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1.
Anim Reprod Sci ; 212: 106232, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31864498

RESUMO

Although combining of eCG and hCG administrations is known to enhance LH-like actions, there have been few studies where there was comparison of the effects of treatment of anestrous ewes with eCG and hCG and eCG alone. In Experiment 1, 18 ewes in seasonal anestrus were administered an intravaginal device (IVD) containing medroxyprogesterone acetate for 12 days, and at the time of IVD removal (D0), were allocated into the following groups (n = 6/group): no further treatment (control); 400 IU eCG (eCG); or 400 IU eCG and 200 IU hCG (eCG + hCG). There was greater ovarian follicular growth in the groups treated with gonadotropins, compared to the control, and there were greater progesterone concentrations in the eCG + hCG group on D9 (P < 0.05). In Experiment 2, 66 ewe lambs were assigned to the same treatment groups described for Experiment 1, and subsequently there was natural mating with rams. There was a greater rate of behavioral estrous manifestation in the eCG (88.5 %; 23/26) and eCG+hCG (85.2 %; 23/27), than control (30.8 %; 4/13; P < 0.05) group. Pregnancy rate was also greater in the eCG (34.6 %; 9/26) and eCG+hCG (18.6 %; 5/27) than control (0 %; 0/13; P < 0.05) group, whereas conception rate, considering only ewe lambs that were mated, was only greater in the eCG group. Although there were greater progesterone concentrations 9 days after treatment in the eCG+hCG group, there was no difference in follicular growth in anestrous ewes, nor was there an effect on estrous behavior manifestation and pregnancy rates in ewe lambs, compared to treatment with only eCG.

2.
Cryo Letters ; 40(3): 193-199, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31095669

RESUMO

BACKGROUND: Automated equipment with customized freezing curves can be used to cryopreserve ram sperm, but none is considered a standard. OBJECTIVE: This study compared the post-thawing quality of ram sperm frozen using a conventional freezing curve and two controlled-rate curves. MATERIALS AND METHODS: Six ejaculates were collected from four rams (n = 24). In the conventional curve (110 min), sperm was cooled at -0.3 to -0.5°C min-1 until 5°C, stabilized for 60 min and exposed to liquid nitrogen (LN2) vapor for 10 min (-80°C) before submersion. The slow-customized (SC) curve (126.2 min) used a rate of -0.25°C min-1 until 5°C, stabilization for 60 min and a rate of -20°C min-1 until -120°C before immersion in LN2. Rates for the fast-customized (FC) curve (75 min) were: -0.3°C min-1 until 5°C; -3°C min-1 until -10°C; -5°C min-1 until -35°C; and -4°C min-1 until immersion in LN2 (-43°C). RESULTS: Velocity in a straight line and beat-cross frequency were lower for spermatozoa frozen with the FC than with the conventional curve (P < 0.05). The FC curve resulted in more membrane and acrosome damages than the other curves (P < 0.05). Mitochondrial membrane potential was lower with the SC than with the other curves (P < 0.05). CONCLUSION: The conventional curve was more efficient than both tested automated freezing curves. The FC curve may be an alternative to the SC curve due to the shorter processing time.


Assuntos
Criopreservação/veterinária , Preservação do Sêmen/veterinária , Motilidade Espermática , Espermatozoides/fisiologia , Animais , Congelamento , Masculino , Ovinos
3.
Anim Reprod Sci ; 205: 150-155, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31076217

