Cow Embryos Research Articles

Effects of Short-Term Differences in Concentrate Feeding on the Recovery of In Vivo Embryos in Hanwoo Donor Cows through Superovulation Treatment.

Superovulation is a technique used to increase the number of oocytes released for fertilization. This study investigated the effects of short-term differences in concentrate feed intake on in vivo embryo production through superovulation in indigenous Korean (Hanwoo) cows. The cows were given fresh water and hay ad libitum and randomly divided into three groups (control (CON, n = 9): 2.0 kg/day (unchanged diet); low concentrate (LC, n = 10): 0 kg/day; and high concentrate (HC, n = 8): 4.0 kg/day) according to the amount of formula they were fed. This feeding treatment began seven days before the start of the hormonal treatment for superovulation. From the results, the LC group had the greatest weight change and the lowest body condition score at harvest, followed by the CON and HC groups (p < 0.05). The LC group had the highest number of harvesting embryos, followed by the HC and CON groups (p < 0.05). Estradiol, progesterone, glucose, total cholesterol, high-density lipoprotein, low-density lipoprotein, total protein, and blood urea nitrogen concentrations did not differ between the groups, except for a temporary increase in the HC group on day 0. These findings suggest that more embryos may be harvested when short-term changes in concentrate intake are made during superovulatory responses in Hanwoo cows.

Neospora caninum is not transmissible via embryo transfer, but affects the quality of embryos in dairy cows

The aim of this study was to evaluate embryo transfer in cattle as a pathway of transmitting neosporosis and to quantitatively and qualitatively compare the embryo production from seropositive and seronegative donors. Superovulatory treatments were performed on eight Girolando donors (four seropositive and four seronegative for N. caninum), resulting in the recovery of ninety-one structures (embryos and non-fertilized structures). Embryos collected and classified as viable were transferred to seronegative recipients and analyzed by PCR to identify N. caninum. No difference was observed in the number of structures collected from seropositive and seronegative donors (40 and 51; P = 0.64). There was a significant difference in the percentages of freezable (25 % and 74 %, P = 0.04) and transferable (27.5 % and 78.4 %, P = 0.003) embryos. The recipients had similar pregnancy rates (60 % and 57.1 %, P = 0.97) and pregnancy loss (50 % and 43.8 %, P = 0.58). There was no change in the serological status of the recipients, and no protozoan DNA was identified in none of the samples. It was concluded that the embryo transfer technique is safe regarding the transmission of neosporosis; however, the quality of embryo production was compromised from donors seropositive for N. caninum.

Early Embryonic Development in Agriculturally Important Species.

The fertilization of oocytes ovulated by pigs, sheep, cows, and horses is not considered a limiting factor in successful establishment of pregnancy. Pig, sheep, and cow embryos undergo cleavage to the blastocyst stage, hatch from the zona pellucida, and undergo central-type implantation. Hatched blastocysts of pigs, sheep, and cows transition from tubular to long filamentous forms to establish surface area for exchange of nutrients and gases with the uterus. The equine blastocyst, surrounded by external membranes, does not elongate but migrates throughout the uterine lumen before attaching to the uterine luminal epithelium (LE) to begin implantation. Pregnancy recognition signaling in pigs requires the trophectoderm to express interleukin 1 beta, estrogens, prostaglandin E2, and interferon gamma. Sheep and cow conceptus trophectoderm expresses interferon tau that induces interferon regulatory factor 2 that inhibits transcription of estrogen and oxytocin receptors by uterine epithelia. This prevents oxytocin-induced luteolytic pulses of prostaglandin F2-alpha from regressing the corpora lutea, as well as ensuring the secretion of progesterone required for maintenance of pregnancy. The pregnancy recognition signal produced by equine blastocysts is not known. Implantation in these species requires interactions between extracellular matrix (ECM) proteins and integrins as the conceptus undergoes apposition and firm attachment to the uterine LE. This review provides details with respect to early embryonic development and the transition from spherical to filamentous conceptuses in pigs, sheep, and cows, as well as pre-implantation development of equine blastocysts and implantation of the conceptuses.

