Identification of Pentatrichomonas hominis in preputial washes of bulls in Brazil.

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.

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)

Motor, cognitive and mobility deficits in 1000 geriatric patients: protocol of a quantitative observational study before and after routine clinical geriatric treatment - the ComOn-study.

BACKGROUND: Motor and cognitive deficits and consequently mobility problems are common in geriatric patients. The currently available methods for diagnosis and for the evaluation of treatment in this vulnerable cohort are limited. The aims of the ComOn (COgnitive and Motor interactions in the Older populatioN) study are (i) to define quantitative markers with clinical relevance for motor and cognitive deficits, (ii) to investigate the interaction between both motor and cognitive deficits and (iii) to assess health status as well as treatment outcome of 1000 geriatric inpatients in hospitals of Kiel (Germany), Brescia (Italy), Porto (Portugal), Curitiba (Brazil) and Bochum (Germany). METHODS: This is a prospective, explorative observational multi-center study. In addition to the comprehensive geriatric assessment, quantitative measures of reduced mobility and motor and cognitive deficits are performed before and after a two week's inpatient stay. Components of the assessment are mobile technology-based assessments of gait, balance and transfer performance, neuropsychological tests, frailty, sarcopenia, autonomic dysfunction and sensation, and questionnaires to assess behavioral deficits, activities of daily living, quality of life, fear of falling and dysphagia. Structural MRI and an unsupervised 24/7 home assessment of mobility are performed in a subgroup of participants. The study will also investigate the minimal clinically relevant change of the investigated parameters. DISCUSSION: This study will help form a better understanding of symptoms and their complex interactions and treatment effects in a large geriatric cohort.

Principal component and cluster analyses of production and fertility traits in Red Sindhi dairy cattle breed in Brazil.

The objective of this study was to investigate the relationship among functional traits (age at first calving (AFC), calving interval (CI), reproductive efficiency (RE), total milk yield (TMY), and lactation period (LP)) in Red Sindhi breed through multivariate techniques. For this goal, performance data provided by the Brazilian Association of Zebu Breeders related to 560 Red Sindhi dairy cattle from 28 different herds in Brazil, born in the period from 1987 to 2011, were used. Principal component analysis with correlation matrix was used to find the relationship among AFC, CI, RE, TMY, and LP. It was found that for all functional traits, first 3 principal components explained more than 90% of the total variation. Clustering analysis was performed based on Tocher method, and results showed physiological relationships among functional traits. By cluster analysis, twelve different groups were generated from the pool of Sindhi herds analyzed, with a great homogeneity among females for the traits evaluated and only few females generating separate groups. Four hundred and twenty-nine females were clustered in one group, representing 76.60% of the genotypes. Total milk yield (TMY) showed 71.92% of the total variation, and age at first calving (AFC) contributed with 23.06% of the variation, being the two most important traits for the variability of the data set. In conclusion, the multivariate procedures were effective in generating the correlations among the functional traits, showing that CI is correlated with RE and all these functional traits are related with total milk yield.

Influence of age and weight of Girolando heifers on uterine and ovarian development

The present study aimed to correlate the age and weight of Girolando heifers with uterine and ovarian development. Sixty heifers between 12 and 36 months old were weighed and subjected to ultrasound assessment to measure the diameters of each uterine horn and ovaries, monthly. These measures continued until their first ovulation. The animals were divided, for data analysis, according to their age into five groups: GI (12 to 14 months), GII (15 to 18 months), GIII (19 to 24 months), GIV (25 to 30 months), and GV (31 to 36 months). The dispersion diagram was used to assess the correlation between data collected monthly from uterus/ovaries and weight/age. An average daily growth of 0.0032 mm was recorded for the right ovary (RO) and 0.0051 mm for the left ovary (LO). The average size of the RO in GI was 17.58 mm and the LO was 15.28 mm; in GII, the RO was 16.72 mm and the LO was 15.89 mm; in GIII, the RO was 18.37 mm and the LO was 16.55 mm; in GIV, the RO was 19.09 mm and the LO was 17.49 mm; and in GV, the RO was 19.89 mm and the LO was 18.96 mm. The uterine horns showed an average daily growth of 0.0064 mm and 0.0071 mm for the right (RU) and left (LU) uterine horn, respectively. The average sizes of the uterine horns per group were: RU, 11.46 mm and LU, 11.48 mm; RU, 12.41 mm and LU, 12.63 mm; RU, 13.16 mm and LU, 13.19 mm; RU 14.30 mm and LU, 14.58 mm; and RU, 16.12 mm and LU, 16.68 mm for the groups GI, GII, GIII, GIV, and GV, respectively. The heifers showed an average daily weight gain of 0.224 kg and the groups GI, GII, GIII, GIV, and GV had an average weight of 220.5, 239.3, 287.6, 332.9, and 380.1 kg, respectively. Therefore, weight growth correlates with the growth of the ovaries and uterine horns; furthermore, these data correlate positively as the animals age.(AU)

