull-bull mounts, there are no standardized managements to avoid this behavior. Considering that most breeders were interested in including practices to minimize this problem if available, it would be essential to understand better the causes and predisposing factors to decrease its negative impacts.

Bull-bull mounts in Holstein bulls: a survey of its incidence, possible causes, and consequences in Uruguayan bull breeders

Bulls frequently display male-male mounts, with consequences in the incidence of injuries, and possibly affecting the reproductive performance of the bulls. This behavior is known as the “buller syndrome” when appears in steers, with several individuals mounting one or a few penmates. The study aimed to collect information on the incidence of bull-bull mounts, the possible associated factors, the productive consequences, and management applied by distributing a survey to Holstein bull breeders in Uruguay. A survey was applied and responded by most Holstein breeders in Uruguay (30/33). Nineteen of the 30 breeders observed mounting behavior among bulls, and 15 of them considered it as a relevant problem. The breeders that observed the behavior had a greater number of bulls than those that did not observe it (P = 0.002). All of them observed that mounts were persistently directed towards the same individual (considering a specific period, while it remained in the group). Of these, 11 (58%) considered that this stopped only when the “buller” bull was removed from the group, mentioning that the behavior was frequently redirected to another individual. The mounts between bulls are a major problem in the breeding of Holstein bulls, with important consequences on weight gain and animal health, reproductive problems such as low libido and seminal quality, and even provoking the death of animals. Although not all breeders reported the existence of the problem, those with the bigger herds did. While some management and/or environmental conditions seem to influence (higher density, regrouping, managements that involve movement of animals, and spring) the incidence of bull-bull mounts, there are no standardized managements to avoid this behavior. Considering that most breeders were interested in including practices to minimize this problem if available, it would be essential to understand better the causes and predisposing factors to decrease its negative impacts.(AU)

Hipoplasia testicular em bovinos: causas e consequências / Testicular hypoplasia in cattle: causes and consequences

A hipoplasia testicular ocorre na maioria dos animais domésticos, sendo caracterizada pela ausência ou diminuição do desenvolvimento do epitélio germinativo dos túbulos seminíferos. Apesar de nem todas as causas da hipoplasia testicular estarem completamente elucidadas, pode-se destacar as gênicas, as cromossômicas e as ambientais. A manifestação mais comum da hipoplasia gonadal clássica é de origem congênita e de caráter hereditário, determinada por um gene autossômico recessivo de penetrância incompleta. Apesar dos relatos de frequência serem escassos, essa patologia é descrita em quase todas as raças bovinas. Em rebanhos com alto grau de consanguinidade ou com uso intensivo de reprodutores homozigotos recessivos para a patologia, podem ocorrer manifestações em 5 a 15% dos animais. Nos casos de hipoplasia testicular, causada por genes recessivos de penetrância incompleta, tais genes podem passar para as gerações seguintes, causando subfertilidade tanto em machos como em fêmeas, sendo recomendada a eliminação de animais clinicamente suspeitos por assimetria testicular ou por baixo padrão de circunferência escrotal para a idade e peso. Touros com hipoplasia unilateral ou parcial são animais azoospérmicos ou oligospérmicos, porém quadros moderados a leves podem não estar associados a problemas de qualidade seminal, possibilitando que touros assintomáticos transmitam genes indesejáveis às próximas gerações. O estabelecimento de critérios rígidos de verificação de aspectos clínico-andrológicos é imprescindível para um diagnóstico precoce e para a seleção preliminar de reprodutores bovinos. As avaliações genômicas são caminhos promissores para mapear e identificar os principais marcadores associados à expressão gênica da hipoplasia testicular, com sua possível aplicação para seleção de touros de elite.

