298 resultados para sêmen congelado
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Pós-graduação em Medicina Veterinária - FMVZ
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The aim of this study was to evaluate the association between cryoprotectants little studied in Brazil such as dimethylformamide and trehalose amid thinner, using protocols of fast and slow defrosting. Three adult Labrador Retrievier male, healthy dogs, weekly submitted to one semen collection during five-weeks period, were used. The base diluent medium used in this study was tris-citrate added with 3% of dimethylformamide + 3% glycerol (D1), 3% dimethylformamide and trehalose (D2) and 4% glycerol (D3). At defrosting, half of the semen samples from each diluent medium was defrosted by rapid method in water-bath at 75 °C for seven minutes, followed by a new immersion at 37 °C for 1 minute. The other half of the samples was defrosted by slow method, in water-bath at 37 °C for 1 minute. The semen was evaluated for sperm progressive motility and vigor, besides membrane integrity. For this, the semen samples were submitted to either hyposmotic and membrane integrity tests of the plasmatic membrane and acrosome (fluorescence). The results indicated that the use of glycerol as cryoprotector in TRIS diluter provides greater efficacy in cryopreserving spermatozoa of the canine species, when compared to dimethylformamide associated with trehalose or glycerol.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Pós-graduação em Biotecnologia Animal - FMVZ
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Ciência e Tecnologia Animal - FEIS
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The acceptance of biotechnology for the most equine breeders association had a significant effect in the horse industry, gaining popularity around the world, because the increasing on the genetic gain, allowing the use of sub fertile mares and stallions with high genetics value on reproduction. The embryos in vitro production of human and cattle has been used with success, however in vitro embryo production is not efficient in the horse, as oocyte transfer (OT) and intracytoplasmatic sperm injection (ICSI). The oocyte transfer has been used especially in subfertile old mares presenting reproductive pathologies as: endometrite, cervical and uterine adhesions, blocked oviduct, perineal laceration and ovulation failures. During oocyte recovery process, the oocytes must be collected from immature follicles that need be matured in vitro or in vivo matured oocytes from pre-ovulatory follicles through the transvaginal aspiration guided by ultrasound. The recovered oocyte is transferred to a previously inseminated recipient mare, through the flank laparotomy. The intracytoplasmatic sperm injection (ICSI) is a procedure of in vitro fertilization that needs only one sperm that is aspirated and injected inside the oocyte. The oocytes used, can be from mature and immature follicles. Fresh, cooled and frozen semen can be used, because the procedure not requires a functional sperm. The use of Piezo drill resulted in a breakthrough the pellucid zone, allowing the vibration per minute provided in the sperm injection pipette, a major result of cleaved oocytes, due to a better sperm injection in the oocyte. The embryo transfer can be straight inside the oviduct, as also transcervical transferred after embryo culture produced in vitro. In conclusion both procedures (OT and ICSI) are effective to be used on equine assisted reproduction, getting results even lower than expected, but satisfactory from animal genetically superior
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With the increasing development of the brazilian sheep production, the producer was forced to achieve higher production rates. The use of artificial insemination has been shown as an important biotechnological tool in animal breeding. Among the various existing techniques, the superficial cervical insemination with fresh semen is demonstrating fertility rates between 70 and 80% (AISEN, 2008), in addition to its applicability, it does not require sophisticated equipment or manpower to highly specialized implementing these plans greater possibility in your job to maximize reproduction and greater dissemination of superior genetic material on the property. This study aims to address aspects of artificial insemination with fresh semen in sheep and its applicability in commercial herds biotechnology as a tool in assisted reproduction
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It is a fact that Brasil has a featured position in the equine market due to the size and the high quality of its squad. To keep the competitivity, the reproduction biotechnologies have a big and important role. The cryopreservation of stallion semen, for example, generates innumerous advantages, which includes: larger number of obtained doses, storing genetic material for undetermined time, using the semen of a good stallion even after its dead or any other event that makes both semen collection and mating impossible, etc. In this context, the cryopreservation of epididymal sperm, has been seen as a promising technique in equine reproduction. The epididymal cauda has a significant quantity of fertile spermatozoa and this ensures a huge store of cells in cases of unexpected accidents, which can early interrupt with the reproductive life of a stallion. Lots of studies are being developed using the cryopreservation of stallion epididymal sperm. These studies permit the propagation of high quality genetic material and make possible for the stallion owner to opt for a final semen collect in unexpected circumstances
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Methods of semen cryopreservation allow changes in spermatic cells, such as damage in plasma and acrossomal membrane and modifications in mitochondrial function due to a disorder in the lipidic bilayer. For effective oocyte fertilization, spermatozoa require functional competent membranes, and intact organelles, acrosome and DNA. However, most laboratory methods used to evaluate semen quality are not highly correlated with fertilizing capacity. The discovery of a variety of fluorochromes and compounds conjugated to fluorescent probes has enabled an accurate assessment of the viability, integrity and function of spermatozoa. Among the most used probes that label the various compartments of the sperm cell there are the membrane impermeable fluorescent dyes to test the membrane integrity, as well as acylated dyes that pass the intact membrane. For the acrossomal integrity the most commonly used method is lectins labeled by a fluorescent probe. The acrosome reaction and spermatic capacitation is detected by the evaluation of membrane architecture and disorder of lipids in plasma membrane. Mitochondrial function can be determined using markers for their aerobic activity. The DNA status of spermatozoa has been determined using the metachromatic properties of Acridine Orange, and the DNA fragmentation can also be assessed by TUNEL assay. Finally, DNA condensation is analyzed using a single cell DNA gel electrophoresis assay that indicates DNA compactation. This monograph aims to compile the various tests used to detect damaged spermatozoa under cryopreservation methods, searching for improve the predictive value of semen analysis with the intention of a successful conception
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Pós-graduação em Medicina Veterinária - FCAV
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Pós-graduação em Medicina Veterinária - FCAV
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Pós-graduação em Medicina Veterinária - FCAV
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Pós-graduação em Medicina Veterinária - FCAV
Características seminais e resfriamento de sêmen de tamanduá (Myrmecophaga tridactyla) de vida livre
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)