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This retrospective study aimed at identifying factors that contribute to the success of equine in vitro embryo production by intracytoplasmic sperm injection (ICSI). A total of 7993 ovum pick-up (OPU) sessions were performed, totaling 2540 donor mares and semen from 396 stallions. Oocytes were aspirated at multiple sites in Brazil and were sent to the laboratory, within 6 h from OPU, in pre-maturation medium where they were in vitro matured (IVM) followed by ICSI and in vitro embryo culture for 7-8 days. The number of recovered oocytes, matured oocytes, cleaved embryos and blastocysts were used to explore the effect of age and breed of the donor mare, time of year in which the mare was aspirated and phase of the estrous cycle on the day of follicular aspiration. Mares between 6 and 15 years old were superior to other age groups in most parameters evaluated, including the average number of blastocysts per OPU. The impact of age was similar when evaluated within two breeds, American Quarter Horse (AQHA) and Warmblood mares. We observed that breed (AQHA, Warmblood, Crioulo, Lusitano and Mangalarga) had an important effect on most of the parameter evaluated, including number of oocytes recovered, blastocysts produced per OPU, and blastocyst rates. The overall impact of season was less pronounced than age and breed, with the only statistically significant difference being a higher rate of oocyte maturation during the summer season. Finally, most of the parameters evaluated were superior in follicular phase mares, with or without dominant follicle than luteal phase mares. In conclusion, this retrospective study revealed that breed, age, season and stage of estrous at the time of OPU are all important parameters for the success of equine embryo production by ICSI. This technology enables producing embryos all-year-round from mares of different breeds and ages from OPU-derived oocytes collected at multiple sites.

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The objective of this study was to evaluate the effect of three doses of equine chorionic gonadotropin (eCG) for ovarian superstimulation on ovarian response, follicular development and cumulus-oocyte complexes (COCs) collection in llamas. For this purpose, eighteen multiparous non-lactating adult (4-7 yo) female llamas with an average body condition of 2.8 (BCS 1-5) were submitted to a follicular ablation (FA) to induce a new follicular wave emergence. Two days after FA (Day 0), synchronized llamas were randomly allocated to three treatment groups (n = 6/group) and given 500, 750 and 1000 IU of eCG (Novormon®, Syntex, Buenos Aires, Argentina) per animal respectively to induce ovarian superstimulation. Transrectal ultrasonography were performed on Days 2, 4, and 6; and ovum pick up (OPU) was performed on Day 6. Data was evaluated by one-way analysis of variance (ANOVA), repeated measures ANOVA, and 2-tailed Chi-square. The average size (mm) of follicles was greater (p≤ 0.05) in the 1000 IU group compared to the other groups. There was a greater (p≤ 0.05) number of follicles ≥ 7 mm in the 1000 IU group compared to the 500 IU group. Number of COCs collected on Day 6 and the COC recovery rate were not different among groups. In conclusion, a single dose of 1000 IU of eCG induced the best ovarian response resulting in larger and greater number of follicles at the time of OPU.

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The potential of chicken eggs as a nutritionally complete protein and source of key micronutrients during the first 1000 days post-conception has been progressively recognized across the globe, particularly in resource-poor settings. Fluctuation of egg nutrient content by season is relatively unknown, which may influence international food composition databases and outcomes in intervention studies using egg supplementation. To better interpret the findings of The Saqmolo' Project, we conducted comprehensive nutrient analyses on eggs produced during the wet and dry seasons in the highlands of central Guatemala. We randomly collected 36 shell eggs from a local farm during both seasons, hard-boiled, and prepared them for transport to the United States, where they were pooled and assessed for their nutrient composition. Methods of the Association of Official Analytical Chemists, the American Oil Chemists Society, and the American Association of Cereal Chemists were utilized to determine total energy, moisture, ash, total protein, total fat, fatty acids, total carbohydrates, 12 vitamins, 11 minerals, and carotenoids, by season, in some instances with modifications. Differences in nutrient composition between de-shelled hard-boiled eggs collected between seasons were assessed using an analysis of variance (ANOVA) and Tukey's family error rate comparison test. Most nutrients in eggs produced in the highlands of central Guatemala differed negligibly (but statistically significantly) based on seasonality. Only vitamins A and E, folate, choline, and calcium fluctuated at clinically significant levels relative to the AI/RDA for infants 7-12 months. Total energy, protein, trans fatty acids, moisture, and vitamin D3 levels did not differ between seasons (p > .05). Further multi-year sampling is needed to examine how seasonal variation affects the nutrient composition of eggs. These data may be used to supplement existing national and regional food composition databases.