Sexual dimorphic miRNA-mediated response of bovine elongated embryos to the maternal microenvironment.

A skewed male-to-female ratio in cattle is believed to be due to the biased embryo losses during pregnancy. The changes in biochemical secretion such as miRNAs by the embryo due to altered maternal environment could cause a sex biased selective implantation resulting in a skewed male to female ratio at birth. Nevertheless, it is still not clear whether the male and female embryos could modify their miRNA expression patterns differently in response to altered physiological developmental conditions. Therefore, this study was focused on identifying sex specific miRNA expression patterns induced in the embryo during the elongation period in response to the maternal environment. For this, in vitro produced day female and male embryos were transferred to Holsteins Frisian cows and heifers. The elongated female and male embryos were then recovered at day 13 of the gestation period. Total RNA including the miRNAs was isolated from each group of elongated embryo samples were subjected to the next generation miRNA sequencing. Sequence alignment, identification and quantification of miRNAs were done using the miRDeep2 software package and differential miRNA expression analyses were performed using the edgeR bioconductor package. The recovery rate of viable elongating embryos at day 13 of the gestation period was 26.6%. In cows, 2.8 more viable elongating male embryos were recovered than female embryos, while in heifers the sex ratio of the recovered elongating embryos was close to one (1.05). The miRNA analysis showed that 254 miRNAs were detected in both male and female elongated embryos developed either in cows or heifers, of which 14 miRNAs including bta-miR-10b, bta-miR-148a, bta-miR-26a, and bta-miR-30d were highly expressed. Moreover, the expression level of 32 miRNAs including bta-let-7c, bta-let-7b, bta-let-7g, bta-let-7d and bta-let-7e was significantly different between the male and female embryos developed in cows, but the expression level of only 4 miRNAs (bta-miR-10, bta-mR-100, bta-miR-155 and bta-miR-6119-5p) was different between the male and female embryos that were developed in heifers. Furthermore, 19 miRNAs including those involved in cellular energy homeostasis pathways were differentially expressed between the male embryos developed in cows and heifers, but no significantly differentially expressed miRNAs were detected between the female embryos of cows and heifers. Thus, this study revealed that the sex ratio skewed towards males in embryos developed in cows was accompanied by increased embryonic sexual dimorphic miRNA expression divergence in embryos developed in cows compared to those developed in heifers. Moreover, male embryos are more sensitive to respond to the maternal reproductive microenvironment by modulating their miRNA expression.

70 Possibility for genomic evaluation using single blastomeres derived from 8-cell stage IVP embryos in Japanese Black cows

70 Possibility for genomic evaluation using single blastomeres derived from 8-cell stage IVP embryos in Japanese Black cows

LIF regulates the expression of miR-27a-3p and HOXA10 in bovine endometrial epithelial cells via STAT3 pathway

LIF is crucial in regulating embryo implantation, while HOXA10 is a marker gene for uterine receptivity. However, the specific mechanism of LIF regulating HOXA10 during cow embryo implantation has not been fully understood. To address this knowledge gap, the experiment involved treating bovine endometrial epithelial cells (BEECs) with LIF to investigate the relationship between LIF, miRNA, and HOXA10. The experimental findings revealed that applying LIF resulted in a substantial increase in the proliferation of endometrial epithelial cells. Moreover, the expressions of PI3K, AKT, HOXA10, CDK4, cyclinD1, and cyclinE1 were significantly elevated. Conversely, the expression of p21Cipl was significantly reduced. In the group that received a combination of LIF and a STAT3 inhibitor, the expression of PI3K/AKT remained significantly increased, but there was no significant change in the expression of HOXA10. When miRNA-27a-3p was overexpressed, it resulted in a decrease in both the RNA and protein expression of HOXA10. Conversely, inhibiting miRNA-27a-3p increased the RNA and protein expression of HOXA10. In the presence of LIF treatment, the expression of miRNA-27a-3p was reduced, while the expression of HOXA10 was increased. However, when LIF and a STAT3 inhibitor were combined, there was no significant change in the expression of miRNA-27a-3p or HOXA10. Consequently, LIF facilitated cell proliferation by activating the PI3K/AKT pathway. LIF controlled the expression of miRNA-27a-3p and HOXA10 in endometrial epithelial cells through STAT3, with miRNA-27a-3p negatively regulating the expression of HOXA10.