Testicular hypoplasia occurs in most domestic animals and is characterized by the absence or decreased development of the germinative epithelium of the seminiferous tubules. Although not all causes of testicular hypoplasia are elucidated, we can highlight the genetic, chromosomal and environmental causes. The manifestation of the most common classic gonadal hypoplasia is from congenital causes, determined by an autosomal recessive gene of incomplete penetrance. Although reports of frequency are scarce, this pathology is described in almost all bovine breeds. In herds with a high degree of inbreeding or intensive use of subfertile bulls, manifestations may occur in 5% to 15% of the animals. In cases of testicular hypoplasia, caused by recessive genes of incomplete penetrance, such genes can pass on to the following generations, causing subfertility in both males and females, being recommended the elimination of animals clinically suspected by testicular asymmetry or by low standard of scrotal circumference for age and weight. Bulls with unilateral or partial hypoplasia are azoospermic or oligospermic, however moderate conditions may not be associated with seminal quality problems, allowing asymptomatic bulls to spread undesirable genes to the next generations. The establishment of strict criteria for checking clinical and andrological aspects is essential for an early diagnosis and preliminary Bull's selection. Genomic evaluation is a promising way to map and identify the main genetic markers associated with testicular hypoplasia expression genes and its use for bull's selection.

Hipoplasia testicular em bovinos: causas e consequências / Testicular hypoplasia in cattle: causes and consequences

A hipoplasia testicular ocorre na maioria dos animais domésticos, sendo caracterizada pela ausência ou diminuição do desenvolvimento do epitélio germinativo dos túbulos seminíferos. Apesar de nem todas as causas da hipoplasia testicular estarem completamente elucidadas, pode-se destacar as gênicas, as cromossômicas e as ambientais. A manifestação mais comum da hipoplasia gonadal clássica é de origem congênita e de caráter hereditário, determinada por um gene autossômico recessivo de penetrância incompleta. Apesar dos relatos de frequência serem escassos, essa patologia é descrita em quase todas as raças bovinas. Em rebanhos com alto grau de consanguinidade ou com uso intensivo de reprodutores homozigotos recessivos para a patologia, podem ocorrer manifestações em 5 a 15% dos animais. Nos casos de hipoplasia testicular, causada por genes recessivos de penetrância incompleta, tais genes podem passar para as gerações seguintes, causando subfertilidade tanto em machos como em fêmeas, sendo recomendada a eliminação de animais clinicamente suspeitos por assimetria testicular ou por baixo padrão de circunferência escrotal para a idade e peso. Touros com hipoplasia unilateral ou parcial são animais azoospérmicos ou oligospérmicos, porém quadros moderados a leves podem não estar associados a problemas de qualidade seminal, possibilitando que touros assintomáticos transmitam genes indesejáveis às próximas gerações. O estabelecimento de critérios rígidos de verificação de aspectos clínico-andrológicos é imprescindível para um diagnóstico precoce e para a seleção preliminar de reprodutores bovinos. As avaliações genômicas são caminhos promissores para mapear e identificar os principais marcadores associados à expressão gênica da hipoplasia testicular, com sua possível aplicação para seleção de touros de elite.(AU)

Testicular hypoplasia occurs in most domestic animals and is characterized by the absence or decreased development of the germinative epithelium of the seminiferous tubules. Although not all causes of testicular hypoplasia are elucidated, we can highlight the genetic, chromosomal and environmental causes. The manifestation of the most common classic gonadal hypoplasia is from congenital causes, determined by an autosomal recessive gene of incomplete penetrance. Although reports of frequency are scarce, this pathology is described in almost all bovine breeds. In herds with a high degree of inbreeding or intensive use of subfertile bulls, manifestations may occur in 5% to 15% of the animals. In cases of testicular hypoplasia, caused by recessive genes of incomplete penetrance, such genes can pass on to the following generations, causing subfertility in both males and females, being recommended the elimination of animals clinically suspected by testicular asymmetry or by low standard of scrotal circumference for age and weight. Bulls with unilateral or partial hypoplasia are azoospermic or oligospermic, however moderate conditions may not be associated with seminal quality problems, allowing asymptomatic bulls to spread undesirable genes to the next generations. The establishment of strict criteria for checking clinical and andrological aspects is essential for an early diagnosis and preliminary Bull's selection. Genomic evaluation is a promising way to map and identify the main genetic markers associated with testicular hypoplasia expression genes and its use for bull's selection.(AU)

