ASSESSMENT OF MOUSE EMBRYO VIABILITY BY ESTERASIC ACTIVITY DETECTION

In order to evaluate the esterasic activity within the viable embryos we used the Fluorescein diacetate(FDA) staining test. For staining was used a 0.5 mg/ml FDA stock solution. The embryos were recoveredat 48 hours post coitus from superovulated Swiss mouse females. Before staining the embryos weremicroscopically evaluated by morphological criteria and classified in 4 quality codes. The two methodsused for quality and viability assessment were correlated applying Pearson coefficient. The calculatedvalue of the Pearson coefficient (r=1) showed a strong correlation between the two methods used andindicate FDA staining test and esterasic activity as a fast, easy and reliable method for embryo viabilityassessment

EXPERIMENTAL TRIES TO ESTABLISH THE PREIMPLANTATIONAL MAMMALIAN EMBRYOS VIABILITY THROUGHOUT STAINING

Presently there are more methods to assess embryo quality but, still the wieldy usedremains the morphological criteria method. In this experiment were tested twostaining methods for embryos and oocytes. The embryos were recovered from mousefemale at 72 hours after mating. The recovered embryos were first evaluated aftermorphological criteria and than by Trypan blue exclusion and Neutral red staining.Using Trypan blue exclusion were evaluated 30 embryos from which 19 (63.3) wereclassified as viable and 11 (36.7) were classified as nonviable. By Neutral redstaining were evaluated 37 embryos from which 24 (64.8) were considered viableand 13 (35.2) were considered nonviable. The oocytes recovered were alsoevaluated using the two methods: using Trypan blue exclusion were stained 10oocytes from which 9 remained uncolored and were considered viable and 1 wasstained in blue and was considered nonviable and using Neutral red 13 oocytes werestained from which 9 were evaluated as viable and 4 as nonviable

THE INFLUENCE OF THE PUERPERAL AFFECTIONS ON INSEMINATION INDEX AND UTERINE REPOSE IN COWS

The observations were made, through a year, at SD Timisoara on cows fromHolstein-Friesian and Fleckvieh breed. The puerperal period was observed, theincidence of the endometrites was recorded and there were calculated tworeproduction parameters: the Insemination Index (Ig) and the Uterine Reposeduration (UR) (Open days). The Insemination Index (service/conception) (Ig)represents the mean number of artificial inseminations performed in order to obtaina pregnancy. Uterine Repose represents the time interval, in days, from calving untilthe fecund insemination. The Uterine Repose has two components: VoluntaryWaiting Period (VWP) (time interval from calving until the introduction of thefemale to reproduction) and Service Period (SP) (time interval from the end of theVWP until the fecund insemination). There were noticed that the incidence of theuterine infections were significant higher (p<0.05) at cows from Holstein-Friesianbreed (63.3%), compared to the cows from Fleckvieh breed (41.3%). TheInsemination Index was significant lower (p<0.05) at cows without uterine infections(1.9), compared to the cows with uterine infections (2.5). The mean duration of theUterine Repose was significant lower (p<0.05) at healthy cows (114.7 days),compared with cows with uterine infections after calving (182.2 days). It seams thatthe cows from Fleckvieh breed are more resistant to the exploitation conditions formilk production than compared with cows from Holstein-Friesian breed

EFFECT OF CZB CULTURE MEDIA ON IN VITRO DEVELOPMENT OF CLONED MOUSE EMBRYOS

The effect of simple and sequential embryo culture media on the preimplantationdevelopment of mouse nuclear transfer (NT) embryos reconstructed with cumuluscell nuclei using a mechanical NT technique was studied. Blastocyst formation ratewas evaluated using CZB medium. Nonmanipulated and sham-manipulatedparthenogenetic embryos served as controls for, respectively, the medium and thehandling technique. Rates of blastocyst formation for medium and handling controlembryos were similar in CZB (50% and 53%). Development of NT embryos wassignificantly impaired from the two-cell stage onwards, reaching the blastocyst stage ata rate of 4% in CZB. These data demonstrate not only that NT embryos are moresensitive to in vitro culture conditions than parthenogenetic control embryos but alsothat selection of culture media can influence the preimplantation development of NTembryos

