Zinc Sulphate Turbidity as a Screening Test of Passive Transfer of Immunity in Newborn Foals

Background: Passive immunity acquired by colostrum ingestion is essential to prevent neonatal infections. Failure of passive transfer (FPT) of maternal immunity occurs in foals that fail to absorb enough immunoglobulins within 24 h after birth. Foals with FPT are at increased risk of infections and death. Serum samples from neonatal foals might be examined for FPT using the zinc sulphate turbidity (ZST) test. The aim of this study was to investigate the accuracy of the ZST test, performed at two different times after first suckling (12 and 18 h), to detect FPT in newborn foals. The effect of temperature on the turbidity intensity resulting from the ZST reaction was also investigated.Materials, Methods & Results: Blood samples were collected from 112 newborn foals at 12 h after the first colostrum intake. In 36 foals, additional serum samples were collected at 18 h after first colostrum intake. The serum samples were tested with the ZST test and, later, in the laboratory setting, the ZST test was repeated. The IgG levels were measured by single radial immunodiffusion (SRID), which was used as the reference method. The standard solution used for the interpretation of results had a turbidity corresponding to approximately 800 mg/dL of immunoglobulins (IgG). The mean IgG concentration measured at 12 and 18 h after the first colostrum intake was analyzed using the t-test for paired samples. Values of absorbance of ZST test under different temperatures were analyzed using a one-way analysis of variance, and means were compared using the Tukey test. The relationship between the temperature of the solution and absorbance was determined using the Pearson’s correlation coefficient. Based on SRID results, 12 foals (10.7%) had serum IgG concentration 0.05) between 12 h (943.9 ± 508.6 mg/dL) and 18 h (975.9 ± 525.6 mg/dL) after the first colostrum intake. The sensitivity values were 76.3% and 71.0% (P > 0.05) for tests performed at farm and laboratory, respectively. The specificity was higher (P < 0.05) for ZST tests performed at laboratory (94.6%) than at farms (73.0%). Twenty-nine of the 38 foals (76.3%) with IgG < 800 mg/dL were correctly detected using the ZST test at farms. There was a strong correlation (r = 0.92; P < 0.0001) between the temperature of the solution test and the degree of turbidity. The absorbance after the reaction of serum with zinc sulphate was similar between the temperatures of 30, 34 and 37ºC, which had higher values than 20 and 25ºC.Discussion: The ZST test can be performed at 12 h after the first suckling. The lower specificity of tests run at farms compared to laboratory resulted in more foals with false positive diagnosis. The main cause of false positives at farms was probably the low temperature of the zinc sulphate solution at the time of testing, delaying the reaction and underestimating the IgG concentration. This assumption was reinforced by the increased specificity observed when the test was repeated with the same serum samples under controlled temperature of a laboratory. Additionally, the positive correlation observed between the temperature and degree of turbidity confirms that the reaction is temperature dependent. In the Southern hemisphere, most Thoroughbred foals are born during winter, when room temperature is far below the ideal temperature for good performance of the ZST test. Therefore, the number of false positives will likely be reduced if tests are performed at the farms under adequate temperature of solution (between 30 and 37ºC). This will reduce the number of foals receiving unnecessary treatment

Pregnancy rates using frozen semen of Criollo stallions with glycerol or dimethylformamid as cryoprotectants