Inquérito sorológico de brucelose em machos e fêmeas bovinas em fazendas do Estado de Mato Grosso do Sul / Serological survey of brucellosis in males and females of cattle in the State of Mato Grosso do Sul

Objetivou-se avaliar a ocorrência de animais soro reagentes à brucelose bovina em fazendas localizadas no Estado de Mato Grosso do Sul, por meio de exame sorológico utilizando o Antígeno Acidificado Tamponado (AAT) e discutir as possíveis diferenças entre as soroprevalências de fêmeas e machos. Foram avaliados, a partir do teste de triagem com Antígeno Acidificado Tamponado (AAT), 724 bovinos da raça Nelore, sendo 274 machos e 450 fêmeas, provenientes de oito propriedades com histórico de problemas reprodutivos. O teste foi procedido conforme o protocolo determinado pelo Ministério da Agricultura, Pecuária e Abastecimento (MAPA). Os resultados demonstraram baixa soroprevalência da doença nos bovinos testados, sendo detectada prevalência para a doença de 1,10% nos machos e 2,88% nas fêmeas.Quando se considera o touro isoladamente nos rebanhos, pode-se perceber que a fertilidade é muito mais importante nos machos do que nas fêmeas individualmente, uma vez que os touros podem se acasalar com um número muito maior de fêmeas, seja na monta natural ou na inseminação artificial, demonstrando a importância do inquérito epidemiológico na população geral, principalmente nos machos. A maior frequência da doença foi encontrada nas fêmeas podendo estar relacionada à infecção por Brucella spp. no ambiente decorrente de parto ou aborto tornando as fêmeas transmissoras permanentes da doença.

The objective of this study was to evaluate the occurrence of seroreactive animals to bovine brucellosis in farms located in the State of Mato Grosso do Sul, by means of a serological examination using the Acidified Buffered Antigen (AAT) and to discuss the possible differences between the seroprevalence of females and males. A total of 724 Nellore cattle, 274 males and 450 females, from eight farms with a history of reproductive problems, were evaluated using the screening test with Acidified Buffered Antigen (AAT). The test was carried out according to the protocol determined by the Ministry of Agriculture, Livestock and Food Supply (MAPA).The results showed a low seroprevalence of the disease in the tested cattle, with a prevalence of 1.10% in males and 2.88% in females.When considered the bull alone in herds, it can be shown that fertility is much more important in males than in females individually, since bulls can mate with a much larger number of females, either in natural mating or in artificial insemination, demonstrating the importance of epidemiological survey in the general population, especially in males. The highest frequency of the disease was found in females and may be related to infection by Brucella spp. in the environment from childbirth or abortion making females permanent transmitters of the disease.

Inquérito sorológico de brucelose em machos e fêmeas bovinas em fazendas do Estado de Mato Grosso do Sul / Serological survey of brucellosis in males and females of cattle in the State of Mato Grosso do Sul