Effect of a neurokinin 3 receptor-selective agonist administration on the embryos recovered from superovulated cows.

Superovulation (SOV) treatment of cows results in unovulated follicles and inconsistent quality of the recovered embryos. It has been demonstrated that luteinizing hormone (LH) secretion is suppressed during SOV treatment of cows, which may cause insufficient follicle development and variation in the development of recovered embryos and unovulated follicles. Pulsatile gonadotropin-releasing hormone/LH secretion is controlled by the activity of kisspeptin, neurokinin B and dynorphin (KNDy) neurons in the arcuate nucleus in many mammals. As neurokinin B promotes the activity of KNDy neurons, we hypothesized that senktide, a neurokinin B receptor agonist, has the potential as a therapeutic drug to improve the ovulation rate and quality of recovered embryos in SOV-treated cows via stimulation of LH secretion. Senktide was administered intravenously (30 or 300nmol/min) for 2h, beginning from 72h after the start of SOV treatment. LH secretion was examined before and after administration, and embryos were collected 7 d after estrus. Senktide administration increased LH secretion in SOV-treated cows. The ratios of code 1, code 1 and 2, and blastocyst stage embryos to recovered embryos were increased by senktide (300nmol/min) administration. Moreover, the mRNA levels of MTCO1, COX7C, and MTATP6 were upregulated in recovered embryos of senktide (300nmol/min)-administered animals. These results indicate that the administration of senktide to SOV-treated cows enhances LH secretion and upregulates the expression of genes involved in mitochondrial metabolism in embryos, thereby improving embryo development and embryo quality.

Results of transplantation of embryos of the Simmental breed

The selection of offspring from the desired sex can be one of the determining factors to increase the genetic progress and farmer´s profitability in either beef or dairy cattle. This study’s objective was to determine the impact of two approaches of artificial insemination on embryo-productivity and transplantation of cow embryos. We used as a model the symmental breed, bred in Kazakhstan’s Northeast region. The quantity and quality of embryos obtained by artificial insemination of donor cows with same-sex and ambisexual semen were evaluated. In particular, the study examined the embryo transfer process from artificial insemination of ambisexual semen, embryo transfer from cow donors, washing out, evaluation, and transfer to recipients.This study shows that ambisexual inseminationresulted in an average 61.3% more suitable embryos than same-sex insemination. Additionally, embryos from ambisexual fertilization are more likely to reach the early blastocyte stage (59.8±4.18%). Despite that, there is no change in the success of embryo transplantation. In summary, creating conditions close to natural ones improves the success rate of embryo transfer.

Beef embryos in dairy cows: feedlot performance, mechanistic responses, and carcass characteristics of straightbred Holstein calves and Angus-sired calves from Holstein, Jersey, or crossbred beef dams.

Improved reproductive management has allowed dairy cow pregnancies to be optimized for beef production. The objective of this sire-controlled study was to test the feedlot performance of straightbred beef calves raised on a calf ranch and to compare finishing growth performance, carcass characteristics, and mechanistic responses relative to beef × dairy crossbreds and straightbred beef cattle raised in a traditional beef cow/calf system. Tested treatment groups included straightbred beef steers and heifers reared on range (A × B; n = 14), straightbred beef steers and heifers born following embryo transfer to Holstein dams (H ET; n = 15) and Jersey dams (J ET; n = 16) The finishing trial began when cattle weighed 301 ± 32.0 kg and concluded after 195 ± 1.4 d. Individual intake was recorded from day 28 until shipment for slaughter. All cattle were weighed every 28 d; serum was collected from a subset of steers every 56 d. Cattle of straightbred beef genetics (A × B, H ET, and J ET) and A × H were similar in final shrunk body weight, dry matter intake, and carcass weight (P > 0.05 for each variable). Compared with A × J cattle, J ET was 42 d younger at slaughter with 42 kg more carcass weight (P < 0.05 for both variables). No difference was observed in longissimus muscle area between all treatments (P = 0.40). Fat thickness was greatest for straightbred beef cattle, least for A × J cattle, and intermediate for A × H cattle (P < 0.05). When adjusted for percentage of adjusted final body weight, feed efficiency was greater for straightbred beef cattle compared with beef × dairy crossbred cattle (P = 0.04). A treatment × day interaction was observed for circulating insulin-like growth factor I (IGF-I; P < 0.01); 112 d after being implanted, beef × dairy crossbred cattle had greater circulating IGF-I concentration than cattle of straightbred beef genetics (P < 0.05). Straightbred beef calves born to Jersey cows had more efficient feedlot and carcass performance than A × J crossbreds. Calves of straightbred beef genetics raised traditionally or in a calf ranch performed similarly in the feedlot.