O índice de prenhez utilizando sêmen criopreservado de garanhões é variável e, além disso, algumas raças apresentam baixa congelabilidade. Foram inseminadas 104 éguas, divididas em dois experimentos, para avaliar a fertilidade do sêmen congelado de garanhões da raça Crioula (n=5), com 5% de dimetilformamida (DMF) ou 5% de glicerol (GLI), como crioprotetores. No Experimento I, as inseminações foram conduzidas pré-ovulação com sêmen fresco e criopreservado com DMF. No Experimento II, as éguas foram inseminadas pós-ovulação com sêmen fresco, DMF e GLI. As inseminações com sêmen congelado foram realizadas no ápice do corno uterino e as éguas do grupo controle foram inseminadas no corpo do útero com sêmen fresco. Para a avaliação dos índices de prenhez dos grupos, utilizou-se um ciclo estral/animal. O diagnóstico de gestação foi realizado por meio de ultrassonografia transretal no 15º dia pós-ovulação. A motilidade média pós-descongelamento foi de 40% e 20%, respectivamente, para o sêmen congelado com DMF e GLI (P<0,05). Todos os garanhões tiveram motilidade superior no pós-descongelamento quando se utilizou a DMF. No Experimento I, o índice de prenhez foi de 12% (5/42) e 62% (20/32), respectivamente, para DMF e sêmen fresco (P<0,0001). No Experimento II, o índice de prenhez foi de 70% (7/10; P<0,05) para o sêmen fresco, 40% para o congelado com DMF (4/10; P<0,05) e 10% com GLI (1/10). A inseminação com sêmen congelado realizada com controle folicular mais frequente apresentou os melhores resultados. A baixa motilidade dos espermatozoides pós-descongelamento foi atribuída ao GLI utilizado no Experimento II. A DMF pode ser utilizada como uma alternativa ao congelamento do sêmen de garanhões da raça Crioula.Pregnancy rates using stallions's frozen semen are variable; moreover, some breeds present low freezability. One hundred and four (104) mares were inseminated and separeted into two experiments to evaluate fertility of frozen semen's of Criollo stallions (n=5), with 5% of dimethylformamide (DMF) or 5% of glycerol (GLY) as cryoprotectants. In Experiment I, the inseminations were made during pre-ovulation with fresh and frozen semen with DMF. In Experiment II, the mares were inseminated during post-ovulation with fresh semen, DMF and GL. The inseminations with frozen semen were performed deep in the uterine horn ipsilateralis to the dominant follicle. Control mares were inseminated with fresh semen in the uterus. Only one estrus period per mare was used to evaluate the pregnancy rates of the groups. Pregnancy diagnosis through ultrasonography was performed on the 15th day post-ovulation. The mean post-thawing motility was 40% and 20%, respectively, for frozen semen with DMF and GLY (P<0.05). All stallions had higher post-thawing motility when using DMF. In Experiment I, pregnancy rates were 12% (5/42) and 62% (20/32), respectively for DMF and fresh semen (P<0.0001). In Experiment II, pregnancy rates were 40% (4/10), 10% (1/10) and 70% (7/10), respectively for DMF, GLY (P<0.05) and fresh semen (P 0.0001). Insemination with frozen semen performed with more frequent follicular control showed the best results. The low sperm motility after thawing was attributed to the GLY used in experiment II. The DMF can be used alternatively to Criollos Stallion's semen feezing

Desenvolvimento embrionário in vitro de oócitos bovinos mantidos em líquido folicular ou TCM-hepes