RESUMO

As oocytes and embryos of pigs have greater lipid content in the cytoplasm than those of other species, supplementation of the medium for in vitro maturation (IVM) of oocytes with omega-3 polyunsaturated fatty acids (PUFA) may help to improve embryo development. This study was conducted to evaluate effects of the inclusion of the docosaexaenoic (DHA) and of the eicosapentaenoic acids (EPA) in the IVM medium on the development of pig oocytes and on the lipid content of oocytes and embryos. In all experiments, control media consisted of porcine follicular fluid and oocytes were activated through parthenogenesis. In Experiment 1, there were four treatments for each PUFA: one control; and three treatments including EPA or DHA in the IVM medium at 12.5 µM, 25.0 µM and 50.0 µM). In Experiment 2, inclusion of 50 µM DHA was compared against the control. Cleavage rates in the IVM medium including 12.5 µM EPA and blastocyst development rates in media at any EPA concentration were less than for the control in Experiment 1 (P < 0.05). Compared to the control, inclusion of 50 µM DHA in the IVM medium was related to greater cleavage rates and greater number of embryo cells, in Experiment 1, and lesser lipid content in oocytes after 22 and 44 h and in embryos after 7 days, in Experiment 2 (both P < 0.05). Addition of DHA in the IVM medium may benefit the development of pig oocytes, but EPA appears to be cytotoxic.


Assuntos
Ácidos Docosa-Hexaenoicos/farmacologia , Ácido Eicosapentaenoico/farmacologia , Embrião de Mamíferos/química , Técnicas de Maturação in Vitro de Oócitos/veterinária , Oócitos/efeitos dos fármacos , Suínos/embriologia , Animais , Ácidos Docosa-Hexaenoicos/administração & dosagem , Relação Dose-Resposta a Droga , Ácido Eicosapentaenoico/administração & dosagem , Feminino , Metabolismo dos Lipídeos , Partenogênese , Suínos/fisiologia
4.
Cryo Letters ; 38(3): 187-193, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28767741

RESUMO

BACKGROUND: Xanthan gum is used as thickener in media to preserve food products, having cryoprotectant and antioxidant properties that may be relevant for sperm cryopreservation. OBJECTIVE: To evaluate the effects of adding xanthan gum to freezing extenders on post-thawing quality and oxidant activity of ram sperm. METHODS: Ejaculates from seven rams extended TRIS-egg yolk-glycerol were split in three treatments including xanthan gum (0.15%; 0.20%; and 0.25%) and a control with no xanthan gum. RESULTS: After thawing, motility and production of reactive oxygen species (ROS) with 0.20% and 0.25% xanthan gum were lower than for the control (P < 0.05), but mitochondrial functionality and integrity of membrane, acrosome and DNA did not differ (P > 0.05). Xanthan gum at 0.20% and 0.25% may be an efficient antioxidant for frozen-thawed ram sperm, due to the reduction in ROS production.


Assuntos
Antioxidantes/farmacologia , Criopreservação/métodos , Polissacarídeos Bacterianos/farmacologia , Preservação do Sêmen/métodos , Animais , Crioprotetores/farmacologia , Masculino , Ovinos , Motilidade Espermática/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos
5.
Reproduction ; 153(5): 577-587, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28246309

RESUMO

The method of transportation and the conditions imposed on the ovarian tissue are pivotal aspects for the success of ovarian tissue cryopreservation (OTC). The aim of this study was to evaluate the effect of the size of the ovarian tissue (e.g. whole ovary, biopsy size and transplant size) during different times of storage (0, 6, 12 and 24 h) on the structural integrity of equine ovarian tissue transported at 4°C. Eighteen pairs of ovaries from young mares (<10 years old) were harvested in a slaughterhouse and processed to simulate the fragment sizes (biopsy and transplant size groups) or kept intact (whole ovary group) and stored at 4°C for up to 24 h in α-MEM-enriched solution. The effect of the size of the ovarian tissue was observed on the morphology of preantral follicles, stromal cell density, DNA fragmentation and mitochondrial membrane potential. The results showed that (i) biopsy size fragments had more morphologically normal preantral follicles after 24 h of storage at 4°C; (ii) mitochondrial membrane potential was the lowest during each storage time when the whole ovary was used; (iii) DNA fragmentation rate in the ovarian cells of all sizes of fragments increased as storage was prolonged and (iv) transplant size fragments had increased stromal cell density during storage at cool temperature. In conclusion, the biopsy size fragment was the best to preserve follicle morphology for long storage (24 h); however, transportation/storage should be prior determined according to the distance (time of transportation) between patient and reproduction centers/clinics.