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The aim of this study was to compare embryo production efficiency in Flemish and Holstein donor females using ovum pick-up and in vitro fertilization (OPU-IVF) or in vivo production (superovulation; SOV) procedures. The study was conducted using a split-plot design, with eight Flemish and eight Holstein non-lactating cycling females. Females were subjected to ten weekly OPU/IVF sessions and/or two SOV/embryo collections sessions at a 63-day interval, for a total of 160 OPU-IVF and 32 SOV sessions. Mean numbers of follicles and corpora lutea, and cumulus-oocyte complex (COC) recovery rates were similar between breeds after the OPU and SOV sessions. However, Flemish donors yielded better quality grade II COCs (301, 41.9%) than Holstein females (609, and 202, 33.1%). Also, cleavage and blastocyst rates, and the total number and the mean number of viable embryos obtained after OPU-IVF were higher in Flemish (49.6% and 11.8%, and 63 and 11.8 per donor, respectively) than in Holstein (32.8% and 7.2%, and 34 and 7.2 per donor, respectively) females. Flemish females were also more efficient in yielding viable embryos after SOV (111, 7.3 per donor) than Holstein (48, 3.3 per donor) females. Overall, Flemish donor females had better responses to OPU-IVF or SOV procedures than Holstein counterparts. Irrespective of the breeds, SOV procedures were more efficient than OPU-IVF in yielding more viable embryos, under the conditions of this study. Both reproductive procedures were useful tools for the genetic conservation of the Flemish cattle breed in Southern Brazil.

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The following report describes the case of an ectopic pregnancy with contralateral corpus luteum after spontaneous conception. The patient was a 33- year-old female (gravida 3, segmentary C sections 3), with positive pregnancy test, and an Intrauterine Device (IUD). The patient was asymptomatic. At vaginal ultrasound, we observed an anteverted uterus of normal shape and size, a 20 x 12 mm intramural myoma and an irregular endometrial thickness of 16.5 mm, with no intrauterine sac. An ectopic pregnancy in the left Fallopian tube and a contralateral corpus luteum were detected, possibly as consequence of ovum pick up through the opposite tube (oocyte transmigration). Further laparoscopic and histopathologic studies confirmed our findings, and the ectopic pregnancy was successfully removed. In conclusion, oocyte transmigration is a common event and should be account when we wish to provide medical advice to patients with a single Fallopian tube trying to conceive. There are real chances for a patient to become pregnant even when only a single tube is present.

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As biotécnicas de produção in vivo e in vitro de embriões bovinos permitem aumentar significativamente o número de descendentes de fêmeas genética e/ou zootecnicamente importantes. Porém, antes de se optar por um dos métodos, deve-se avaliar suas peculiaridades. A produção in vivo pode ser empregada de forma satisfatória tanto em zebuínos quanto em raças sintéticas e taurinas, permitindo a obtenção de, em média, seis a sete embriões viáveis por coleta, com boa tolerância à criopreservação. Já a produção in vitro é mais eficiente em raças zebuínas e sintéticas, visto que possuem maior número de folículos antrais aspiráveis. Além disso, esta técnica permite a produção de embriões sem estímulos hormonais exógenos, porém com menor criotolerância. Desse modo, a presente revisão discute os desafios atuais e perspectivas futuras na produção de embriões in vivo e in vitro com base nos dados da rotina de uma central de doadoras e laboratório de produção de embriões que desenvolve simultaneamente ambas as técnicas de produção de embriões na região Sul do Brasil.(AU)

Biotechniques for in vivo and in vitro production of bovine embryos allow to significantly increase the number of descendants from cows genetically and/or zootechnically superior. However, before opting for one of the methods, one should evaluate its peculiarities. In vivo production can be used satisfactorily both in zebu cattle and in synthetic and taurine breeds, allowing to obtain, on average, six to seven viable embryos per procedure, with good tolerance to cryopreservation. In vitro production is more efficient in Zebu and synthetic breeds, since they have a greater number of aspirable antral follicles. In addition, this technique allows the production of embryos without exogenous hormonal stimuli, but with lower cryotolerance. This review discusses current challenges and future perspectives in in vivo and in vitro embryo production based on routine data from an embryo production center and a laboratory that develop, simultaneously, the two embryo production techniques in southern Brazil.(AU)