In order to evaluate the effect of a transport medium on the rate of in vitro embryonic development, 1381 Cumulus-oocyte Complexes (COC) were obtained by aspiration of 2-8mm diameter follicles witch were randomly divided in 4 treatment groups. The Control group was formed by oocytes matured in modified TCM-199 for 24h, incubated at 39°C and 5,00% CO2 with saturated humidity. The group 1 (WB24h), included oocytes matured in 1.0mL tubes containing TCM-HEPES (5.95mg/mL), in water bath (WB) at 39°C for 24h. The group 2 (FFb6C18h), included oocytes kept in bovine follicular fluid (FFb) for 6h at 30°C followed by a period of 18h maturation under the same conditions as the Control group and with the oocytes maintained in FFb followed by 18h IVM under the same conditions as the group 1, group 3 (FFb6WB18h). Fertilization was performed in FERT-TALP for 18h. Zygotes were cultured in SOFaaci under mineral oil within gasified bags. The cleavage rate differed (P&lt;0.05) between the Control and FFb6BM18h groups. However, there was no difference on the D7 and D9 blastocyst rates and on the percentage of blastocyst ecloded. It was concluded that it is possible to maintain the oocytes in FFb for 6h at 30°C before 18h IVM, or to proote the transport and maturation of the oocytes for 24h, in TCM-HEPES and water-bath at 39°C, without compromising embryonic development. The simplification of MIV showed in this experiment through of tubes (1.0mL) replete with TCM-HEPES and holding in water bath at 39°C, could be a viable and practice for the bovine programs of OPU/PIV.Complexos Cumulus-Oócito (CCO) bovinos foram divididos em 4 grupos para avaliar o seu comportamento durante a manutenção em LFb e maturação in vitro (MIV) em TCM-199 com ou sem Hepes. CCO MIV por 24h em TCM-199 em estufa a 39°C com 5,00% de CO2 (Controle) tiveram o seu desenvolvimento comparado ao de CCO MIV em tubos repletos de TCM-HEPES (5,95 mg/mL), em banho-maria (BM) a 39ºC por 24h (Grupo 1 - BM24h), ao de CCO mantidos em líquido folicular bovino (LFb), por 6h a 30ºC seguido de maturação por 18h nas mesmas condições que o grupo Controle (Grupo 2 - LFb6C18h) e ao de CCO mantidos em LFb seguido da maturação por 18h sob as mesmas condições que o grupo 1 (Grupo 3 - LFb6BM18h). A fecundação foi realizada em FERT-TALP por 18h. Os zigotos foram cultivados em SOFaaci, sob óleo mineral, em bolsas plásticas gaseificadas. A taxa de clivagem no Grupo Controle foi superior a do Grupo 3 (P&lt;0,05), mas não houve diferença no percentual de blastocistos no D7 e D9 e no de blastocistos eclodidos entre os 4 grupos. Portanto, oócitos podem ser mantidos por 6h em LFb, a 30ºC, antes da maturação em TCM-HEPES por 18h ou ser maturados por 24h, em TCM-HEPES, em banho-maria a 39ºC, sem atmosfera gasosa controlada. A simplificação da MIV aqui introduzida através do preenchimento de tubos de 1,0mL com TCM-HEPES e manutenção em banho-maria a 39ºC, poderá ser uma opção viável e prática para os programas de OPU/PIV em bovinos

Indução da ovulação com gonadotrofina coriônica humana em éguas Crioulas

The effect of age, follicular diameter and month of the breeding season (September to January) on the hCG induction of ovulation was evaluated using 123 Criollo mares. Age varied between two and 24 years and the animals were examined daily by rectal palpation and ultrasonography with a 5 MHz linear transducer. When ovarian follicles reached a diameter of 30 to 35 mm, ovulation was induced with an i.v. injection of 1000 IU (n = 39); 1500 IU (n = 41) or 2000 IU (n = 43) of hCG. The mares were bred the next day and examined daily until ovulation was detected. The percentage of mares ovulating before 24 h of hCG injection was 10.3%, 7.3% and 4.7%; until 48 h after injection 92.3%, 85.3% and 86.0% of the mares treated with 1000, 1500 and 2000 IU of hCG, respectively, ovulated. The month of the breeding season, age of the mares and follicular diameter had no influence on ovulatory response. The three hCG doses used in Criollo mares (P >; 0.05) result in the induction of ovulation within 48 h after injection when a pre-ovulatory follicle with a 30 to 35 mm diameter was identified. A single dose of 1000 IU of hCG is efficient to induce ovulation in Criollo mares.O efeito da idade, diâmetro folicular e mês da estação de monta (setembro a janeiro) na indução da ovulação com hCG foi avaliado em 123 éguas Crioulas. A idade das éguas variou entre dois e 24 anos e os animais foram examinados diariamente por palpação retal e ultrassonografia com transdutor linear de 5 MHz. Quando os folículos ovarianos atingiram diâmetro de 30 a 35 milímetros aplicou-se uma injeção intravenosa com 1000 UI (n = 39); 1500 UI (n = 41) ou 2000 UI (n = 43) de hCG. As éguas foram cobertas no dia seguinte e examinadas diariamente até a detecção da ovulação. O percentual de éguas que ovularam antes de 24 h da injeção de hCG foi de 10,3%, 7,3% e 4,7%, até 48h após a injeção foi de 92,3%, 85,3% e 86,0%, nos grupos com 1000, 1500 e 2000 UI de hCG, respectivamente. O mês da estação de monta, a idade das éguas ou o diâmetro folicular não influenciaram a resposta ovulatória. As três doses de hCG utilizadas em éguas Crioulas (P &gt;; 0,05) resultaram na indução da ovulação dentro de 48h após a aplicação, quando foi identificado um folículo pré-ovulatório de 30 a 35 mm de diâmetro. Uma única dose de 1000 UI de hCG é eficiente para induzir a ovulação em éguas Crioulas