Assuntos
Criopreservação/veterinária , Folículo Ovariano/citologia , Ovário/citologia , Animais , Criopreservação/métodos , Criopreservação/normas , Feminino , Cavalos , Compostos Orgânicos , Folículo Ovariano/fisiologia , Ovário/fisiologia , Temperatura Ambiente , Fatores de Tempo , Transportes
6.
Arq. bras. med. vet. zootec ; 68(5): 1309-1315, set.-out. 2016. tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-827890

RESUMO

The effects of ß-mercaptoethanol (BME) and cysteine on the viability and oxidative activity of ram sperm after thawing and on development in vitro and viability of vitrified sheep embryos were evaluated. Ejaculates from four rams were pooled and extended, composing six treatments: no antioxidants; 2mM BME; 5mM BME; 2mM BME and 5mM cysteine; 5mM BME and 5mM cysteine; and 5mM cysteine. Sperm motility, membrane and acrosome integrity, mitochondrial functionality, production of reactive oxygen species and total antioxidant capacity were similar across treatments (P>0.05). A medium with no antioxidant presented cleavage and blastocyst development rates (60.3% and 33.6%, respectively) similar (P>0.05) to those of a medium with 50µM BME and 600µM cysteine (64.3% and 36.6%, respectively). Post-thawing viability of vitrified embryos was similar between media (P>0.05). Cysteine and BME had no influence on the post-thawing viability and oxidative activity of ram sperm and on the viability of vitrified sheep embryos.(AU)


Foram avaliados os efeitos do ß-mercaptoetanol (BME) e da cisteína sobre a viabilidade e a atividade oxidativa após o descongelamento do sêmen ovino e sobre o desenvolvimento in vitro e a viabilidade de embriões ovinos vitrificados. Ejaculados de quatro carneiros foram agrupados e diluídos, compondo seis tratamentos: sem antioxidantes; com BME 2mM; com BME 5mM; com BME 2mM e cisteína 5mM; com BME 5mM e cisteína 5mM; e com cisteína 5mM. Motilidade, integridade da membrana e do acrossoma, função mitocondrial, produção de espécies reativas de oxigênio e capacidade antioxidante total foram semelhantes entre os tratamentos (P>0,05). Em um meio sem antioxidantes, as taxas de clivagem e de desenvolvimento embrionário até blastocisto (60,3%, e 33,6%, respectivamente) foram semelhantes (P>0,05) às obtidas em um meio com BME 50µM e cisteína 600µM (64,3% e 36,6%, respectivamente). A viabilidade pós-descongelamento dos embriões vitrificados não diferiu entre os meios (P>0,05). O BME e a cisteína não influenciaram a viabilidade e a atividade oxidativa do sêmen ovino após o descongelamento e a viabilidade de embriões ovinos vitrificados.(AU)


Assuntos
Animais , Masculino , Antioxidantes/análise , Cisteína/análise , Mercaptoetanol/análise , Análise do Sêmen/veterinária , Ovinos/embriologia , Espécies Reativas de Oxigênio/análise , Preservação do Sêmen/veterinária , Vitrificação
7.
Reprod Domest Anim ; 50(6): 972-9, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26477334

RESUMO

Bull semen production centres (SPC) generally present satisfactory quality control for sperm processing, but non-standardized hygiene procedures. This study describes a Hazard Analysis and Critical Control Points (HACCP) system developed for bull SPC and subsequently implemented in a commercial SPC. After the identification of hazards at each step of semen processing and the determination of their risk and severity, monitoring and corrective procedures were designed to assess the system's efficiency. The HACCP system identified six microbiological hazards, 10 physical hazards, four chemical hazards and three critical control points. After the establishment of Good Processing Practices, Standard Operating Procedures and Standard Sanitizing Operating Procedures, the system was validated through an audit, to identify eventual failures and to define measures to correct them.