Weaning weight and optimization of reproductive efficiency in Nellore females subjected to timed artificial insemination

The objective of this study was to evaluate the effect of timed artificial insemination (TAI) on pregnancy rates, reproductive efficiency, and mean weaning weight of calves at the end of breeding season in Nellore females. In this work, 744 Nellore females were divided into two groups: in group I (n = 396), the females were subjected to natural service during the breeding season, which lasts for 180 days. In group II (n = 348), a hormonal protocol was performed for synchronization of ovulation, and the females were subjected to TAI. Afterwards, these latter females were then serviced by a cleanup bull until the end of the breeding season. The group II obtained a higher pregnancy rate as well as higher reproductive efficiency compared with group I. The weaning weight of group II calves was greater than that of group I. The use of TAI combined with cleanup bulls enables higher pregnancy rates and a better reproductive efficiency in relation to the use of only natural service. In addition, weaning calves born from TAI are heavier than calves born from natural service.(AU)

Comparison of estradiol benzoate and cypionate in Girolando cows submitted to a timed artificial insemination / Comparação do benzoato e do cipionato de estradiol em vacas Girolando submetidas à Inseminação Artificial em Tempo Fixo

The various studies on the manipulation of the estrous cycle culminated in the development of estrous and ovulation synchronization protocols, to the point of defining an optimum moment for artificial insemination. The induction of ovulation is a primordial part for the determination of the moment of the TAI, so to study which hormones and how they behave allows a better understanding of this physiological process and, to manipulate it efficiently. The aim of the present study was to compare the use of estradiol benzoate (EB) and cypionate (ECP) as ovulation inducer in Girolando cows submitted to Timed Artificial Insemination (TAI). Ovulations of 108 Girolando cows were synchronized and the initial day of treatment, recorded as D0, which was when the animals received an intravaginal device containing 1g of progestogen and an intramuscular application (im) of 2mg of EB. After 8 days (D8), the device was removed and 500g of cloprostenol (im) was administered to all females. Then, the animals were randomly divided into two treatments: BG Group (n = 52) and CG Group (n = 56). The CG animals received 1mg of ECP (im) as the ovulation inducer at the time of device removal, while BG Group cows received 1mg of EB (im) 24 h later (D9). TAI occurred at D10. After device removal, ultrasound

Os diversos estudos sobre manipulação do ciclo estral culminaram com o desenvolvimento de protocolos de sincronização do estro e da ovulação, a ponto de se definir um momento ótimo para a inseminação artificial. A indução da ovulação é parte primordial para a determinação do momento da IATF. Dessa forma, estudar quais hormônios e como eles se comportam permite compreender melhor esse processo fisiológico e, ainda, manipulá-lo de forma eficiente. O objetivo do presente estudo foi comparar o uso de benzoato de estradiol (BE) e cipionato (ECP) em vacas Girolando submetidas à inseminação artificial em tempo fixo (IATF). As ovulações de 108 vacas Girolando foram sincronizadas e no início do tratamento, D0, os animais receberam um dispositivo intravaginal contendo 1g de progestágeno e uma aplicação intramuscular (im) de 2mg de BE. No D8, o dispositivo foi removido e 500g de cloprostenol (im) foram administrados a todas as fêmeas. Depois disso, os animais foram divididos aleatoriamente em dois tratamentos: Grupo GB (n = 52) e Grupo GC (n = 56). Os animais do Grupo GC receberam 1mg de ECP (im) como indutor de ovulação no momento da retirada do dispositivo, enquanto as vacas do Grupo GB receberam 1mg de BE (im) 24 horas depois (D9). IATF ocorreu em D10. Após a remoção do dispositivo, as avaliações ultrassonográficas foram realizadas a cada 12 horas até a ovulação. Os parâmetros reprodu

