Pacu embryos submitted to different cooling protocols

O objetivo deste trabalho foi avaliar a taxa de eclosão de larvas de pacu (Piaractus mesopotamicus), após o resfriamento dos embriões a -8oC durante seis horas, utilizando soluções crioprotetoras, para obter um protocolo de resfriamento para a espécie. Utilizaram-se 2.400 embriões em estádio de pós-gástrula, em sete tratamentos de soluções crioprotetoras, mais um controle, com três repetições, em delineamento inteiramente casualizado. Os crioprotetores etilenoglicol e geléia real foram inapropriados. A substituição de 50% da sacarose não produziu resultados positivos. A combinação metanol (9%) e sacarose (17,5%) possibilitou eclosão de 69,2%, sendo recomendada para o resfriamento a -8°C de embriões de pacu por seis horas.The objective of this work was to evaluate the percentage of hatching after cooling of pacu (Piaractus mesopotamicus) embryos at -8oC for six hours, treated with cryoprotectant solutions, to obtain a cooling protocol for the specie. There were 2.400 embryos in post-gastrula stage development, in seven cryoprotectants solutions and control with three replicates, in completely randomized design. Ethylene glycol and honey-jelly were inappropriate. The substitution of 50% sucrose did not produce positive results. The combination of methanol (9%) and sucrose (17.5%) performed 69.2% of hatching and is recommended for cooling of pacu embryos at -8 °C for six hours

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 of agricultural interest, especially bulls. However, cryopreservation can be harmful to sperm cells, with susceptibility to oxidative stress being one of the causes. The addition of antioxidants such as quercetin may inhibit and/or reduce such damage, 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.Material, Methods & Results: Three Brahman bulls in reproduction age and previously considered fit for reproduction were used. The semen samples were collected via the electroejaculation method, and the samples were homogenized to form pooled semen from three ejaculates, which was diluted in Tris-yolk egg-glicerol diluent medium. Quercetin was added to diluent, to final concentrations of 0, 5, 10, 15 and 20 μg.mL-1 in each group. The samples were kept frozen in straws of 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 superoxide radical production with a nitroblue tetrazolium test (NBT) and scanning spectrophotometry. By spermatic evaluation, the following 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 average path (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 (WOB = VAP/VCL), linearity (LIN, VSL:VCL) and straightness (STR, VSL:VAP). And by surface analysis through scanning electron microscopy (SEM). The NBT test demonstrated an increase in cell metabolism of approximately 40% up to the limit of 15 µg.mL-1 quercetin. The parameters of CASA pertaining to velocity (VCL, VSL, VAP) and as a consequence, wobble and linearity increased as a function of the quercetin concentration until 20 µg.mL-1, which was shown to be statistically significant. No significant morphological changes between groups were observed by the SEM technique.Discussion: The reduction of NBT indicates oxidative metabolism, being an indirect measure of the oxygen dependent activity of the cells, therefore the results demonstrate that quercetin supplementation increased the number of cells with high metabolic activity. Regarding the evaluation of CASA, according to the literature, some parameters are reliable estimates of the fertilization capacity of the human spermatozoon, among them, the VCL. In this study, all speeds were increased with Quercetin, including LCV, demonstrating its importance in supplementation in bovine seminal diluent. Scanning electron microscopy evaluates the structural morphology of the cell surface. As with previous results, in this study, all cells lost the acrosome. However, this type of damage was already expected in thawed spermatozoa. In addition, no other significant changes were observed in the morphology of the membrane or other parts of the sperm. In general, the results presented here suggest that the addition of quercetin to the seminal diluent before freezing improve spermatic quality, which manifests itself as faster spermatozoa and may higher fertilization rates

Comparação do sêmen de Curimbá (Prochilodus lineatus) induzido por extrato de hipófise de frango, coelho ou carpa