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The morphological quality and the in vitro developmental competence of cumulus-oocyte complexes (COCs) collected from in vivo or slaughtered alpacas was compared. COCs were recovered from ovarian follicles using: (i) manual aspiration in ovaries of alpacas (n = 15) sacrificed at a local slaughterhouse, or (ii) transrectal ultrasound-guided follicular aspiration (or ovum-pick-up, OPU) in live alpacas (n = 13) 4 days after the administration of an ovarian superstimulation protocol (200 UI eCG). COCs recovered from both groups were morphologically evaluated and graded. Grade I to III COCs were in vitro matured for 26 h and in vitro fertilized afterwards for 20 h using fresh alpaca epididymal spermatozoa. Presumptive zygotes from both groups were in vitro cultured for 7 days. The proportion of COCs recovered over the total number of follicles punctured was similar between groups, but the mean number of COCs collected from individual ovaries was greater (p < 0.05) in slaughterhouse ovaries. A significantly higher (p < 0.05) percentage of low-quality COCs (grades III and IV) and a lower (p < 0.05) percentage of grade I COCs was obtained using OPU. The number of blastocysts, regarding cleavage and COCs collected, was higher (p < 0.007 and p < 0.0002 respectively) for COCs collected by OPU; however, the total number of blastocysts per female did not differ between groups. We can conclude that the recovery rate and morphological quality of COCs was significantly higher when follicles were manually aspirated from slaughterhouse alpaca ovaries; however, a statistically higher developmental potential was observed in oocytes collected by OPU from live alpaca donors.

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OBJECTIVE: Recurrent implantation failure is defined as failure to achieve clinical pregnancy after the transfer of four or more good-quality embryos in a minimum of three fresh or frozen cycles in a woman aged less than 40 years. The objective is to compare between the effect of intrauterine G-CSF, hCG, and saline solution injection (as placebo) at the day of ovum pick-up on clinical pregnancy, chemical pregnancy, implantation, and miscarriage rates in patients with recurrent implantation failure undergoing IVF/ICSI. METHODS: This prospective, double blind, parallel, randomized controlled trial included 150 patients equally divided into 3 groups, each containing 50 individuals. Subjects in Group 1 received intrauterine injections of G-CSF; Group 2: received intrauterine injections of 500 IU of hCG; and Group 3 received intrauterine injections of saline solution as placebo. The primary outcome measure is clinical pregnancy rate. Secondary outcomes are biochemical pregnancy, implantation, and miscarriage rates. RESULTS: Clinical pregnancy, biochemical pregnancy, and implantation rates were highest in the group given G-CSF and lowest in the group administered saline solution; miscarriage rates were not significantly different between the groups. CONCLUSIONS: Intrauterine administration of G-CSF at a dose of 100 µg/1.0 cc at the time of ovum pick-up is associated with better clinical pregnancy, chemical pregnancy, and implantation rates as compared with intrauterine saline solution administration. Further studies are needed to determine the optimum timing of intrauterine administration of G-CSF that achieves the best results, and longer follow-up is needed to determine take-home baby percentages.

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The objective of this study was to evaluate the influence of thermal shock on oocytes used in the production of in vitro embryos (IVP) of high productivity Holstein cows on the day of follicular aspiration (OPU; 0), 30, 60 and 90 days before the OPU. From the mean temperature on day 0 and on the previous 30, 60 and 90 days, they were classifed into comfort group (TC; up to 15°C) and heat stress (HS; above 15°C) groups.Anegative influence was observed on oocytes and viable embryos (total and grade I). The heat stress in the periods of 30 and 60 days prior to OPU resulted in lower production of viable oocytes (P=0.0028; P=0.0092, respectively). Under stress, on the day of OPU (HS-OPU), cows showed no reduction in the amount of viable oocytes (P=0.5497) and there was no influence of temperature for the group stressed 90 days before OPU (P=0.8287). For total embryos, the difference occurred only in the HS-30 group (P=0.0317), where the groups HS-OPU, HS-60, HS-90 presented, respectively, P=0. 1987, P=0.0596 and P=0.4580. Regarding the production of embryos of grade 1, there was no difference for the groups HS-OPU (P=0.2291) and HS-90 (P=0.2868), but there was a reduction for HS-30 (P=0.0143) and HS-60 (P=0.0253). In summary, heat stress had a negative impact when it occurred 30 or 60 days before follicular aspiration. In addition, 30 days seems to be the period of more susceptibility and that causes the greatest deleterious effects on oocyte viability and IVP.(AU)