Assuntos
Bovinos , Análise de Perigos e Pontos Críticos de Controle , Medicina Reprodutiva/normas , Preservação do Sêmen/normas , Preservação do Sêmen/veterinária , Animais , Guias como Assunto , Masculino
8.
J Appl Microbiol ; 114(6): 1793-809, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23489977

RESUMO

AIMS: The goal of this study was to isolate and characterize a lactic acid bacteria (LAB) from donkey milk with potential beneficial properties. METHODS AND RESULTS: Lactic acid bacteria were isolated from donkey milk and identified based on physiological, biochemical and molecular methods. The isolate that presented highest bacteriocin potential (Lactobacillus plantarum LP08AD) was evaluated for the production of bacteriocin, including stability in the presence of various enzymes, surfactants, salts, pH and temperatures. Bactericidal effect of bacteriocin LP08AD on Listeria monocytogenes, Enterococcus faecium and Lactobacillus curvatus was shown for actively growing and stationary cells. Similar growth and bacteriocin production were observed when strain LP08AD was cultured in MRS broth at 30°C or 37°C. Bacteriocin LP08AD adhered at low levels on the producer cells (200 AU ml(-1) ). The presence of plantaricin W gene on the genomic DNA was recorded based on PCR. Good growth for strain LP08AD was recorded in MRS broth with pH from 5·0 to 9·0 and LP08AD grew well in the absence of oxbile or concentration below 0·8%. Lact. plantarum LP08AD was applied to the small intestinal epithelial polarized monolayers of H4, PSIc1 and CLAB and demonstrated low attachment ability on all cell lines studied, with values with a similar behaviour for cells from human and pig origin. CONCLUSIONS: Bacteriocin-producing Lact. plantarum LP08AD might be useful in the design of novel functional foods with potential probiotic or biopreservation properties. SIGNIFICANCE AND IMPACT OF THE STUDY: To the best of our knowledge, this is the first report on detection and characterization of bacteriocinogenic Lact. plantarum from donkey milk. The strain LP08AD shows to have potential beneficial properties, as demonstrated by the use of noncancerogenic cell lines.


Assuntos
Antibacterianos/biossíntese , Bacteriocinas/biossíntese , Lactobacillus plantarum/metabolismo , Animais , Antibacterianos/farmacologia , Bacteriocinas/genética , Bacteriocinas/farmacologia , Linhagem Celular , Equidae/microbiologia , Humanos , Lactobacillus plantarum/genética , Lactobacillus plantarum/isolamento & purificação , Leite/microbiologia , Probióticos , Suínos
9.
Arch Gynecol Obstet ; 287(4): 779-90, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23250342

RESUMO

PURPOSE: To compare the effectiveness and safety of controlled ovarian hyperstimulation (COH) using clomiphene citrate associated with gonadotropin and GnRH antagonist (CC + Ant) versus conventional COH without clomiphene citrate (Non-CC) for women undergoing assisted reproductive techniques (ART). METHODS: Systematic review and meta-analysis of randomized controlled-trials comparing CC + Ant versus non-CC. The last search was performed in Apr 13 2012. The following outcomes were retrieved from included trials and compared between CC + Ant versus non-CC: live birth, clinical pregnancy, ovarian hyperstimulation syndrome (OHSS), miscarriage, multiple pregnancy, endometrial thickness, total oocytes retrieved, MII oocytes retrieved, total gonadotropin used, and duration of COH. RESULTS: Seven trials (702 participants) were included. There was no significant difference in live birth (55/182 = 30.2 % vs. 47/181 = 26.0 %, p = 0.26, CC + Ant vs. non-CC, respectively), clinical pregnancy (98/346 = 28.3 % vs. 84/356 = 23.6 %, p = 0.12), miscarriage (6/35 = 17.1 % vs. 7/32 = 21.9 %, p = 0.42), endometrial thickness, and on the number of oocytes retrieved. There was a significant reduction in OHSS (1/216 = 0.5 % vs. 9/217 = 4.1 %, p = 0.01), consumption of gonadotropins, and duration of COH. CONCLUSIONS: Compared to non-CC, CC + Ant is likely to reduce the risk of OHSS, medication costs, and the duration of COH without evidence of effect on live birth and clinical pregnancy. More trials are still needed to improve the quality of the evidence. Future studies should evaluate women with PCOS or at increased risk of OHSS, quality of life, satisfaction with the treatment, total cost per live birth, and frequency of congenital anomalies.