Comparison of estradiol benzoate and cypionate in Girolando cows submitted to a timed artificial insemination / Comparação do benzoato e do cipionato de estradiol em vacas Girolando submetidas à Inseminação Artificial em Tempo Fixo

The various studies on the manipulation of the estrous cycle culminated in the development of estrous and ovulation synchronization protocols, to the point of defining an optimum moment for artificial insemination. The induction of ovulation is a primordial part for the determination of the moment of the TAI, so to study which hormones and how they behave allows a better understanding of this physiological process and, to manipulate it efficiently. The aim of the present study was to compare the use of estradiol benzoate (EB) and cypionate (ECP) as ovulation inducer in Girolando cows submitted to Timed Artificial Insemination (TAI). Ovulations of 108 Girolando cows were synchronized and the initial day of treatment, recorded as D0, which was when the animals received an intravaginal device containing 1g of progestogen and an intramuscular application (im) of 2mg of EB. After 8 days (D8), the device was removed and 500g of cloprostenol (im) was administered to all females. Then, the animals were randomly divided into two treatments: BG Group (n = 52) and CG Group (n = 56). The CG animals received 1mg of ECP (im) as the ovulation inducer at the time of device removal, while BG Group cows received 1mg of EB (im) 24 h later (D9). TAI occurred at D10. After device removal, ultrasound

Os diversos estudos sobre manipulação do ciclo estral culminaram com o desenvolvimento de protocolos de sincronização do estro e da ovulação, a ponto de se definir um momento ótimo para a inseminação artificial. A indução da ovulação é parte primordial para a determinação do momento da IATF. Dessa forma, estudar quais hormônios e como eles se comportam permite compreender melhor esse processo fisiológico e, ainda, manipulá-lo de forma eficiente. O objetivo do presente estudo foi comparar o uso de benzoato de estradiol (BE) e cipionato (ECP) em vacas Girolando submetidas à inseminação artificial em tempo fixo (IATF). As ovulações de 108 vacas Girolando foram sincronizadas e no início do tratamento, D0, os animais receberam um dispositivo intravaginal contendo 1g de progestágeno e uma aplicação intramuscular (im) de 2mg de BE. No D8, o dispositivo foi removido e 500g de cloprostenol (im) foram administrados a todas as fêmeas. Depois disso, os animais foram divididos aleatoriamente em dois tratamentos: Grupo GB (n = 52) e Grupo GC (n = 56). Os animais do Grupo GC receberam 1mg de ECP (im) como indutor de ovulação no momento da retirada do dispositivo, enquanto as vacas do Grupo GB receberam 1mg de BE (im) 24 horas depois (D9). IATF ocorreu em D10. Após a remoção do dispositivo, as avaliações ultrassonográficas foram realizadas a cada 12 horas até a ovulação. Os parâmetros reprodu

Comparison of estradiol benzoate and cypionate in Girolando cows submitted to a timed artificial insemination / Comparação do benzoato e do cipionato de estradiol em vacas Girolando submetidas à Inseminação Artificial em Tempo Fixo