Objetivou-se avaliar a infuência do estresse térmico em oócitos utilizados na produção in vitro de embriões (PIV) bovinos da raça Holandesa de alta produtividade no dia da aspiração folicular (OPU; 0), 30, 60 e 90 dias antes da OPU. A partir da temperatura média no dia 0 e aos 30, 60 e 90 dias anteriores, foram classificados nos grupos conforto (CT; até 15°C) e estresse por calor (ET -acima de 15°C). Observou-se infuência negativa em oócitos e embriões viáveis (total e grau I). A submissão ao estresse térmico nos períodos de 30 e 60 dias anteriores à OPU resultou em menor produção de oócitos viáveis (P=0,0028; P=0,0092, respectivamente). Sob estresse, no dia da OPU (ET-OPU), as vacas não apresentaram redução na quantidade de oócitos viáveis (P=0,5497) e não houve infuência da temperatura para o grupo estressado 90 dias antes da OPU (P=0,8287). Para embriões totais, a diferença ocorreu apenas no grupo ET-30 (P=0,0317), onde os grupos ET-OPU, ET-60, ET-90 apresentaram, respectivamente, P=0,1987, P=0,0596 e P=0,4580. Em relação à produção de embriões grau 1, não houve diferença para os grupos ET-OPU (P=0,2291) e ET-90 (P=0,2868), porém houve redução para ET-30 (P=0,0143) e ET- 60 (P=0,0253). Em resumo, o estresse por calor teve impacto negativo quando ocorreu 30 ou 60 dias antes da aspiração folicular. Além disso, 30 dias parece ser o período de maior suscetibilidade e que causa os maiores efeitos deletérios na viabilidade oocitária e na PIV.(AU)

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Background: This study aimed to determine the effects of environmental temperature on the number and quality of oocytes and embryo production rates obtained by performing ovum pick up (OPU). Heat stress leads to long-term, short-term, visible, and invisible effects in dairy cows. Its effects on reproduction are evident in all stages, from oocyte development to birth. Disturbance in ovarian follicle development, follicular dominance deficiency, anoestrus, polyspermia, embryonic losses, decreased fetal growth, and abortion are some examples of responses to these effects. The aim of the present study was aimed to determine the effects of ambient temperature on oocyte quality and number and embryo production rates. Materials, Methods & Results: The animal material used in this study comprised 10 Holstein heifers. At the beginning of the study, the heifers were 13-15 months old. OPU was performed at different times of the year, and weather conditions were recorded. Grouping according to ambient temperature was done as < 10°C (group 1), 10-25°C (group 2), and > 25°C (group 3). The veterinary ultrasonography device and a set of compatible intravaginal OPU probe, catheter, and aspiration device were used for OPU application. All antral follicles with diameters of 2-8 mm in the ovaries were aspirated. The aspirated follicle fluids were examined under a stereo microscope, and the cumulus-oocyte complexes (COC) were collected and classified according to their structure. A, B, and C-quality oocytes were included in the in vitro embryo production process. After performing 69 OPUs on random days of the cycle, the number of oocytes per OPU was found to be 8.72, 6.32, and 6.85 in groups 1, 2, and 3, respectively (P < 0.05). The number of viable oocytes per OPU was 6.83, 4.64, and 4.65 in groups 1, 2, and 3, respectively (P < 0.05). The statistical difference between the first group and the other groups was significant for cleavage and blastocyst counts (P < 0.05). Discussion: All the negative effects of heat stress on animals resulted from the increased body temperature. Reproductive performance is adversely affected by high temperatures and humidity during periods of high ambient temperatures. Metabolic heat is released, and the heat load increases due to the metabolism of nutrients in cattle. Internal body temperature is regulated via the dissipation of metabolic heat to the environment. The amount of heat dissipated via conduction and convection depends on the unit body weight, surface area, skin and coat color, difference in temperature gradient of the animal and ambient temperature, and humidity. In the present study, it was determined that the blastocyst development rates of the oocytes obtained in the warm season (>25°C [group 3]) were lower than those of the other groups. It was concluded that this may be because the oocytes developed under chronic heat stress in the animals, and several cycles were required to enhance oocyte quality and developmental potential. Additional studies are needed to investigate the response of oocytes obtained with OPU to heat stress during embryonic developmental stages and to determine the sensitivity and effects of embryonic tissue damage according to developmental stages. Based on the results of the present study, it was concluded that performing OPU and in vitro embryo production (IVEP) when the ambient temperature is close to the thermoneutral limits may increase the blastocyst development rates.

