RESUMO
BACKGROUND: Bulls are of great importance in the productive chain and for this reason they should have a good semen quality. There is no doubt that sperm morphology is very important to bull fertility, although little is known about how exactly the abnormal morphologies may affect sperm functions. OBJECTIVES: To detail the morphological description of the aplastic midpiece defect (AMD), as well as to understand its consequences for male fertility based on membrane and acrosome status, mitochondrial membrane potential and DNA integrity parameters. MATERIALS AND METHODS: The bulls were divided into two groups: control, consisting of satisfactory potential breeders (n = 3); and AMD, consisting of unsatisfactory potential breeders with a high percentage of AMD (n = 3). Bulls were evaluated by the breeding soundness evaluation; five ejaculates were collected from each animal and analyzed by flow cytometry. RESULTS: Spermatozoa from AMD group exhibited lower sperm motility and vigor (p < 0.05). In addition, it also exhibited lower mitochondrial membrane potential (p < 0.05), a higher percentage of spermatozoa with DNA fragmentation (p < 0.05), lower acrosome and plasma membrane integrity (p < 0.05), and higher lipid bilayer sperm membrane disorganization (p < 0.05) in comparison with control bulls. DISCUSSION: These findings may be due to oxidative stress and a reduction of the energy production capacity in addition to an alteration in the structural composition of the sperm cell. Moreover, semen with a high percentage of AMD may also be undergoing apoptosis. CONCLUSION: Bulls with a high percentage of AMD in their semen are not suitable for reproduction. Furthermore, it suggests there is a putative genetic basis for this sperm defect.
Assuntos
Bovinos , Fertilidade , Espermatozoides/anormalidades , Animais , Masculino , Peça Intermédia do Espermatozoide/patologia , Espermatozoides/fisiologiaRESUMO
Objetivou-se com este trabalho observar as mudanças do parênquima testicular de acordo com o fotoperíodo e com a faixa etária dos animais por meio da ecotextura testicular e a viabilidade do uso do ultrassom na avaliação testicular. Foram utilizados 4 animais desde o 6° até o 13° mês de idade. Os exames ecográficos foram realizados a cada 15 dias para avaliar a ecotextura testicular. O parênquima testicular mostrou-se moderadamente ecogênico e homogêneo. Foi observado comportamento semelhante na ecotextura testicular durante o período de avaliação, sendo maior no 8º mês de idade, quando o volume testicular também foi maior; tais mudanças foram relacionadas com o fotoperíodo da região. A avaliação ultrassonográfica dos testículos mostrou-se um método eficiente, capaz de detectar as mudanças no parênquima testicular ao longo do tempo, e como ferramenta alternativa para diferenciação de condições normais e patológicas em caprinos...
The purpose of this study was to observe changes in the testicular parenchyma of male goats. Changes were observed in terms of goat age, evaluating the echotexture and ultrasound viability in the testicles. Four animals were used, ranging from six to 13 months of age. The echographic examinations were performed every 15 days to assess echotexture of the testicle. The testicular parenchyma appeared moderately echogenic and homogeneous. Similar results were observed in testicular echotexture during the evaluation period. The highest results appearing during the eighth month of age, when the testicular volume was also highest; such changes were related to the regional photoperiod. The ultrasound evaluation of the testicles was shown to be an effective method, ultimately capable of detecting changes in testicular parenchyma over time, being an alternative to differentiation normal and pathological conditions in goats...