Abordagem laparoscópica na égua como meio auxiliar nas técnicas de reprodução assistida

Laparoscopy is a poorly explored tool for equine assisted reproduction techniques, despite its use in man, zoo and domestic animals. This study had the objective to evaluate the possibility and offer basis for cannulation of the oviduct and its future application in gamete and embryo transfer programs in this species. Seventeen standing laparoscopies were accomplished in ten mares, each ovary approached from its ipsolateral flank. After identification of the uterine tube, the infundibulum was gently tractioned and a catheter advanced in direction of the abdominal ostium of the uterine tube to the ampulla where 250 µL of culture medium (Dulbecco's - PBS) were deposited. The laparoscopic technique associated with assisted reproduction in the mare can be considered pioneer and have the potential of lowering costs with maintenance of receptors by taking advantage of repetitive cycles, which is impossible by means of the conventional approach through laparotomy. This cost is one of the main obstacles for the commercial application of assisted reproduction techniques in horses.A laparoscopia é uma ferramenta pouco explorada nas técnicas assistidas da reprodução em eqüinos, ao contrário do que já ocorre com o homem, animais de zoológicos e domésticos. Este estudo objetivou verificar a possibilidade de oferecer bases para a canulação do oviduto e sua futura aplicação em programas de transferência de gametas e embriões nesta espécie. Foram realizadas 17 laparoscopias em 10 éguas mantidas em estação onde cada ovário foi abordado pelo flanco ipsolateral. Após identificação da tuba uterina, o infundibulum foi gentilmente tracionado e um cateter avançado em direção ao óstio abdominal da tuba uterina para a ampola, onde foram depositados 250 µl de meio de cultivo (Dulbecco's - PBS). A utilização da técnica laparoscópica em reprodução assistida na égua pode ser considerada pioneira e tem o potencial de diminuir os custos de manutenção de receptoras através do aproveitamento de ciclos repetidos, o que não é possível pela abordagem convencional através de laparotomia. Este custo é um dos principais entraves à aplicação comercial das técnicas assistidas da reprodução em eqüinos