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The objective of this work is to estimate genetic parameters and breeding values to improve embryo and oocyte production, using repeatability and random regression models (RRM) for Gir dairy cattle. We used 11,398 records of ovum pick-up from 1,747 dairy Gir donors and evaluated sixteen different models: the traditional repeatability model and fifteen RRM, each of which considered a different combination of Legendre polynomial regressors to describe the additive genetic and permanent environment effects. The 4G1P model (four regressors for the genetic effect and one regressor for the permanent environment effect) is the most suitable model to analyze the number of viable and total oocytes, while the 3G1P is the best model to analyze the number of cleaved and viable embryos, according to the values of the Akaike information criterion (AIC) and the Bayesian information criterion (BIC). The heritability estimated with the RRM was higher than that estimated with the repeatability model. The high repeatability reported for oocyte and embryo count traits indicates that donors, which had high oocyte and embryo counts in the first ovum pick-up, should maintain this result in the next ovum pick-up. Genetic correlations between adjacent ages were high and positive, while genetic correlations between extreme ages were weak. We observed a reranking of the top sires and females (heifers and cows) over the period evaluated. The reliability of the estimated breeding values by RRM showed changes across age, and the expected genetic gains by RRM are larger. This shows that RRM is most suitable alternative for the evaluation and selection of oocyte and embryo count traits.(AU)

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BACKGROUND: Stress has been considered as one of the causes of decreased reproductive function in women. However, direct evidence of the effect of chronic stress on oocytes depending on estrous cycle phases is limited. OBJECTIVE: The present study aimed to evaluate the impact of chronic stress on the viability, integrity, and maturation of rat oocytes depending on estrous cycle phases, specifically proestrus, estrus, and diestrus. METHODS: For this purpose, adult female rats were stressed daily by cold water immersion (15 °C) for 30 consecutive days. RESULTS: In chronically stressed female rats, irregular estrous cyclicity, increased corticosterone levels, decreased oocyte viability, and an increased percentage of abnormal oocytes were obtained in all the estrous cycle phases, resulting in reduced oocyte maturation during proestrus. CONCLUSION: Oocyte maturation disturbed by chronic stress is a crucial factor by which chronic stress disrupts female reproduction.

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We aimed to evaluate the morphological ovarian response to equine chorionic gonadotropin (eCG) prior to ovum pick-up (OPU) and its effects on the molecular phenotype of immature cumulus-oocyte complexes (COCs) from Nelore cow (Bos indicus) donors. To this end, 20 Nelore cows were distributed randomly into the synchronized-OPU (Sync-OPU) and synchronized plus stimulated-OPU (Sync + eCG-OPU) groups using a cross-over experimental design, as each cow was used in both treatments. On a random day of the estrus cycle (Day 0), all cows received an intravaginal implant with 1.0 g of progesterone and 2 mg IM of estradiol benzoate. On the morning of Day 3, only the Sync + eCG-OPU group received 400 IU of eCG IM. On the morning of Day 5, the P4 device was removed and OPU was conducted in both groups. Before OPU management, ultrasonography was used to identify and measure the follicles. The aspirated COCs were morphologically classified based on their cumulus cells (CC) layers and the texture of the ooplasm. The COCs classified as Grade 1, Grade 2, and Grade 3 were considered viable and used for the assessment of quality markers. Oocytes and CC were mechanically separated from pools of 25 immature COCs of the Sync-OPU and Sync + eCG-OPU groups immediately after the follicular aspiration and stored at -80 °C until RNA extraction. Relative quantification of several markers for oocyte quality was assessed by RT-qPCR. The eCG treatment increased the number of follicles sized 3.0-5.0 mm and >5.0 mm compared to that in Sync-OPU group. Moreover, the protocol with eCG improved the total number of oocytes and the number of viable oocytes, which is related to a high number of oocytes in Grade 3. Regarding the impact on transcriptional regulation in immature oocytes, the mRNA encoding BMP15, SMAD1, SMAD2, SMAD3, ACACA, and CPT1A was upregulated in Sync + eCG-OPU compared with the Sync-OPU group. Moreover, the relative mRNA abundance of CTSZ, a member of the cathepsins family functionally related to reduced oocyte competence, was lower in the Sync + eCG-OPU group than in the Sync-OPU group. In addition, CC CTSB, CTSS, and CTSK mRNA abundances were lower in the Sync + eCG-OPU group than in the Sync-OPU group. However, the relative abundance of AREG and EREG mRNA was higher in CC recovered from cows stimulated with eCG. In conclusion, the eCG approach addressing follicular stimulation in Nelore cows had a positive impact on early antral follicle development, followed by a positive morphological and molecular phenotype in bovine COCs.