Objetivou-se avaliar a ocorrência de animais soro reagentes à brucelose bovina em fazendas localizadas no Estado de Mato Grosso do Sul, por meio de exame sorológico utilizando o Antígeno Acidificado Tamponado (AAT) e discutir as possíveis diferenças entre as soroprevalências de fêmeas e machos. Foram avaliados, a partir do teste de triagem com Antígeno Acidificado Tamponado (AAT), 724 bovinos da raça Nelore, sendo 274 machos e 450 fêmeas, provenientes de oito propriedades com histórico de problemas reprodutivos. O teste foi procedido conforme o protocolo determinado pelo Ministério da Agricultura, Pecuária e Abastecimento (MAPA). Os resultados demonstraram baixa soroprevalência da doença nos bovinos testados, sendo detectada prevalência para a doença de 1,10% nos machos e 2,88% nas fêmeas.Quando se considera o touro isoladamente nos rebanhos, pode-se perceber que a fertilidade é muito mais importante nos machos do que nas fêmeas individualmente, uma vez que os touros podem se acasalar com um número muito maior de fêmeas, seja na monta natural ou na inseminação artificial, demonstrando a importância do inquérito epidemiológico na população geral, principalmente nos machos. A maior frequência da doença foi encontrada nas fêmeas podendo estar relacionada à infecção por Brucella spp. no ambiente decorrente de parto ou aborto tornando as fêmeas transmissoras permanentes da doença.(AU)

The objective of this study was to evaluate the occurrence of seroreactive animals to bovine brucellosis in farms located in the State of Mato Grosso do Sul, by means of a serological examination using the Acidified Buffered Antigen (AAT) and to discuss the possible differences between the seroprevalence of females and males. A total of 724 Nellore cattle, 274 males and 450 females, from eight farms with a history of reproductive problems, were evaluated using the screening test with Acidified Buffered Antigen (AAT). The test was carried out according to the protocol determined by the Ministry of Agriculture, Livestock and Food Supply (MAPA).The results showed a low seroprevalence of the disease in the tested cattle, with a prevalence of 1.10% in males and 2.88% in females.When considered the bull alone in herds, it can be shown that fertility is much more important in males than in females individually, since bulls can mate with a much larger number of females, either in natural mating or in artificial insemination, demonstrating the importance of epidemiological survey in the general population, especially in males. The highest frequency of the disease was found in females and may be related to infection by Brucella spp. in the environment from childbirth or abortion making females permanent transmitters of the disease.(AU)

Inquérito sorológico de brucelose em machos e fêmeas bovinas em fazendas do Estado de Mato Grosso do Sul / Serological survey of brucellosis in males and females of cattle in the State of Mato Grosso do Sul

Objetivou-se avaliar a ocorrência de animais soro reagentes à brucelose bovina em fazendas localizadas no Estado de Mato Grosso do Sul, por meio de exame sorológico utilizando o Antígeno Acidificado Tamponado (AAT) e discutir as possíveis diferenças entre as soroprevalências de fêmeas e machos. Foram avaliados, a partir do teste de triagem com Antígeno Acidificado Tamponado (AAT), 724 bovinos da raça Nelore, sendo 274 machos e 450 fêmeas, provenientes de oito propriedades com histórico de problemas reprodutivos. O teste foi procedido conforme o protocolo determinado pelo Ministério da Agricultura, Pecuária e Abastecimento (MAPA). Os resultados demonstraram baixa soroprevalência da doença nos bovinos testados, sendo detectada prevalência para a doença de 1,10% nos machos e 2,88% nas fêmeas.Quando se considera o touro isoladamente nos rebanhos, pode-se perceber que a fertilidade é muito mais importante nos machos do que nas fêmeas individualmente, uma vez que os touros podem se acasalar com um número muito maior de fêmeas, seja na monta natural ou na inseminação artificial, demonstrando a importância do inquérito epidemiológico na população geral, principalmente nos machos. A maior frequência da doença foi encontrada nas fêmeas podendo estar relacionada à infecção por Brucella spp. no ambiente decorrente de parto ou aborto tornando as fêmeas transmissoras permanentes da doença.