Beef embryos in dairy cows: calfhood growth of Angus-sired calves from Holstein, Jersey, and crossbred beef dams.

Improved reproductive management has allowed dairy cow pregnancies to be optimized for beef production. The objective of this sire-controlled study was to characterize the effects of beef or dairy maternal genetics and the dairy management system on calf growth. Pregnancies were created with a 2 × 2 factorial arrangement of dam breed (Holstein or Jersey) and mating type (artificial insemination or implantation of an in vitro produced embryo from a commercial beef cow oocyte). Resulting calves were reared in a calf ranch. Additionally, commercial beef cows were inseminated and reared resulting calves on range. Therefore, the five treatments were Angus × Holstein (A × H; n = 19), Angus × Jersey (A × J; n = 22), Angus × beef gestated by Holstein (H ET; n = 18), Angus × beef gestated by Jersey (J ET; n = 8), and Angus × beef raised by beef (A × B; n = 20). Beginning at birth, calf body weight, cannon circumference, forearm circumference, top width, hip width, and hip height were measured approximately every 28 d until ~196 d of age. At birth, A × J calves weighed the least (P < 0.01). At 150 d of age, body weight was greatest (P < 0.05) among A × B calves, intermediate among H ET and A × H calves, and least among J ET and A × J calves (P < 0.05). Morphometric differences were detected between treatments (multivariate analysis of variance, P < 0.01). Primary discriminant function scores identified A × B calves having lesser values than A × J or A × H calves (analysis of variance [ANOVA], P < 0.01); A × B calves had greater cannon circumference, greater top width, and less hip height (standardized loadings of -0.47, -0.48, and 0.63, respectively). Secondary discriminant function scores identified J ET and H ET to have greater forearm circumference-a key indicator of muscling-than A × J or A × H (ANOVA, P < 0.01; standardized loading of 0.99). The dairy management system limited growth rate of beef genetics compared to the beef management system. In addition, Holstein dams transmitted greater growth potential than Jersey dams. Replacing maternal dairy genetics with beef genetics moderated frame size and created a more muscular phenotype.

ZFP57 regulates DNA methylation of imprinted genes to facilitate embryonic development of somatic cell nuclear transfer embryos in Holstein cows.

Aberrant epigenetic nuclear reprogramming, especially imprinting pattern disorders, is one of the major causes of failure of clone development from somatic cell nuclear transfer (SCNT). Previous studies showed that ZFP57 is a key protein required for imprint maintenance after fertilization. In this study, we found that imprinting control regions in several imprinted genes were significantly hypomethylated in cloned embryos compared with in vitro fertilization embryos, indicating a loss of imprinted gene methylation. The ZFP57 expression was capable of maintaining the correct degree of methylation at several imprinting control regions and correcting abnormal hypomethylation. Moreover, we successfully obtained bovine fetal fibroblasts overexpressing ZFP57, which were used as donors for SCNT. Our results demonstrated that overexpression of ZFP57 increased total and trophectoderm cell numbers and the ratio of inner cell mass to total cells, reduced the apoptosis rate and significantly enhanced the development of SCNT blastocysts in vitro, ultimately achieving a degree of methylation similar to that in in vitro fertilization embryos. We concluded that overexpression of ZFP57 in donor cells provided an effective method for enhancing nuclear reprogramming and developmental potential in SCNT embryos. The ZFP57 protein played a key role in maintaining the methylation of imprinted genes during early embryonic development, which may be effective for enhanced SCNT in cattle.