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In vitro production of embryos has gained prominence as a tool for use in wildlife conservation programmes in situ and ex situ. However, the development of this technique depends on steps that include ovarian stimulation, collection and oocyte maturation. The purpose of this study was to assess the feasibility of an ovarian stimulation protocol for follicular aspiration, the efficiency of videolaparoscopy for follicular aspiration and test a medium for in vitro oocyte maturation for the species Mazama gouazoubira. Five females were submitted to repeated ovarian stimulation (hormone protocol using controlled internal drug release), and estradiol benzoate on D0 and eight injections of follicle-stimulating hormone, once every 12 h, from D4 onwards at 30-day intervals. Fourteen surgical procedures were performed in superstimulated females, resulting in the collection of 94 oocytes and an average of 17.1 ± 9.1 follicles observed, 13.5 ± 6.6 follicles aspirated and 7.2 ± 3.7 oocytes collected per surgery. After collection, the oocytes were submitted to in vitro maturation for 24 h and stained with Hoechst 33342 dye to evaluate their nuclear status; 64.5% of the oocytes reached MII and 16.1% were spontaneously activated by parthenogenesis. The nuclear status of oocytes that did not undergo in vitro maturation was evaluated; 80.9% were found to be immature.

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This study was performed to evaluate the effects of supplementation of lactating Nelore cows with calcium salts of long-chain fatty acids (Ca-LCFA) of soybean oil on in vitro oocytes competency, cleavage rate, embryo production rate, pregnancy rate, and sex ratio of transferred embryos. Fifteen multiparous Nelore cows grazed on a Tifton 85 pasture were allotted to two treatments: (1) supplement without fat inclusion (CONT, n = 6) and (2) supplement containing 47.2 g Ca-LCFA /kg (to provide an intake of 0.2 kg Ca-LCFA/day) based on dry matter (n = 9). Animals were subjected to 2.53 ± 1.35 rounds of consecutive ovum pick up at intervals of 27.65 ± 21.72 days. Oocytes were morphologically evaluated, selected, maturated, fertilized, and cultivated for embryo production in vitro and then transferred into recipients who had previously undergone an embryo transfer protocol at a fixed time. The number of aspirated oocytes, the proportion of viable oocytes, cleavage rate, embryo percentage, pregnancy rate, and sex ratio were not affected when Nelore cows were supplemented with Ca-LCFA of soybean oil compared with non-supplemented Nelore cows. In conclusion, our results suggest that feeding a supplement containing 47.2 g Ca-LCFA/kg (to provide an intake of 0.2 kg Ca-LCFA/day) to Nelore cows does not affect in vitro embryo production in lactating Nelore cows. However, further studies...(AU)

Este estudo foi realizado para avaliar os efeitos da suplementação de vacas Nelores em lactação com sais de cálcio de ácidos graxos de cadeia longa (Ca-SCACL) feitos com óleo de soja sobre a competência in vitro de oócitos, taxa de clivagem, taxa de produção de embriões, taxa de prenhez e proporção de sexo de embriões transferidos. Foram utilizadas 15 vacas Nelore (lactantes, multíparas e mantidas em pastagem de Tifton 85) distribuídas em dois tratamentos: (1) suplemento sem inclusão de lipídios (CONT, n = 6) e (2) suplemento contendo 47,2 g Ca-SCACL/kg (para proporcionar uma ingestão de 0,2 kg Ca-SCACL/ dia) com base na matéria seca (n = 9). Os animais foram submetidos a 2,53 ± 1,35 rodadas consecutivas de aspiração folicular a intervalos de 27,65 ± 21,72 dias. Os oócitos foram avaliados morfologicamente, selecionados, maturados, fertilizados e cultivados para produção de embriões in vitro. Em seguida, os embriões foram transferidos para receptoras previamente submetidas a um protocolo de transferência de embriões em tempo fixo. O número de oócitos aspirados, a proporção de oócitos viáveis, a taxa de clivagem, a porcentagem de embriões, a taxa de prenhez e a proporção de sexo de embriões não foram afetados quando as vacas Nelore foram suplementadas com Ca-SCACL de óleo de soja em comparação com as vacas Nelore não suplementadas. Em conclusão, nossos resultados sugerem que suplemento contendo 47,2 g de Ca-SCACL/kg (para fornecer uma ingestão de 0,2 kg de Ca-SCACL) não afeta a produção in vitro de embriões de vacas Nelore em lactação. No entanto, novos estudos utilizando doses mais altas de gordura na dieta poderiam ser úteis para determinar o seu potencial sobre produção embrionária in vitro.(AU)