The objective of this study was to evaluate the occurrence of seroreactive animals to bovine brucellosis in farms located in the State of Mato Grosso do Sul, by means of a serological examination using the Acidified Buffered Antigen (AAT) and to discuss the possible differences between the seroprevalence of females and males. A total of 724 Nellore cattle, 274 males and 450 females, from eight farms with a history of reproductive problems, were evaluated using the screening test with Acidified Buffered Antigen (AAT). The test was carried out according to the protocol determined by the Ministry of Agriculture, Livestock and Food Supply (MAPA).The results showed a low seroprevalence of the disease in the tested cattle, with a prevalence of 1.10% in males and 2.88% in females.When considered the bull alone in herds, it can be shown that fertility is much more important in males than in females individually, since bulls can mate with a much larger number of females, either in natural mating or in artificial insemination, demonstrating the importance of epidemiological survey in the general population, especially in males. The highest frequency of the disease was found in females and may be related to infection by Brucella spp. in the environment from childbirth or abortion making females permanent transmitters of the disease.

Influência da cinética espermática sobre a taxa de prenhez na inseminação artificial em tempo fixo em bovinos / Influence of sperm kinetics on pregnancy rate in fixed-time artificial inseminations in cattle

The aim of the study was to evaluate the influence of hyperactivated sperm kinetics on pregnancy rate in IATF. Two experimental groups were established, based on the results of the semen analysis in the CASA system: groups of bulls with hyperactivated sperm (N = 10; HIPER) and bulls with non-hyperactivated sperm (N = 14; N HIPER). Differences between groups were estimated by the t test, and a significance level <5% was considered. Highervalues for the variables were identified in the HIPER group: VAP; VSL; VCL; ALH; RAPID cells and SLOW cells. On the other hand: BCF; STR; LIN; WOB and MEDIUM cells, which had higher values in the N HIPER group. No difference was found for the pregnancy rate variable between groups (p=0.454). Therefore, although the CASA system is an objective method of analysis, we can consider that it alone is not sufficient to predict seminal fertility, but when associated with other techniques such as: specific software and multivariate statistics that identify subpopulations, if makes it an important methodology for assessing semen quality.

Influência da cinética espermática sobre a taxa de prenhez na inseminação artificial em tempo fixo em bovinos / Influence of sperm kinetics on pregnancy rate in fixed-time artificial inseminations in cattle

The aim of the study was to evaluate the influence of hyperactivated sperm kinetics on pregnancy rate in IATF. Two experimental groups were established, based on the results of the semen analysis in the CASA system: groups of bulls with hyperactivated sperm (N = 10; HIPER) and bulls with non-hyperactivated sperm (N = 14; N HIPER). Differences between groups were estimated by the t test, and a significance level <5% was considered. Highervalues for the variables were identified in the HIPER group: VAP; VSL; VCL; ALH; RAPID cells and SLOW cells. On the other hand: BCF; STR; LIN; WOB and MEDIUM cells, which had higher values in the N HIPER group. No difference was found for the pregnancy rate variable between groups (p=0.454). Therefore, although the CASA system is an objective method of analysis, we can consider that it alone is not sufficient to predict seminal fertility, but when associated with other techniques such as: specific software and multivariate statistics that identify subpopulations, if makes it an important methodology for assessing semen quality.(AU)

Scrotal thermography to assess the seminal quality in Nelore and Girolando bulls / Termografia escrotal e a relação com a qualidade seminal em touros Nelore e Girolando

Bull selection by andrological examination aims to estimate the reproductive capacity of the male. Bulls of zebu origin adapt better to high temperatures than bulls of taurine origin, which may influence scrotum temperature and seminal quality due to the imbalance of testicular thermoregulation. The objective of this study was to investigate the relationship between bioclimatic variables, the temperature of body and scrotal areas, assessed with infrared thermography, and the quality of fresh and post-thawed semen in zebu Nelore bulls (Bos taurus indicus) and Girolando bulls (Bos taurus taurus x Bos taurus indicus). Bulls were kept in pickets with access to water, mineral mix and a diet supplemented with concentrate. Infrared thermographs of the scrotum, orbital globe and muzzle were performed twice a week with a Flir E40 thermal imager. For scrotal thermograms, we analyzed the temperatures of the spermatic cord, proximal and distal portion of the testes and tail of the epididymis using the Flir Tools software. Samples were collected using an artificial vagina and the ejaculates were processed and frozen in liquid nitrogen until further analyses. Data were analyzed with the Tukey test or the Kruskall-Wallis test, depending on their normal distribution. Our results showed differences (p < 0.05) between the two breeds regarding the temperature in the ocular globe, spermatic cord and proximal portion of the scrotum. Nelore bulls presented lower temperature in the body and in certain regions of the scrotum compared to Girolando bulls. Seminal characteristics varied between breeds, with the Nelore breed presenting better semen. Positive correlations were observed between minor sperm defects and ventral regions of the testes and tails of the epididymis in Girolando bulls. Nelore bulls were less influenced by climatic variables and presented lower temperature in skin surface areas in the...