The various studies on the manipulation of the estrous cycle culminated in the development of estrous and ovulation synchronization protocols, to the point of defining an optimum moment for artificial insemination. The induction of ovulation is a primordial part for the determination of the moment of the TAI, so to study which hormones and how they behave allows a better understanding of this physiological process and, to manipulate it efficiently. The aim of the present study was to compare the use of estradiol benzoate (EB) and cypionate (ECP) as ovulation inducer in Girolando cows submitted to Timed Artificial Insemination (TAI). Ovulations of 108 Girolando cows were synchronized and the initial day of treatment, recorded as D0, which was when the animals received an intravaginal device containing 1g of progestogen and an intramuscular application (im) of 2mg of EB. After 8 days (D8), the device was removed and 500g of cloprostenol (im) was administered to all females. Then, the animals were randomly divided into two treatments: BG Group (n = 52) and CG Group (n = 56). The CG animals received 1mg of ECP (im) as the ovulation inducer at the time of device removal, while BG Group cows received 1mg of EB (im) 24 h later (D9). TAI occurred at D10. After device removal, ultrasound

Os diversos estudos sobre manipulação do ciclo estral culminaram com o desenvolvimento de protocolos de sincronização do estro e da ovulação, a ponto de se definir um momento ótimo para a inseminação artificial. A indução da ovulação é parte primordial para a determinação do momento da IATF. Dessa forma, estudar quais hormônios e como eles se comportam permite compreender melhor esse processo fisiológico e, ainda, manipulá-lo de forma eficiente. O objetivo do presente estudo foi comparar o uso de benzoato de estradiol (BE) e cipionato (ECP) em vacas Girolando submetidas à inseminação artificial em tempo fixo (IATF). As ovulações de 108 vacas Girolando foram sincronizadas e no início do tratamento, D0, os animais receberam um dispositivo intravaginal contendo 1g de progestágeno e uma aplicação intramuscular (im) de 2mg de BE. No D8, o dispositivo foi removido e 500g de cloprostenol (im) foram administrados a todas as fêmeas. Depois disso, os animais foram divididos aleatoriamente em dois tratamentos: Grupo GB (n = 52) e Grupo GC (n = 56). Os animais do Grupo GC receberam 1mg de ECP (im) como indutor de ovulação no momento da retirada do dispositivo, enquanto as vacas do Grupo GB receberam 1mg de BE (im) 24 horas depois (D9). IATF ocorreu em D10. Após a remoção do dispositivo, as avaliações ultrassonográficas foram realizadas a cada 12 horas até a ovulação. Os parâmetros reprodu

Comparison of estradiol benzoate and cypionate in Girolando cows submitted to a timed artificial insemination / Comparação do benzoato e do cipionato de estradiol em vacas Girolando submetidas à Inseminação Artificial em Tempo Fixo

The various studies on the manipulation of the estrous cycle culminated in the development of estrous and ovulation synchronization protocols, to the point of defining an optimum moment for artificial insemination. The induction of ovulation is a primordial part for the determination of the moment of the TAI, so to study which hormones and how they behave allows a better understanding of this physiological process and, to manipulate it efficiently. The aim of the present study was to compare the use of estradiol benzoate (EB) and cypionate (ECP) as ovulation inducer in Girolando cows submitted to Timed Artificial Insemination (TAI). Ovulations of 108 Girolando cows were synchronized and the initial day of treatment, recorded as D0, which was when the animals received an intravaginal device containing 1g of progestogen and an intramuscular application (im) of 2mg of EB. After 8 days (D8), the device was removed and 500µg of cloprostenol (im) was administered to all females. Then, the animals were randomly divided into two treatments: BG Group (n = 52) and CG Group (n = 56). The CG animals received 1mg of ECP (im) as the ovulation inducer at the time of device removal, while BG Group cows received 1mg of EB (im) 24 h later (D9). TAI occurred at D10. After device removal, ultrasound evaluations were performed every 12 h up to ovulation. The following reproductive parameters were evaluated: interval from intravaginal device removal to ovulation - IDO (hours); interval from ovulation to TAI-IOT (hours); diameter of the largest follicle at intravaginal device removal (mm); maximum diameter of the DF (mm) at D10; the dominant follicle growth rate (mm/day); synchronization rate - SR (%); ovulation rate - OR (%) and PR - pregnancy rate (%). Only the ovulation rate presented a statistical difference (p<0.05). In conclusion, despite the ovulation rate difference, both estradiol esters administered were effective and presented similar pregnancy rates in Girolando cows submitted to TAI.