Interspecific Nuclear Transfer Blastocysts Reconstructed from Arabian Oryx Somatic Cells and Domestic Cow Ooplasm.

Cloning, commonly referred to as somatic cell nuclear transfer (SCNT), is the technique of enucleating an oocyte and injecting a somatic cell into it. This study was carried out with interspecific SCNT technology to clone the Arabian Oryx utilizing the oryx's fibroblast cells and transfer it to the enucleated oocytes of a domestic cow. The recipient oocytes were extracted from the cows that had been butchered. Oryx somatic nuclei were introduced into cow oocytes to produce embryonic cells. The study was conducted on three groups, Oryx interspecific somatic cell nuclear transfer into enucleated oocytes of domestic cows, cow SCNT "the same bovine family species", used as a control group, and in vitro fertilized (IVF) cows to verify all media used in this work. The rates of different embryo developmental stages varied slightly (from 1- cell to morula stage). Additionally, the oryx interspecies Somatic cell nuclear transfer blastocyst developmental rate (9.23%) was comparable to that of cow SCNT (8.33%). While the blastula stage rate of the (IVF) cow embryos exhibited a higher cleavage rate (42%) in the embryo development stage. The results of this study enhanced domestic cow oocytes' ability to support interspecific SCNT cloned oryx, and generate a viable embryo that can advance to the blastula stage.

Characteristics of cytotoxicity of native zeolite against cattle epithelial cells

Relevance. In recent years, there has been an increasing interest in the study of trepel, the mass fraction of zeolite in which reaches 50%. The purpose of this study was to assess the cytotoxic effect of the Zikeyevsky field trepel on the cells of the cow embryo lung (CEL).Methods. To characterize cytotoxicity, 6 fractions of trepel were selected (mining quarry — Zikeyevskoye deposit of Zhizdrinsky district of Kaluga region) with particle sizes: no. 1 — 0.03 mm, no. 2 — 0,03–0,06 mm, no. 3 — 0,09–0,15 mm, no. 4 — 0,15–0,3 mm, no. 5 — 0,3–0,5 mm. To determine cytotoxicity, zeolite suspensions were prepared on a DMEM maintenance medium in concentrations 50, 100, 200, 300, 400, 500, 1000 micrograms/ ml. As a model for determining the toxicity of trepeles, a transplanted cell line of CEL (epithelium of the lung embryo of a cow) obtained from a Collection of vertebrate cell cultures (ICiG RAS, Russia) was selected. The cells were grown on a DMEM medium with the addition of 10% fetal bovine serum ("HyClone", USA), penicillin and streptomycin (100 IU/ml each), 20 mM glutamine ("Sigma-Aldrich", USA) in 96-well tablets ("Costar", USA) at +37 °C in an atmosphere of 5% CO2. Cell viability was assessed by the activity of mitochondrial dehydrogenase according to the standard method. Statistical data processing was performed using "GraphPad Prism 6.0" software (USA). The experiments were carried out in 5 repeats, p ≤ 0.05 was taken as a statistically significant level.Results. It was found that concentrations of all fractions of trepels up to 100 micrograms/ml do not have a cytotoxic effect on the studied cells. A significant cytopathogenic effect is manifested in the concentration range of 300–1000 micrograms/ml; is in a positive correlation with the size of trepel particles — the proportion of necrotic cells when processing monolayers with maximum concentrations is up to 99.7±2.9%, which may be due to the mechanical effect of large mineral particles on cellular structures.