Viability of Pony Stallion Semen in Different Temperature and Dilution

Background: Artificial insemination and transport of cooled semen has been routinely used in equine industry in the past 20 years. However, more investigations are needed regarding the methods for long time storage in pony stallion semen. The effect of dilution and cooling temperature on pH, sperm motility, membrane integrity and mitochondrial activity were investigated before and after cooling of stallion semen.Materials, Methods &amp; Results: Two ejaculates each from nine Brazilian ponies were diluted in a nonbuffered powder milk extender cooled at 5°C or 15°C for 48 h using three different dilutions (1:1, 1:2 or 1:3). Data were assessed by analysis of variance and the rate comparison was performed using the Duncan test. Samples diluted 1:1 at 5oC or 15°C showed higher pH values (7.63 ± 0.34 e 7.57 ± 0.27) and lower progressive motility (10.3 ± 11.05, 17.08 ± 9.95). All samples cooled at 15°C also showed lower incidence of morphologically altered spermatozoa (1:1 = 55.84%; 1:2 = 51.84%; 1:3 = 49.95%) [P &lt; 0.01]. Mitochondrial activity was higher on the 1:3 dilution (0.86 ± 0.19 nm) at 5°C and on the 1:1 (0.89 ± 0.23 nm), 1:2 (0.93 ± 0.2 nm) and 1:3 (0.92 ± 0.2 nm) dilutions at 15°C. Progressive motility was higher when semen was diluted 1:3 and cooled at 15°C (42.22 ± 12.38; P &lt; 0.05). Considering mitochondrial activity, similar results were observed when different dilutions of semen were used (P &gt; 0.05) despite time and temperature. The pH, progressive motility, mitochondrial activity and membrane integrity remained similar (P &gt; 0.05) on fresh semen samples independent of the dilution grade used. The best results were obtained when semen was diluted 1:3 and cooled at 15°C. All dilution grades were safe for fresh semen and pH wasincreased when semen was diluted and cooled for 48 h.Discussion: The methodology used to collect and process equine semen and semen from ponies is practically the same. Equine semen when sent for artificial insemination is usually cooled to 5°C. Our results showed that cooling reduces sperm viability, which has also been demonstrated by other studies. In contrast, the best cooling temperature was at 15°C. However, it is easier to keep the temperature at 5°C during transport, due to the large temperature oscillation that may occur during transportation. The semen of ponies can tolerate cooling at both 5 and 15°C. The 1:3 dilution cooled to 15°C provided better viability of pony sperm, and more stable pH during 48 h of cooling. Dilution 1:1 should not be used for cooling in powdered skim milk extender

Culture of in vitro produced bovine embryos: effect of number of embryos and medium ratio

In the last decade the dairy and beef bovine farms had an increment in their breeding programs that include the use o ovum pick-up and in vitro production (OPU/IVP). Oocytes retrieved by OPU vary in quality and its reduced number requires appropriated culture conditions for IVP. To evaluate the effect of the number of embryos and volume of the media in the in vitro culture of bovine embryos, 1428 zygotes were cultured in groups of 5, 10 or 20 in 1, 5 or 10mL of medium. Groups of 20 oocytes matured in vitro in 200mL of TCM+rFSHh+ 10% estrus cow serum (ECS). The fertilization was performed in groups of 20 oocytes/200mL of Fert-Talp medium, for 18h with 1x10(6) spermatozoa/mL. The culture was done in SOFaaci+5%ECS for 8 days. Considering D0 as the fertilization day, the IVP was evaluated on day 2 (cleavage), day 7 (blastocyst) and in day 9 (hatching rates). The cleavage rates were higher when embryos were cultured in groups of twenty. However, it was not affected by the medium ratio of 1:1, 1:5 and 1:10. The use of 1:5 and 1:10mL of culture medium ratio showed higher embryo production rates in D7 (P&lt;0.05) than 1:1mL proportion. The culture of 20 embryos per drop affected the blastocyst production on day 7. Likewise the hatching rates in D9 were higher with 1:5 and 1:10 than 1:1. Similarly, the hatching rates were higher in cultured of 10 or 20 embryos/drop when compared to groups of 5 embryos/drop. The reduction of embryos and the proportion of the medium volume in culture affects the development indexes on bovine embryos in vitro production.Na última década, os produtores de leite e carne bovina incrementaram consideravelmente o uso da aspiração folicular (OPU) associada à produção in vitro de embriões (IVP). Oócitos recuperados pela OPU têm qualidade diversificada e seu número reduzido requer condições diferenciadas de cultivo para a IVP. Para determinar o efeito do número de embriões e volume de meio sobre a IVP, 1428 embriões bovinos foram cultivados em grupos de 5, 10 e 20, em 1:1, 1:5 e 1:10mL de meio. Grupos de 20 oócitos foram maturados in vitro em 200mL de TCM-199+ rFSHh+10% de soro de vaca em estro (SVE), por 24h. A fecundação in vitro foi em grupos de 20 oócitos/200mL de meio Fert-Talp, por 18h com 1x10(6) espermatozóides/mL. O cultivo foi em SOFaaci+5% SVE por 8 dias. Considerando-se o dia da fecundação como D0, conduziu-se as avaliações no D2 (clivagem), D7 (blastocistos) e no D9 (eclosão). A taxa de clivagem foi superior quando o cultivo foi com 20 embriões e não foi afetada quando a proporção de meio variou (1:1; 1:5 e 1:10). Com as proporções de meio de cultivo 1:5 ou 1:10, a taxa de embriões em D7 foi superior (P&lt;0.05) à 1:1. O número de embriões cultivados influenciou a produção de blastocistos em D7 (P&lt;0,05) com 20 embriões/gota. Estes resultados também se refletem nos percentuais de blastocistos eclodidos em D9, sendo que 1:5 e 1:10 foram superiores (P&lt;0,05) à 1:1. Da mesma forma, a taxa de eclosão foi superior (P&lt;0,05) com o cultivo de 10 ou 20 embriões/gota quando comparado ao grupo de 5 embriões/gota. A redução do número de embriões e da proporção de volume de meio no cultivo, afeta os índices de desenvolvimento na produção in vitro de embriões bovinos