Os diversos estudos sobre manipulação do ciclo estral culminaram com o desenvolvimento de protocolos de sincronização do estro e da ovulação, a ponto de se definir um momento ótimo para a inseminação artificial. A indução da ovulação é parte primordial para a determinação do momento da IATF. Dessa forma, estudar quais hormônios e como eles se comportam permite compreender melhor esse processo fisiológico e, ainda, manipulá-lo de forma eficiente. O objetivo do presente estudo foi comparar o uso de benzoato de estradiol (BE) e cipionato (ECP) em vacas Girolando submetidas à inseminação artificial em tempo fixo (IATF). As ovulações de 108 vacas Girolando foram sincronizadas e no início do tratamento, D0, os animais receberam um dispositivo intravaginal contendo 1g de progestágeno e uma aplicação intramuscular (im) de 2mg de BE. No D8, o dispositivo foi removido e 500µg de cloprostenol (im) foram administrados a todas as fêmeas. Depois disso, os animais foram divididos aleatoriamente em dois tratamentos: Grupo GB (n = 52) e Grupo GC (n = 56). Os animais do Grupo GC receberam 1mg de ECP (im) como indutor de ovulação no momento da retirada do dispositivo, enquanto as vacas do Grupo GB receberam 1mg de BE (im) 24 horas depois (D9). IATF ocorreu em D10. Após a remoção do dispositivo, as avaliações ultrassonográficas foram realizadas a cada 12 horas até a ovulação. Os parâmetros reprodutivos avaliados foram: intervalo entre a retirada do dispositivo intravaginal de P4 e a ovulação- IRD (horas); intervalo entre a ovulação e a IATF- IOI (horas); diâmetro do maior folículo na retirada do dispositivo intravaginal de P4 (mm); taxa de crescimento do FD-TCFD (mm/dia); taxa de sincronização - TS (%); taxa de ovulação- TO (%) e taxa de concepção - TC (%). Apenas a taxa de ovulação apresentou diferença estatística (p<0.05). Em conclusão, apesar da diferença na taxa de ovulação, ambos os ésteres de estradiol administrados foram eficazes e apresentaram taxas de prenhez semelhantes em vacas Girolando submetidas a IATF.

Information Sources and Decision-Making in Neurosurgery: Results of a Survey of Members of the Brazilian Neurosurgery Society

Introduction In all surgical disciplines, including neurosurgery, there are questions about the level of evidence supporting surgical practices and the mechanisms and adequacy of knowledge translation. Objectives To assess the perception of Brazilian neurosurgeons of information sources and decision-making mechanisms related to their medical practices. Methods An online questionnaire was sent to the 2,400 members of the Brazilian Neurosurgical Society. Results A total of 32% of the neurosurgeons completed the questionnaire, 53% had more than 10 years experience, 67% had worked in public hospitals, 34% had performed spine surgeries, and 30% had performed brain tumor surgeries. The therapeutic decisions were based mostly on internship learning (54%) and personal professional experience (52%). The most common information sources were scientific abstracts (53%) and the Internet (47%). A total of 89% believed that evidence-based medicine was relevant, 93% believed protocols or guidelines were necessary, and 74% subscribed to a medical journal. Nonetheless, only 43% had protocols implemented in their services, 93% highly valued a surgeon's personal experience, and 63% showed little familiarity with the interpretation of scientific concepts in the literature. Among the respondents, 83% were willing to try an innovative treatment alternative if it was shown to improve clinical outcomes and reduce severe complications. Conclusions The disparity in the responses highlights the need to implement recommendations that improve decision-making mechanisms.