Assuntos
Clomifeno/administração & dosagem , Fármacos para a Fertilidade Feminina/administração & dosagem , Hormônio Liberador de Gonadotropina/antagonistas & inibidores , Gonadotropinas/administração & dosagem , Indução da Ovulação/métodos , Feminino , Humanos , Síndrome de Hiperestimulação Ovariana/induzido quimicamente , Indução da Ovulação/efeitos adversos , Gravidez , Taxa de Gravidez , Resultado do Tratamento
10.
Food Chem Toxicol ; 50(5): 1399-404, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22386818

RESUMO

Lithothamnion calcareum is a red alga of the Corallinacea family whose main feature is the formation of calcium carbonate precipitate in its cell walls. L. calcareum is marketed as a nutritional supplement for calcium and other minerals in Brazil and other countries under the pharmaceutical name of Vitality 50+. In this study, gastroprotective and pre-clinical toxicity assays were performed on this product. Doses of 30, 120 and 480 mg/kg were used in the gastroprotective study on Wistar rats. A dose of 2000 mg/kg was used in the preclinical acute toxicity study and oral doses of 1000 and 2000 mg/kg were used in the subchronic toxicity evaluation. L. calcareum played no significant role in the protection of the rats' gastric mucosa, nor did it cause increase in gastric irritation. No impact on the acute toxicity test was identified. In the subchronic toxicity test, serum levels of albumin, total protein and calcium decreased, and creatinine levels increased, suggesting hypercalcemia and possible kidney damage associated with liver damage, given that the majority of these parameters were irreversible. Thus, this work aims to discuss the relationship of the high concentration of calcium in the product with the observed effects.


Assuntos
Extratos Vegetais/farmacologia , Extratos Vegetais/toxicidade , Rodófitas/química , Úlcera Gástrica/prevenção & controle , Animais , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Feminino , Masculino , Ratos , Ratos Wistar , Testes de Toxicidade Aguda , Testes de Toxicidade Subcrônica
11.
Anim Reprod Sci ; 126(3-4): 157-61, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21733646

RESUMO

Bull breeding soundness evaluation (BBSE) usually neglects the libido and mating ability evaluation. The internal artificial vagina (IAV) permits semen sampling, as well as mating ability evaluation. Few studies have been performed using IAV with young bulls and there are none with Bos indicus bulls. The present study evaluated sexual behavior, mating ability and semen quality in young Bos taurus (Devon) and B. indicus (Nellore) bulls using the IAV device. In the first experiment, 52 Devon bulls, 18-25 months old were observed, and the behavior and mating ability recorded over a 10-min period within a restrained mount-cow with an IAV inserted. In the second experiment, 20 Nellore bulls, 20-30 months old were evaluated over a 20 min period. Of the 52 Devon bulls, 45 (86.5%) had semen recovered with the IAV, 31 (69.0%) were considered satisfactory. Nellore bulls exhibited a different sexual behavior, with 10 bulls not showing any interest in the females. Four bulls demonstrated sexual interest only once, e.g., sniffing, two showed interest on more than one occasion, and four had more than two mounts or mounting attempts. None out of the Nellore bulls was collected with IAV. The IAV was an effective and welfare-promoting animal technology for the evaluation of semen quality and mating ability of B. taurus bulls. However, the IAV was not adequate for young Nellore bulls, probably due to their quiescent sexual behavior and delayed sexual maturity. Further studies are needed to evaluate the performance of the IAV for older Nellore bulls.