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In the present study, there was an evaluation of in vitro embryo production (IVEP) in Bos indicus donor cows with small or large antral follicle counts (AFCs) when there was synchronization of follicular dynamics among cows before ovum pick-up (OPU). Donor cows classified as having small or large AFC were submitted to OPU/IVEP program (Experiment-I) or had follicular-stage synchronization imposed before OPU/IVEP (Experiment-II). In Experiment-I, the cows with a large AFC had a greater (P < 0.01) mean of embryos developing to the blastocyst stage compared to those with a small AFC. In Experiment-II, percentage of viable oocytes/OPU were not affected (P = 0.33) by synchronization of follicular dynamics, but the AFC had an effect (P < 0.0001). There was an interaction (P = 0.01) indicating the larger AFC, with or without imposing of a synchronization treatment regimen, resulted in the most desirable outcome. The number of embryos was affected (P < 0.001) by follicular-stage synchronization and AFC, with there being an interaction (P = 0.002) with the most desirable results for the large AFC-synchronized group. Number of pregnancies was greater (P ≤ 0.02) for recipient females with embryos from synchronized donors and with a large AFC. There was an interaction (P = 0.03) with there being a greater pregnancy percentage for cows with synchronized follicular stages and the large AFC. Bos indicus donor with a large AFC when associated with the synchronization of stage of follicular dynamics pre-OPU results in improvement of the efficacy of IVEP.

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The objective of the present study was to evaluate efficiency of in vitro fertilization (IVF) in Nelore, Brangus, and Girolando oocyte donors. Ovum pickup (OPU) from the donors was conducted every 15 days to assess oocyte recovery, IVF, and post-transfer pregnancy percentage. For Nelore, the mean numbers of total and viable oocytes recovered (23.5 ± 1.1 and 14.0 ± 1.0, respectively) were higher (p < 0.05) than those for Brangus (12.7 ± 1.9 and 6.6 ± 1.0, respectively) and Girolando (12.5 ± 1.4 and 6.8 ± 0.7, respectively); Brangus and Girolando did not differ from each other (p > 0.05). The percentage of blastocyst production differed (p < 0.05) between Nelore (48.4 ± 2.4%), Brangus (40.3 ± 3.6%), and Girolando (38.9 ± 2.6%), but those in Brangus and Girolando did not differ (p > 0.05). The percentage of blastocysts (transferred) that resulted in pregnancy did not differ (p > 0.05) between Nelore (45.5 ± 3.8%), Brangus (41.7 ± 4.1%), and Girolando (40.7 ± 3.7%). Of the breeds studied, Nelore donors are more efficient for IVF, but conditions of this study.

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This study was performed to evaluate the effects of supplementation of lactating Nelore cows with calcium salts of long-chain fatty acids (Ca-LCFA) of soybean oil on in vitro oocytes competency, cleavage rate, embryo production rate, pregnancy rate, and sex ratio of transferred embryos. Fifteen multiparous Nelore cows grazed on a Tifton 85 pasture were allotted to two treatments: (1) supplement without fat inclusion (CONT, n = 6) and (2) supplement containing 47.2 g Ca-LCFA /kg (to provide an intake of 0.2 kg Ca-LCFA/day) based on dry matter (n = 9). Animals were subjected to 2.53 ± 1.35 rounds of consecutive ovum pick up at intervals of 27.65 ± 21.72 days. Oocytes were morphologically evaluated, selected, maturated, fertilized, and cultivated for embryo production in vitro and then transferred into recipients who had previously undergone an embryo transfer protocol at a fixed time. The number of aspirated oocytes, the proportion of viable oocytes, cleavage rate, embryo percentage, pregnancy rate, and sex ratio were not affected when Nelore cows were supplemented with Ca-LCFA of soybean oil compared with non-supplemented Nelore cows. In conclusion, our results suggest that feeding a supplement containing 47.2 g Ca-LCFA/kg (to provide an intake of 0.2 kg Ca-LCFA/day) to Nelore cows does not affect in vitro embryo production in lactating Nelore cows. However, further studies...