Introdução Em todas as disciplinas cirúrgicas, incluindo a neurocirurgia, existem questões sobre o nível de evidência que apoia as práticas cirúrgicas e os mecanismos e adequação da translação do conhecimento. Objetivos Avaliar a percepção de fontes de informação e mecanismos de tomada de decisão dos neurocirurgiões brasileiros em relação às práticas médicas. Métodos Um questionário on-line foi enviado aos 2.400 membros da Sociedade Brasileira de Neurocirurgia. Resultados Um total de 32% dos neurocirurgiões preencheram o questionário, 53% tinham mais de 10 anos de experiência, 67% trabalharam em hospitais públicos, 34% realizaram cirurgia de coluna, e 30%, de cérebro. As decisões terapêuticas basearam-se principalmente no aprendizado de estágio (54%) e na experiência profissional pessoal (52%). As fontes de informação mais comuns foram resumos científicos (53%) e a Internet (47%). Um total de 89% acreditava que a medicina baseada em evidências era relevante, 93% acreditavam que protocolos ou diretrizes eram necessários, e 74% tinham assinaturas de uma revista médica. No entanto, apenas 43% apresentaram protocolos implementados em seus serviços, 93% valorizaram a experiência pessoal de um cirurgião, e 63% mostraram pouca familiaridade com a interpretação de conceitos científicos na literatura. Entre os respondentes, 83% estavam dispostos a tentar uma alternativa de tratamento inovador se este demonstrasse melhorar os resultados clínicos e reduzir as complicações graves. Conclusões A disparidade nas respostas destaca a necessidade de implementar recomendações que melhorem os mecanismos de tomada de decisão.

Fatores ligados à doadora que influenciam na produção de embriões in vitro (PIVE) / Factors associated to the donor influencing the production of embryos in vitro (PIVE)

A produtividade dos rebanhos bovinos, seja de corte ou de leite, tem sido ampliada consideravelmenteatravés do aperfeiçoamento das biotécnicas de manejo reprodutivo. Entre estas, a produção in vitro (PIVE) deembriões tem sido utilizada com o objetivo de se produzir um maior número de descendentes por fêmea doadora,aumentando a vida útil desta. No entanto, apesar dos enormes avanços nos últimos anos, esta biotécnica aindaapresenta grandes limitações, pois diversos fatores podem interferir nos resultados finais, tornando viável ou nãosua implementação a nível comercial. O objetivo deste trabalho de revisão é apontar algumas fontes de variaçãoligadas à doadora na produção in vitro de embriões bovinos.

Productivity of livestock cattle, either beef or milk, has been expanded greatly through the improving ofreproductive biotechnologies. Among these, in vitro production (EIVP) of embryos have been used in order togenerate a larger number of offspring per female, extending the life cycle of them. However, despite the greateradvances in most recent years, this biotech still has major limitations, because many factors may interfere on thefinal results, making feasible or not their implementation on a commercial level. The aim of this review ishighlight some sources of variation for in vitro production of embryos in cattle.

Produção in vitro (PIV) de embriões em bovinos / In vitro embryo production in cattle

A produção in vitro de embriões (PIV) é uma biotécnica importante para exploração do potencialgenético de fêmeas bovinas e tem sido utilizada em escala comercial no Brasil e no mundo. A PIV envolve asetapas de coleta, maturação, fecundação e cultivo in vitro sendo que a eficiência das etapas de maturação efecundação in vitro não difere daquela obtida in vivo. No entanto, o cultivo in vitro continua sendo a etapa queapresenta a menor eficiência sendo que, em média, apenas 30% dos oócitos maturados in vitro se desenvolvemao estádio de blastocisto. Adicionalmente, os blastocistos produzidos in vitro diferem daqueles produzidos invivo, apresentando menores taxas de prenhez e sendo menos tolerantes à criopreservação. Portanto, o objetivo destarevisão é realizar uma abordagem atualizada das principais etapas da produção in vitro de embriões bovinos.

The in vitro embryo production (IVP) is a major tool for exploration of the genetic potential of cowsand has been used in commercial scale in Brazil and worldwide. The IVP technique involves the steps ofcollecting, maturation, fertilization and in vitro culture and the efficiency of the steps of maturation andfertilization in vitro does not differ from that obtained in vivo. However, the in vitro culture continues to be thestep that has the lowest efficiency and, on average, only 30% of in vitro matured oocytes develop to blastocyststage. In addition, in vitro produced blastocysts differ from those produced in vivo, with lower pregnancy ratesand are less tolerant to cryopreservation. Therefore, the aim of this review is to perform an updated approach tothe main steps of in vitro production of bovine embryos.