Assuntos
Cruzamento/métodos , Bovinos/fisiologia , Animais , Feminino , Masculino , Sêmen/fisiologia , Comportamento Sexual Animal/fisiologia , Vagina
12.
Reprod Domest Anim ; 43(3): 314-318, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18086255

RESUMO

Vitrification has been the method of choice for the cryopreservation of bovine oocytes, as rapid cooling decreases chilling sensitivity. The aim of this study was to determine the in vitro and in vivo survival and the viability of immature oocytes vitrified using super-cooled liquid nitrogen. Immature oocytes were randomly allocated to three groups: (i) non-vitrified control group, (ii) vitrified in normal (-196 degrees C) liquid nitrogen (LN(2)) and (iii) vitrified in super-cooled LN(2) (< or =-200 degrees C). Open-pulled glass micropipettes were used as vitrification containers. Immature oocytes were in vitro-matured, fertilized and cultured to the blastocyst stage. In vitro viability was assessed by cleavage and blastocyst rates on days 2 and 7 of culture respectively. Vitrified blastocysts derived from the immature vitrified oocytes were directly transferred to synchronous recipients. The in vitro embryo development of vitrified immature oocytes was not influenced by the LN(2) state. After direct transfer (one embryo per recipient) of 16 embryos obtained from immature vitrified oocytes (eight from each vitrified group), two healthy calves were born in each group. These results indicated that vitrification of immature bovine oocytes using glass micropipettes under normal or super-cooled LN(2), resulted in viable blastocysts and live calves following in vitro embryo production.


Assuntos
Bovinos/fisiologia , Criopreservação/veterinária , Transferência Embrionária/veterinária , Oócitos , Resultado da Gravidez/veterinária , Animais , Animais Recém-Nascidos , Blastocisto/efeitos dos fármacos , Blastocisto/fisiologia , Bovinos/embriologia , Criopreservação/métodos , Crioprotetores/farmacologia , Técnicas de Cultura Embrionária/veterinária , Transferência Embrionária/métodos , Feminino , Fertilização In Vitro/veterinária , Vidro , Microtúbulos , Oócitos/efeitos dos fármacos , Oócitos/fisiologia , Gravidez , Distribuição Aleatória
13.
Anim Reprod Sci ; 99(3-4): 377-83, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16870364

RESUMO

The aim of this study was to determine the influence of two ethylene glycol-based vitrification solutions on in vitro and in vivo survival after in-straw cryoprotectant dilution of vitrified in vitro-produced bovine embryos. Day-7 expanded blastocysts were selected according to diameter (> or = 180 microm) and osmotic characteristics and randomly assigned to one of three groups (i) VSa: vitrification in 40% EG+17.1% SUC+0.1% PVA; (ii) VSb: vitrification in 20% EG+20% DMSO; (iii) control: non-vitrified embryos. Vitrification was performed in hand-pulled glass micropipettes (GMP) and cryoprotectant dilution in 0.25 ml straws after warming in a plastic tube. Embryo viability was assessed by re-expansion and hatching rates after 72 h of IVC and by pregnancy rates after direct transfer of vitrified embryos. No differences in re-expansion rates were observed between vitrified groups after 24 h in culture (VSa=84.5%; VSb=94.8%). However, fewer VSa embryos (55.2%, P<0.05) hatched after 72 h than the VSb (75.8%) and control embryos (80.0%). To evaluate in vivo viability, vitrified embryos (VSa=20; VSb=21) were warmed under field conditions and individually transferred to synchronous recipients. Pregnancy rates (day 60) were similar between groups (VSa=20%; VSb=19%). Greater hatching rates occurred after 72 h of IVC for EG+DMSO than EG+SUC+PVA vitrification solutions. However, using a GMP vitrification container and in-tube warming, both solutions provided similar pregnancy rates after the in-straw cryoprotectant dilution and direct embryo transfer.