Taxa de gestação em éguas da raça crioula após aspiração folicular guiada por ultrassom

Há poucos estudos sobre aspiração folicular transvaginal guiada por ultrassom na medicina equina abordando complicações futuras na fertilidade das éguas aspiradas. Com o objetivo de avaliar o efeito da aspiração folicular na fertilidade das éguas, foram conduzidos dois experimentos. No experimento I, 15 éguas da raça Crioula foram distribuídas em três grupos de acordo com o diâmetro do folículo aspirado durante o estro: 25-29mm (n=4; grupo 1); 30-34mm (n=6; grupo 2); > 35mm (n=5; grupo 3) e grupo controle (n=15; grupo 4). No experimento II, a aspiração folicular foi realizada em 25 éguas durante o diestro quando pelo menos 4 folículos (>5mm) foram observados na ultrassonografia transretal em ambos os ovários. Foram aspirados todos os folículos visíveis, entre 4 e 8 mm. Trinta e uma éguas serviram como controle. No experimento I, a taxa de prenhez no ciclo seguinte a aspiração foi de 75% (grupo 1), 83,3% (grupo 2), 60% (grupo 3), e 73,3% (grupo 4). No experimento II foi de 76% no grupo aspirado e 77,4% no grupo controle (não aspirado). Em ambos os experimentos, as taxas de prenhez foram similares (P>0,05). Os resultados mostram que a taxa de concepção no primeiro ciclo após a aspiração folicular não é afetada pelo procedimento.There are few studies about transvaginal ultrasound-guided follicle aspiration in equine medicine regarding potential complications to future fertility of aspirated mares. In order to evaluate the effect of follicular aspiration on subsequent fertility in mares, two experiments were conducted. In Experiment I, fifteen Criollo mares were allocated to one of three groups according to the diameter of the aspirated follicle during estrus: 25-29mm (n=4; Group 1); 30-34mm (n=6; Group 2); > 35mm (n=5; Group 3) and control group (n=15; Group 4). In Experiment II, the follicular aspiration was attempted in twenty-five mares during diestrous, when at least four follicles (> 5mm) were seen in the transrectal ultrasonography of both ovaries. All visible follicles, between 4 and 8 mm, were aspirated. Thirty-one mares served as control. In Experiments I and II, the pregnancy rates in the following cycle after aspiration were 75.0% (Group 1), 83.3% (Group 2), 60.0% (Group 3), and 73.3% (Group 4 - Control); and 76.0% in the aspirated diestrous group and 77.4% in the control group (non aspirated), respectively. On both experiments, pregnancy rates were similar (P>0.05) in treated and control mares. The results of this study show that the conception rates of the first estrus period following follicular aspiration are not affected by the procedure