Parâmetros genéticos de características reprodutivas em bovinos de corte e leite / Genetic parameters of reproductive traits in beef and dairy cattle

O melhoramento genético em gado de corte e de leite é uma prática que vem sendo explorada eanalisada por muitos pecuaristas e estudiosos da área, com o intituito de se aperfeiçoar os indicadores dossistemas de produção a cada geração, a fim que se possa obter médias de características superiores com oavançar dos programas de melhoramento. No entanto, para se obter máxima eficiência de produção, torna-senecessário conhecer e melhorar os componentes genéticos das características reprodutivas, pois tem impactodireto na eficiência e produtividade do rebanho. O objetivo desta revisão é abordar os resultados de estudosrelacionados aos parâmetros genéticos para as características reprodutivas em bovinos de corte e de leite.

Genetic improvement in beef and dairy cattle is an activity that has been explored and analyzed bymany farmers and researchers in the livestock area, with aid to improve the parameters of production systems ineach generation in order to get averages of superior traits with the advance of genetic improvement programs.However, in order to find a maximum production efficiency, it is necessary to know and improve the geneticcomponents of reproductive traits, since it has direct impact on the efficiency and productivity of the herd. Theaim of this review is showing some results of studies regarding to genetic parameters for reproductive traits inbeef and dairy cattle.

Fatores ligados à doadora que influenciam na produção de embriões in vitro (PIVE) / Factors associated to the donor influencing the production of embryos in vitro (PIVE)

A produtividade dos rebanhos bovinos, seja de corte ou de leite, tem sido ampliada consideravelmenteatravés do aperfeiçoamento das biotécnicas de manejo reprodutivo. Entre estas, a produção in vitro (PIVE) deembriões tem sido utilizada com o objetivo de se produzir um maior número de descendentes por fêmea doadora,aumentando a vida útil desta. No entanto, apesar dos enormes avanços nos últimos anos, esta biotécnica aindaapresenta grandes limitações, pois diversos fatores podem interferir nos resultados finais, tornando viável ou nãosua implementação a nível comercial. O objetivo deste trabalho de revisão é apontar algumas fontes de variaçãoligadas à doadora na produção in vitro de embriões bovinos.(AU)

Productivity of livestock cattle, either beef or milk, has been expanded greatly through the improving ofreproductive biotechnologies. Among these, in vitro production (EIVP) of embryos have been used in order togenerate a larger number of offspring per female, extending the life cycle of them. However, despite the greateradvances in most recent years, this biotech still has major limitations, because many factors may interfere on thefinal results, making feasible or not their implementation on a commercial level. The aim of this review ishighlight some sources of variation for in vitro production of embryos in cattle.(AU)

Parâmetros genéticos de características reprodutivas em bovinos de corte e leite / Genetic parameters of reproductive traits in beef and dairy cattle

O melhoramento genético em gado de corte e de leite é uma prática que vem sendo explorada eanalisada por muitos pecuaristas e estudiosos da área, com o intituito de se aperfeiçoar os indicadores dossistemas de produção a cada geração, a fim que se possa obter médias de características superiores com oavançar dos programas de melhoramento. No entanto, para se obter máxima eficiência de produção, torna-senecessário conhecer e melhorar os componentes genéticos das características reprodutivas, pois tem impactodireto na eficiência e produtividade do rebanho. O objetivo desta revisão é abordar os resultados de estudosrelacionados aos parâmetros genéticos para as características reprodutivas em bovinos de corte e de leite.(AU)

Genetic improvement in beef and dairy cattle is an activity that has been explored and analyzed bymany farmers and researchers in the livestock area, with aid to improve the parameters of production systems ineach generation in order to get averages of superior traits with the advance of genetic improvement programs.However, in order to find a maximum production efficiency, it is necessary to know and improve the geneticcomponents of reproductive traits, since it has direct impact on the efficiency and productivity of the herd. Theaim of this review is showing some results of studies regarding to genetic parameters for reproductive traits inbeef and dairy cattle.(AU)