The Influence of Platelet Concentrate on the Development of Cattle Embryos in аn In Vitro System

There are many studies on the improvement of the conditions for cultivating bovine embryos in vitro. However, the issue of co-cultivation of platelets and cow embryos is understudied, although platelet activation leads to the release of a considerable amount of biologically active substances into the culture medium and their co-cultivation with embryos can positively affect the growth and development of the latter. Therefore, the purpose of this study was to investigate the effect of different platelet concentrations in the in vitro culture system on the development of cow embryos. Fertilized zygotes (total number 180) were divided into 5 groups: Group 1 – culture medium without platelet addition (control); Group 2 – medium for cultivation with the addition of 10×106 platelets/cm3 ; Group 3 – final concentration in the system is 20×106 platelets/cm3 ; Group 4 – 50×106 platelets/cm3 ; Group 5 – 100×106 platelets/cm3 . According to the results, it was found that co-cultivation of embryos with platelets in the in vitro system is effective. Thus, a correlation was found between improved embryo development indicators and an increase in platelet concentration. The optimal platelet concentration was 50×106 /cm3 , which allowed obtaining a 13.9% higher level of blastulation, 15.7% higher average embryo size, and 2.5% higher average number of cells in the blastocyst compared to the control. At the same time, the platelet concentration of 100×106 /cm3 led to a significant decrease in the indicators under study, compared with the group without platelets. Therefore, co-cultivation of cow embryos with platelets is advisable since it allows improving the development indicators of cow embryos. The data analysed and presented in this paper will increase the efficiency of cultivation of bovine embryos for both scientific and industrial purposes

Characteristics of cytotoxicity of native zeolite against cattle epithelial cells

Relevance. Special attention of researchers is attracted by zeolites — minerals of the family of aluminosilicates of alkaline and alkaline earth metals. Considering that the composition of zeolites is extremely variable, including the content of trace elements, most zeolite tuffs of Russian Federationare not evaluated in terms of possible cytotoxicity. The aim of this study was to characterize the cytotoxicity of native clinoptilolite against epithelial cells of cattle.Methods. To characterize cytotoxicity, 5 fractions of native clinoptilolite (mining quarry — Drozhzhanovsky district of the Republic of Tatarstan) with particle sizes were selected: No. 1 — 0.2 mm, No. 2 — 0.24 mm, No. 3 — 0.8 mm, No. 4 — 0,8–2,5 mm, No. 5 — 2,5–5,0 mm. Two transferable cell lines were selected as models for determining the toxicity of zeolites: LEK (epithelium of the lung of a cow embryo) and TR (tracheal epithelium of a cow embryo) obtained from a Collection of vertebrate cell cultures (ICiG RAS, Russia). MTTtestwas carried out. Cell viability was assessed by the activity of mitochondrial dehydrogenase according to a standard method. Statistical data processing was performed using “GraphPad Prism 6.0” software (USA). The experiments were carried out in 5 repetitions, p ≤ 0.05 was taken as a statistically reliable level.Results. It was found that concentrations up to 300 micrograms/mlof all fractions of zeolites do not have a cytotoxic effect on the studied cells. The cytopathogenic effect manifests itself in the concentration range of 400-1000 micrograms/ml and is in direct correlation with the size of zeolite particles — the proportion of cells in the state of apoptosis is up to 35.23±2.3%, which is probably due to the mechanical effect of large particles of the rocks in question on cellular structures. Information about the cytotoxic effects of different types of zeolites on the cells of the body of productive animals will later form the basis of their toxicological assessment and will allow us to develop a strategy for their safe use.

Specifics of vitrification of in vitro-produced cattle embyos at various development stages