PREGNANCY RATES IN CRIOLLO BREED MARES AFTER ULTRASOUND-GUIDED FOLLICULAR ASPIRATION

There are few studies about transvaginal ultrasound-guided follicle aspiration in equine medicine regarding potential complications to future fertility of aspirated mares. In order to evaluate the effect of follicular aspiration on subsequent fertility in mares, two experiments were conducted. In Experiment I, fifteen Criollo mares were allocated to one of three groups according to the diameter of the aspirated follicle during estrus: 25-29mm (n=4; Group 1); 30-34mm (n=6; Group 2); > 35mm (n=5; Group 3) and control group (n=15; Group 4). In Experiment II, the follicular aspiration was attempted in twenty-five mares during diestrous, when at least four follicles (> 5mm) were seen in the transrectal ultrasonography of both ovaries. All visible follicles, between 4 and 8 mm, were aspirated. Thirty-one mares served as control. In Experiments I and II, the pregnancy rates in the following cycle after aspiration were 75.0% (Group 1), 83.3% (Group 2), 60.0% (Group 3), and 73.3% (Group 4 - Control); and 76.0% in the aspirated diestrous group and 77.4% in the control group (non aspirated), respectively. On both experiments, pregnancy rates were similar (P>0.05) in treated and control mares. The results of this study show that the conception rates of the first estrus period following follicular aspiration are not affected by the procedure. KEYWORDS: equine, fertility, follicular aspiration, mares.

Individual culture of in vitro produced bovine blastocysts

In vitro produced bovine embryos were individually cultured from D7 to D9 to observe their development. Forty-nine blastocysts (early blastocyst, blastocyst and expanded blastocyst) were individually cultured, from D7 to D9 (D0= fertilization), in 50ml SOF medium plus 5% OCS. Between D7 and D8, blastocysts were cultured in straws (SC) or in plates (PC) and from D8 up to D9, they were cultured on plates. The ratio of early blastocyst, blastocyst, and expanded blastocyst advancing at least one stage of development were, respectively, 71%, 37%, 44% in PC and 100%, 66%, 36% in SC (P&gt;;0.05). Overall development rates on D8 were not significantly different (P&gt;;0.05) for PC (50%) and SC (60%). At D9, both culture systems produced similar (P&gt;;0.05) hatching rates (29% and 24% for PC and SC, respectively). After fluorescent nuclei staining, the average number of cells counted in the hatched (182.7 vs. 202.8) and expanding (94.5 vs. 88.0) blastocysts were similar (P&gt;;0.05) for PC and SC, respectively. In vitro produced bovine blastocysts can be individually cultured from D7 to D9, and the culture system employed (dishes or straws) has no effect on hatching rates and cell number of developed blastocysts.Embriões bovinos produzidos in vitro foram cultivados individualmente do D7 ao D9, com o intuito de avaliar o seu desenvolvimento posterior. Quarenta e nove embriões, nos estágios de blastocisto inicial, blastocisto e blastocisto expandido foram cultivados, individualmente, em 50ml de meio SOF + 5% SVE, do D7 ao D9 (D0=fecundação). Entre o D7 e D8, os blastocistos foram cultivados em palhetas (TcP) ou em placas (CP) e, entre o D8 e D9, foram cultivados apenas em placas. O índice de blastocistos que avançaram pelo menos um estágio de desenvolvimento, entre D7 e D8, foi de 71%, 37% e 44% no CP e de 100%, 66% e 36% no TcP, respectivamente para blastocistos iniciais, blastocistos e blastocistos expandidos. O percentual total de embriões que evoluíram do D7 para D8 foi de 50% (12/24) para o CP e de 60% (15/25) para o TcP, os quais não foram significativamente diferentes (P&gt;;0,05). Na avaliação efetuada no D9, não foram constatadas diferenças (P&gt;;0,05) no percentual de blastocistos eclodidos, entre os dois sistemas de cultivo (29% e 24% para CP e TcP, respectivamente). Após coloração fluorescente dos núcleos, não foi observada diferença (P&gt;;0,05) entre o número médio de células dos blastocistos eclodidos (182,66 vs. 202,8) e expandidos (94,5 vs. 88), para o CP e TcP, respectivamente. Blastocistos bovinos produzidos in vitro podem ser cultivados individualmente do D7 ao D9, não havendo efeito do sistema de cultivo empregado (placas ou palhetas) sobre a taxa de eclosão e o número de células