Este estudo foi realizado para avaliar os efeitos da suplementação de vacas Nelores em lactação com sais de cálcio de ácidos graxos de cadeia longa (Ca-SCACL) feitos com óleo de soja sobre a competência in vitro de oócitos, taxa de clivagem, taxa de produção de embriões, taxa de prenhez e proporção de sexo de embriões transferidos. Foram utilizadas 15 vacas Nelore (lactantes, multíparas e mantidas em pastagem de Tifton 85) distribuídas em dois tratamentos: (1) suplemento sem inclusão de lipídios (CONT, n = 6) e (2) suplemento contendo 47,2 g Ca-SCACL/kg (para proporcionar uma ingestão de 0,2 kg Ca-SCACL/ dia) com base na matéria seca (n = 9). Os animais foram submetidos a 2,53 ± 1,35 rodadas consecutivas de aspiração folicular a intervalos de 27,65 ± 21,72 dias. Os oócitos foram avaliados morfologicamente, selecionados, maturados, fertilizados e cultivados para produção de embriões in vitro. Em seguida, os embriões foram transferidos para receptoras previamente submetidas a um protocolo de transferência de embriões em tempo fixo. O número de oócitos aspirados, a proporção de oócitos viáveis, a taxa de clivagem, a porcentagem de embriões, a taxa de prenhez e a proporção de sexo de embriões não foram afetados quando as vacas Nelore foram suplementadas com Ca-SCACL de óleo de soja em comparação com as vacas Nelore não suplementadas. Em conclusão, nossos resultados sugerem que suplemento contendo 47,2 g de Ca-SCACL/kg (para fornecer uma ingestão de 0,2 kg de Ca-SCACL) não afeta a produção in vitro de embriões de vacas Nelore em lactação. No entanto, novos estudos utilizando doses mais altas de gordura na dieta poderiam ser úteis para determinar o seu potencial sobre produção embrionária in vitro.

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OBJECTIVE: In vitro maturation has been shown to influence gene expression in oocytes, but a common shortcoming in reports on the matter has been the use of different donors in each experimental group thus disregarding donor effects. This study aimed to investigate the abundance of mRNA in oocytes matured in vivo and in vitro obtained from the same group of donors. METHODS: A bovine model was used to assess the relative abundance of specific transcripts in in vitro-matured (IN VITRO-OPU) and in vivo-matured (IN VIVO-OPU) oocytes collected from the same donors by transvaginal ovum pick-up (OPU). Transcript abundance in oocytes from the IN VIVO-OPU group and oocytes matured in vitro but retrieved from different cows slaughtered at a commercial abattoir (IN VITRO-Abattoir group) was also compared. Total RNA was extracted from denuded oocytes and cDNA was produced via reverse transcription using an oligo(dT) primer for relative quantification of eight target transcripts by real-time PCR. RESULTS: Oocytes in the IN VITRO-OPU group had lower (p<0.05) abundance of peroxiredoxin 1 (Prdx1), heat shock protein 70.1 (Hsp70.1), growth and differentiation factor 9 (Gdf9), and maternal antigen that embryo requires (Mater) transcripts than the oocytes in the IN VIVO-OPU group, all obtained from the same pool of donor cows. Similar results were seen in the comparisons involving the IN VIVO-OPU and IN VITRO-Abattoir groups (p<0.05). CONCLUSION: In vitro maturation affected the abundance of polyadenylated transcripts in the oocyte cytoplasm when compared to in vivo maturation induced by exogenous hormones in oocytes collected from the same donor pool.

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The main objective of this study was to verify genetic trends for milk production (MY305) and age at first calving (AFC). Were also considered levels of inbreeding practiced in the Brazilian dual-purpose Guzerá population (TPOP) comparing it with the same parameters estimated for two sub-populations derived from the reference (TPOP): female donors submitted to ovum-pick up (DPOP) and in vitro embryos produced (EPOP) between 2003 and 2013. Estimated breeding values (EBV) and inbreeding coefficients (F) were regressed by the year of birth (or year of in vitro fertilization) of each animal or embryo in order to obtain annual trends for these parameters separately for each of the three populations studied. A positive quadratic (ß2 = +0.000075) effect was detected for the F values in TPOP. Both DPOP and EPOP showed positive linear coefficients (ß1), respectively, +0.00084 (P < 0.001) and +0.00024 (P > 0.05). Annual mean F for EPOP was higher than TPOP and DPOP through the time series studied. The frequency of individuals with more than 7% F was higher in DPOP. Genetic trends for AFC were -0.187 days/year (P > 0.05); -0.557 days/year (P < 0.05) and -1.48 days/year (P < 0.05), respectively for TPOP; DPOP and EPOP. Genetic trends for MY305 were +6.75 kg/year (P < 0.001); +8.2 kg/year (P < 0.001) and +10.5 kg/year (P < 0.05), respectively for TPOP; DPOP and EPOP. For both traits analyzed, EPOP showed the highest regression coefficients, which confirms a higher selection pressure and lower generation intervals previously expected from this sub-population. Results reported in the present study suggest that mean F is increasing in the Guzerá population. Efforts for controlling inbred mating on in vitro fertilization should be considered, as the presence of a bottleneck effect seems to be getting shape on DPOP and EPOP.

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