A seleção de touros pelo exame andrológico visa estimar a capacidade reprodutiva do macho. Touros de origem zebuína apresentam melhor adaptabilidade às altas temperaturas, em relação aos touros de origem taurina, podendo influenciar na temperatura do escroto e na qualidade seminal pelo desequilíbrio da termorregulação testicular. Objetivou-se avaliar a influência das variáveis bioclimáticas e a relação de perfis de termogramas por infravermelho de áreas do corpo e escroto com a qualidade do sêmen fresco e descongelado em touros das raças Nelore e Girolando, mantidos em Central de Inseminação Artificial. Foram utilizados quatro touros Nelore e quatro Girolando, mantidos em piquetes com acesso a água e mistura mineral; e suplementação com concentrado. Termografias infravermelhas do escroto, globo ocular e mufla foram realizadas duas vezes por semana com termovisor Flir E40. Para os termogramas escrotais, as temperaturas do cordão espermático, porção proximal e distal dos testículos e cauda do epidídimo foram analisadas utilizando o software Flir Tools. Foram realizadas colheitas de sêmen com vagina artificial e os ejaculados processados e congelados em nitrogênio líquido e analisados na pós-descongelação. Os dados passaram pelo teste de normalidade e teste Tukey; e na ausência de normalidade pelo teste Kruskall- Wallis. Entre raças, foram observadas diferenças (P < 0,05) nas temperaturas do globo ocular, cordão espermático e porção proximal do escroto. Os touros Nelore apresentaram menor temperatura corpórea e de regiões do escroto, em relação aos touros Girolando. As características seminais variaram entre raças (P < 0,05), a raça Nelore apresentou sêmen de melhor qualidade. Correlações positivas (P < 0,05) foram observadas entre defeitos espermáticos menores e temperaturas da região ventral dos testículos e das caudas dos epidídimos. em touros Girolando. Os touros da raça...

Scrotal thermography to assess the seminal quality in Nelore and Girolando bulls / Termografia escrotal e a relação com a qualidade seminal em touros Nelore e Girolando

Bull selection by andrological examination aims to estimate the reproductive capacity of the male. Bulls of zebu origin adapt better to high temperatures than bulls of taurine origin, which may influence scrotum temperature and seminal quality due to the imbalance of testicular thermoregulation. The objective of this study was to investigate the relationship between bioclimatic variables, the temperature of body and scrotal areas, assessed with infrared thermography, and the quality of fresh and post-thawed semen in zebu Nelore bulls (Bos taurus indicus) and Girolando bulls (Bos taurus taurus x Bos taurus indicus). Bulls were kept in pickets with access to water, mineral mix and a diet supplemented with concentrate. Infrared thermographs of the scrotum, orbital globe and muzzle were performed twice a week with a Flir E40 thermal imager. For scrotal thermograms, we analyzed the temperatures of the spermatic cord, proximal and distal portion of the testes and tail of the epididymis using the Flir Tools software. Samples were collected using an artificial vagina and the ejaculates were processed and frozen in liquid nitrogen until further analyses. Data were analyzed with the Tukey test or the Kruskall-Wallis test, depending on their normal distribution. Our results showed differences (p < 0.05) between the two breeds regarding the temperature in the ocular globe, spermatic cord and proximal portion of the scrotum. Nelore bulls presented lower temperature in the body and in certain regions of the scrotum compared to Girolando bulls. Seminal characteristics varied between breeds, with the Nelore breed presenting better semen. Positive correlations were observed between minor sperm defects and ventral regions of the testes and tails of the epididymis in Girolando bulls. Nelore bulls were less influenced by climatic variables and presented lower temperature in skin surface areas in the...(AU)