Foram selecionados 48 Curimbás (Prochilodus lineatus) e hipofisados com extrato de hipófise de frango (EHF), extrato de hipófise de coelho (EHCo) e o controle com extrato de hipófise de carpa (EHC). Os animais foram induzidos, aleatoriamente, com os tratamentos arranjados em um fatorial de três hormônios e três semanas. Animais tratados com EHF, EHC ou EHCo produziram, em média, 0,65, 0,45 e 0,20 mL de sêmen, respectivamente, havendo diferença (P;0,05) quando comparados com os machos induzidos com EHF. Prochilodus lineatus induzidos com EHF mostraram motilidade espermática progressiva superior (P;0,05) aos tratados com EHC ou EHF. Quanto ao vigor espermático, os machos responderam de forma semelhante (P>;0,05) para os três indutores utilizados, sendo em média, 2,75 pontos. De acordo com os resultados obtidos, conclui-se que o EHF apresentou eficiência semelhante ou melhor do que o tradicional EHC. Entretanto, o EHCo necessita de mais pesquisas, visando testar hipófise de animais mais idosos.Forty eight curimba (Prochilodus lineatus) were selected and hipophysed with broiler chicken hypophysis extract (BCHE), rabbit hypophysis extract (RHE) or carp hypophysis extract (CHE) as a control. The animals were randomly induced with treatments arranged in one factorial of three hormones and three weeks. Animals treated with BCHE, CHE and RHE produced an average of 0.65, 0.45 and 0.20 mL of semen, respectively. Therefore, difference (P;0.05) when compared with males induced with BCHE. Prochilodus lineatus induced with BCHE showed higher progressive spermatic motility (P;0.05) of animals treated with CHE or BCHE. Animals treated with BCHE, RHE or CHE had same spermatic vigor (P>;0.05), with an average of 2.75 points. According to these results it is possible to concluded that BCHE showed the same efficiency or it was even better than traditional CHE when used to induced males. However, more research effort with RHE is necessary, particulary with older animals hypophysis

DESEMPENHO REPRODUTIVO DE OVELHAS ALIMENTADAS COM DIETAS CONTENDO DIFERENTES NÍVEIS DE ENERGIA NO TERÇO INICIAL DA PRENHEZ

Após a sincronização de estro e cobertura, 120 fêmeas Santa Inês foram distribuídas em quatro tratamentos de Nutrientes Digestíveis Totais (NDT): 59,68%; 66,28%; 72,93%; e 79,39%, utilizando-se ração total, de 0 a 50 dias de gestação, para avaliar o índice de prenhez em função dos níveis energéticos da dieta e da taxa de glicose circulante, bem como a absorção embrionária em função da condição corporal (CC) e da taxa de glicose circulante no momento da cobertura. No dia da cobertura e a cada dez dias, foram coletados 5 mL de sangue para determinação imediata do teor de glicose e para dosar a progesterona circulante. A partir do 25º dia pós-cobertura, realizaram-se exames de ultrassonografia, para acompanhamento da gestação, visando avaliar perdas embrionárias. A taxa de perda embrionária foi correlacionada com os níveis energéticos das dietas e com os níveis de glicose circulante e, antes dos 20 dias, utilizaram-se os níveis sanguíneos de progesterona para estimar a prenhez. As fêmeas que apresentaram valores de progesterona acima de 1 ng/mL de plasma foram consideradas prenhas aos 20 dias. A mortalidade embrionária não foi influenciada (P˃0,05) pela taxa de glicose circulante das ovelhas, no dia da cobertura. A taxa de prenhez foi influenciada (P<0,05) pela CC das fêmeas no dia da cobertura, com maior índice de prenhez nas ovelhas com CC = 3. A glicose diminuiu com o aumento do peso e da CC, com as ovelhas mais pesadas e em melhor CC, apresentando maior probabilidade de mortalidade embrionária. Houve ganho de peso linear das ovelhas, de 0 a 50 dias pós-cobertura, em função do aumento dos níveis de energia da dieta. Recomenda-se cobrir ovelhas com maior taxa de glicose circulante, CC próxima a três e dieta com 59,68% de NDT, nos primeiros 50 dias de gestação