Producing embryos in vitro is an important technology used to improve the genetic potential of cattle and perfect the programs of their breeding. Regardless of the way they are produced, all embryos that had not been used for transplantation to recipients must be conserved. Because of significantly increased interest in the problem of cryoconservation of embryos, both coming from scientists and businesses, there are emerging new commercial environments that allow the facilitation of cryoconservation and the increase in the embryo survival. Oocyte-cumulus complexes obtained from the ovaries of slaughtered clinically healthy cows matured in 22–24 h in in vitro conditions. The oocytes were co-cultured with spermatozoids in Fertilization medium, and the obtained zygotes were cultured in Culture medium with Sodium-Pyruvate for 4 or 7 days up to the stage of morula or blastocyste, respectively. For the vitrification of cow embryos, we used a commercial kit for the vitrification of human embryos, having compared the duration of equilibration. According to the results of the studies, we observed high efficiency of cryoconservation of cow embryos using the commercial kit for vitrification of human embryos. The results revealed the significant effect of equilibration on survival and further development of embryos. In addition, we described the dependence of development stage of cattle embryo on the duration of the contact of embryo with equilibration solution. Therefore, optimal time of contact of cattle embryos at the morula stage with equilibration solution was 12 minutes. On the 24th h after thawing, 46.7 ± 3.3% of the embryos were observed to undergo blastulation, and on 48th h, this parameter increased to 96.7 ± 3.3%, which corresponded to the parameters in the group of embryos that had not been subjected to cryoconservation. In the conditions of further cultivation, the percentage of blastocystes that hatched in the experimental group was no different from that of the control. At the same time, the highest efficiency of vitrification of blastocystes of cows was seen after the contact with the equilibration solution for 15 min, since the percentage of hatched blastocystes was the same as in the control group. Therefore, using the commercial kit for vitrification of human embryos is beneficial, for it promotes the parameters of cow embryos after vitrification/thawing that are similar to such of intact embryos (without freezing). The data we analyzed and presented in the paper could help to increase the efficiency of cryoconservation of cattle embryos for both scientific and commercial purposes.

DEVELOPMENT OF THE TECHNOLOGY OF FIBROBLAST ISOLATION FOR REGENERATIVE THERAPY IN ANIMAL

The article describes the methods of isolation of fibroblasts from the musculoskeletal tissue of a cow embryo for practical use in veterinary medicine as part of the application of new medical technologies. The morphological characteristics and functional activity were studied the viability of musculocutaneous fibroblasts was assessed.

Corn or wheat-based diet to manipulate lipid content in early embryos of Jersey cows

Numerous field observations and previous reports have described a breed effect on embryonic survival to cryopreservation. Embryos collected from Jersey cows show a poor survival rate compared to Holstein embryos due to their rich intracellular lipid content. Less well documented in the scientific literature, but also reported from field observations, it was proposed that survival rates can be improved by removing corn from the feedstuff. This project was aimed to test whether corn replacement would modify intracellular lipid content in Jersey cow embryos. Non-lactating purebred Jersey cows were fed with an isoenergetic diet supplemented with either corn or wheat. Embryos were collected in vivo following ovarian stimulation and insemination. Results show only marginal impact on blood lipids. Overall, embryos were morphologically indistinguishable. Some lipids known to be associated with lower cryotolerance were significantly impacted by the treatment namely triacylglycerol, sphingomyelin and phosphatidylcholine. Corn supplementation significantly diminished mitochondrial activity in blastomeres. These treatment effects suggest an indirect mechanism potentially impacting embryo quality through mitochondrial dysfunction rather than direct lipid uptake.

Influence of PMSG on Superstimulation and Embryo Development Following Somatic Cell Nuclear Transfer in Holstein Cows in the United Arab Emirates.

The present study investigated the effect of superstimulation to improve in vitro embryo production in the Gulf area, where the temperature is high. Holstein cows were classified into the control and superstimulation groups. Superstimulation was induced with a single intramuscular injection of pregnant mare serum gonadotropin (PMSG; 2500 IU) on day 14 of the estrus cycle (day 0; estrus). The development of follicles was evaluated by ultrasonography of the ovaries daily. At 40 h after the PMSG injection, oocytes were collected by the ovum pick-up (OPU) technique. OPU was performed at the same stage of the estrus cycle in the control group as in the superstimulation group. The number of follicles with a diameter of more than 6 mm and the number of retrieved cumulus-oocyte complexes were significantly higher in the superstimulation group than in the control group. Furthermore, the maturation rate was higher in the superstimulation group than in the control group. Cloned embryos were produced by somatic cell nuclear transfer using matured oocytes. The cleavage and blastocyst formation rates were significantly higher in the superstimulation group than in the control group. In conclusion, a single injection of PMSG can facilitate the efficient production of cloned cow embryos.

Influência do estresse calórico na produção in vitro de oócitos e embriões de vacas Holandesas de alta produtividade

Abstract 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.