A seleção de touros pelo exame andrológico visa estimar a capacidade reprodutiva do macho. Touros de origem zebuína apresentam melhor adaptabilidade às altas temperaturas, em relação aos touros de origem taurina, podendo influenciar na temperatura do escroto e na qualidade seminal pelo desequilíbrio da termorregulação testicular. Objetivou-se avaliar a influência das variáveis bioclimáticas e a relação de perfis de termogramas por infravermelho de áreas do corpo e escroto com a qualidade do sêmen fresco e descongelado em touros das raças Nelore e Girolando, mantidos em Central de Inseminação Artificial. Foram utilizados quatro touros Nelore e quatro Girolando, mantidos em piquetes com acesso a água e mistura mineral; e suplementação com concentrado. Termografias infravermelhas do escroto, globo ocular e mufla foram realizadas duas vezes por semana com termovisor Flir E40. Para os termogramas escrotais, as temperaturas do cordão espermático, porção proximal e distal dos testículos e cauda do epidídimo foram analisadas utilizando o software Flir Tools. Foram realizadas colheitas de sêmen com vagina artificial e os ejaculados processados e congelados em nitrogênio líquido e analisados na pós-descongelação. Os dados passaram pelo teste de normalidade e teste Tukey; e na ausência de normalidade pelo teste Kruskall- Wallis. Entre raças, foram observadas diferenças (P < 0,05) nas temperaturas do globo ocular, cordão espermático e porção proximal do escroto. Os touros Nelore apresentaram menor temperatura corpórea e de regiões do escroto, em relação aos touros Girolando. As características seminais variaram entre raças (P < 0,05), a raça Nelore apresentou sêmen de melhor qualidade. Correlações positivas (P < 0,05) foram observadas entre defeitos espermáticos menores e temperaturas da região ventral dos testículos e das caudas dos epidídimos. em touros Girolando. Os touros da raça...(AU)

Effects of treatment with quercetin on the quality of cryopreserved bovine semen

Background: Semen cryopreservation is one of the most common biotechnologies in the reproduction of animals ofagricultural interest, especially bulls. However, cryopreservation can be harmful to sperm cells, with susceptibility tooxidative stress being one of the causes. The addition of antioxidants such as quercetin may inhibit and/or reduce suchdamage, reducing fertility. Quercetin can increasing sperm motility and interaction capacity between spermatozoa-oocyte,to increase cellular metabolism and reduced DNA fragmentation and oxidation following thawing. Therefore, the objective of this study was to evaluate the protective effect of quercetin on the metabolism of bovine semen following thawing.Materials, Methods & Results: Three Brahman bulls in reproduction age and previously considered fit for reproductionwere used. The semen samples were collected via the electroejaculation method, and the samples were homogenized toform pooled semen from three ejaculates, which was diluted in Tris-yolk egg-glicerol diluent medium. Quercetin was addedto diluent, to final concentrations of 0, 5, 10, 15 and 20 μg.mL-1 in each group. The samples were kept frozen in strawsof 500 μL, with concentration of 40,000,000 spermatozoid / mL for 15 days and were thawed in water at 36°C for 30 s.All the tests was performed in five replicates. The cell metabolism status was evaluated by quantification of superoxideradical production with a nitroblue tetrazolium test (NBT) and scanning spectrophotometry. By spermatic evaluation, thefollowing parameters were evaluated via the computerized system of sperm analysis (CASA): total motility (TM, %),progressive motility (PM, %), velocity curved line (VCL, mm/s), velocity straight line (VSL, mm/s), velocity averagepath (VAP, mm/s), distance curved line (DCL, mm), distance straight line (DSL, mm), distance average path (DAP, mm),amplitude of lateral head displacement (ALH, mm), beat cross frequency (BCF, Hz), wobble...