Assuntos
Blastocisto/efeitos dos fármacos , Bovinos/embriologia , Criopreservação/veterinária , Crioprotetores/farmacologia , Vidro , Animais , Blastocisto/fisiologia , Criopreservação/instrumentação , Transferência Embrionária/veterinária , Feminino , Fertilização In Vitro/veterinária , Gravidez
14.
Anim Reprod Sci ; 100(3-4): 364-70, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17156950

RESUMO

The influence of the timing for the ablation of dominant follicle(s) prior to superovulatory treatment, and its effect on ovarian follicular growth and embryo yield, still remain elusive in cattle. The present study was designed to evaluate the effects of: (1) the day of the estrous cycle, at mid-diestrus, for the onset of superstimulation of follicular development, (2) the presence or absence of large ovarian follicles (ovary status) and (3) the time of follicular ablation, in hours, prior to the superovulatory treatment, on the superovulatory response in cattle. From a total of 244 superovulatory treatments and embryo collections in nulliparous and multiparous females, 76 were conducted after follicular ablation using a simplified transvaginal puncture cannula. Results from the present study indicated that the presence of large palpable follicle(s) at the onset of superstimulation of follicular development markedly reduced the superovulatory response. In addition, follicular ablation at 0 h or at 24 h prior to the onset of the superstimulation treatment significantly increased the number of total viable embryos. However, superovulatory responses were not affected by the day of the estrous cycle for the onset of follicular superstimulation and by the animal category (heifers or cows). In conclusion, the ablation of palpable follicle(s) 24 h or immediately prior to the onset of gonadotropin treatment, from days 8 to 12 of the estrous cycle (day 0, behavioral estrus), increased the total number of transferable embryos per flushing in cattle.


Assuntos
Bovinos/fisiologia , Folículo Ovariano/fisiologia , Superovulação/fisiologia , Animais , Cloprostenol/farmacologia , Feminino , Hormônio Foliculoestimulante/farmacologia , Superovulação/efeitos dos fármacos , Fatores de Tempo , Vagina
15.
Cryobiology ; 45(1): 91-4, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12445553

RESUMO

The aim of this study was to evaluate the developmental capacity of immature bovine oocytes after vitrification with 20% ethylene glycol (EG)+20% dimethyl sulfoxide (Me(2)SO) and 0.5M sucrose (SUC), by open pulled straw (OPS) technology. The effect of treatment with cytochalasin D before vitrification was also examined. No differences were observed in cleavage and blastocyst rates among the group vitrified without cytochalasin D treatment (Vitri) (49.0% and 6.1%) and that with cytochalasin D treatment before vitrification (CDVitri) (46.4% and 3.6%), but both were lower (P<0.05) than the unvitrified control group (85.1 and 45.9%). Calves were obtained after transfer of fresh and vitrified blastocysts from the Vitri group and after transfer of vitrified blastocysts from the CDVitri group. Cytochalasin D treatment does not improve the development of immature bovine vitrified oocytes. The results show that a small proportion of immature oocytes vitrified with this technology are fully competent to produce blastocysts, which may be transferred immediately or vitrified before transfer, and go on to develop healthy offspring.


Assuntos
Criopreservação/veterinária , Oócitos , Resultado da Gravidez/veterinária , Animais , Animais Recém-Nascidos , Bovinos , Criopreservação/instrumentação , Criopreservação/métodos , Crioprotetores/farmacologia , Citocalasina D/farmacologia , Transferência Embrionária/veterinária , Desenvolvimento Embrionário e Fetal , Feminino , Fertilização In Vitro/veterinária , Microtúbulos/efeitos dos fármacos , Oócitos/efeitos dos fármacos , Gravidez
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