Evaluation of scrotal temperature in different testicular shapes by infrared thermography in Braford bulls

Background: The mechanisms of testicular thermoregulation may influence the blood flow provided by the testicularartery, where the proper blood supply to the testicle is crucial for promotingspermatogenesis and reproductive functionin bulls. The size and shape of the testicles are determined by genetic mechanisms and environmental effects. A betterunderstanding of the relationships between the anatomical characteristics of the testicles and scrotum can support a betterreproductive assessment. The purpose of the current study was to evaluate the testicular temperature of different scrotalshapes using infrared thermography in bulls.Materials, Methods & Results: We evaluated 132 Braford bulls with an average age of 24 months. The evaluation of breeding bull semen was performed prior to the beginning of the experiment. Then, animals were selected on the basis of the sizeof their testes, which was determined by dividing the average width by the average length. The scrotal circumference wasmeasured with a millimeter tape positioned around the largest circumference. Testicular and ocular temperature measurementsand analysis were conducted using an infrared thermal camera, Flir T440 with emissivity of 0.98 and thermal sensitivity of0.05°C. Testicular scrotum temperature and testicular shape were analyzed with one-way ANOVA using Minitab 16, andvalues of P < 0.05 were considered statistically significant. We observed that 67.42% of testicle shapes were long-oval,and 32.58% were long-moderate. The testicular temperature was higher in bulls with the long-moderate shape comparedto those with the long-oval shape (P < 0.05). The mean length was higher in long-moderate shaped testicles compared tothose of the long-oval shape (P < 0.01). There was no significant differences...

Effects of treatment with quercetin on the quality of cryopreserved bovine semen

Background: Semen cryopreservation is one of the most common biotechnologies in the reproduction of animals ofagricultural interest, especially bulls. However, cryopreservation can be harmful to sperm cells, with susceptibility tooxidative stress being one of the causes. The addition of antioxidants such as quercetin may inhibit and/or reduce suchdamage, reducing fertility. Quercetin can increasing sperm motility and interaction capacity between spermatozoa-oocyte,to increase cellular metabolism and reduced DNA fragmentation and oxidation following thawing. Therefore, the objective of this study was to evaluate the protective effect of quercetin on the metabolism of bovine semen following thawing.Materials, Methods & Results: Three Brahman bulls in reproduction age and previously considered fit for reproductionwere used. The semen samples were collected via the electroejaculation method, and the samples were homogenized toform pooled semen from three ejaculates, which was diluted in Tris-yolk egg-glicerol diluent medium. Quercetin was addedto diluent, to final concentrations of 0, 5, 10, 15 and 20 μg.mL-1 in each group. The samples were kept frozen in strawsof 500 μL, with concentration of 40,000,000 spermatozoid / mL for 15 days and were thawed in water at 36°C for 30 s.All the tests was performed in five replicates. The cell metabolism status was evaluated by quantification of superoxideradical production with a nitroblue tetrazolium test (NBT) and scanning spectrophotometry. By spermatic evaluation, thefollowing parameters were evaluated via the computerized system of sperm analysis (CASA): total motility (TM, %),progressive motility (PM, %), velocity curved line (VCL, mm/s), velocity straight line (VSL, mm/s), velocity averagepath (VAP, mm/s), distance curved line (DCL, mm), distance straight line (DSL, mm), distance average path (DAP, mm),amplitude of lateral head displacement (ALH, mm), beat cross frequency (BCF, Hz), wobble...(AU)