RESEARCHES REGARDING THE INFLUENCE OF THE NUMBER OF CUMULAR CELLS LAYER OVER THE OOCYTE MATURATION EFFICIENCY

During the experiments we have carried out with imature oocyte collected from the ovarian follicles, wefound a variety of oocyte-cumulus complexes. We got the following experiment in order to understand therole of cumular cells on the achievement of the cytoplasma and oocyte nucleus maturation. We select theoocyte-cumulus complexes collected both from cows and sows according to the number of cumular celllayers and we watched their development to the blastocyst stade. Thus, we achieved three groups of COC(oocyte-cumulus complexes).One group was made of oocyte without cumular cells, the second group had a layer of cumular cells andthe third group had many layers of cumular cells. we performed an incubation of all these types of COCin TCM-199 enriched with 20% of bovine fetal serum. Because only 1,2 oocyte of the ones who lack thecumular cells layer had maturation signs during cultivation in the thermostat versus 55 and 115,respectively, of the ones that had many cellular layers, presents a solid evidence that cumular cells areindispensable for the maturation and even to the fecundation process. The cumular cells perform adecisive role on the cytoplasma and oocyte nucleus maturation process

Histomorphometric Features of Deltoid Muscle (Musculus Deltoideus) in the Mouflon (Ovis ammon musimon Pal.) and Domestic Sheep

The aim of this study was to determine histomorphometry of the skeletal muscle at rams from the Tigaie breed and males mouflon (Ovis ammon musimon Pal.) knowing that, in addition to a variety of factors, both the fiber thickness and muscle fascicles influence of meat quality. The study was conducted on the deltoid muscle fragments taken from five individuals of the each species. The muscle samples were processed according to the method of embedded in paraffin, sectioned to a thickness of 5 µm and stained with Mallory's trichrome method. From the histomorphometric analysis resulted that in mouflon, the average area of muscle fascicles is larger, as compared with the ram (p <0.05), the ratio between the fascicles muscle area and the interfascicular connective tissue being 2.939:1 to mouflon and 1,624:1 to ram. Also, at mouflon the muscle fibers are thicker, the area and perimeter  registering an average value of 486.60 μm2, respectively 82.83 μm while in the ram, the area of the muscle fibers is 281.56 μm2 and the perimeter of 62.92 μm (p <0.001). The amount of interfibrillar connective tissue is higher in the ram (p <0.05) and the ratio between the muscular fibers area and interfibrillar connective tissue area was 1.649:1 in mouflon and 1.451:1 at ram (p<0.05)

Slaughter Performance and Carcass Characteristics of the Hybrids Obtained by Crossbreeding between European Mouflon (Ovis ammon musimon Pal.) and Sheep Breed Tigaie

The aim of this work was to determine differences between slaughter performances and carcass characteristics of first generation hybrids (F1) obtained by crossbreeding between European Mouflon (Ovis ammon musimon Pal.) and the Romanian sheep breed Tigaie. To assess the yield at slaughter and the participation percentage of the cut parts from the whole carcass structure, crossbreeding were made between females of sheep breed Tigaie and males of mouflon (FT x MM) respectively between mouflon females and males of sheep breed Tigaie (FMxMT). At the age of 60 days 14 lambs were sacrificed (7 hybrids FTxMM and 7 hybrids FMxMT). Slaughter yield calculated on hot and chilled carcasses had higher values at FMxMT (P<0.05). The participation percentage of the cut parts from the whole carcass structure had the highest values at FMxMT hybrids compared to FTxMM hybrids. Results from this study showed that genotype significantly influenced the studied characteristics and have revealed the superiority of FMxMT hybrids as against FTxMM hybrids lambs

Reaction of cows ovaries to GnRH administration in different estrus cycle stages

Administration of GnRH in the luteal phase of estrous in dairy cows induces an increase of LH levels, with the modification of the growth waves of the ovarian follicles. GnRH induces ovulation or atresia of the dominant follicle and the recruitment of a new wave of follicular growth. The GnRH administration in the luteal phase of the estrous cycle induces growth waves synchronization of ovarian follicles, so that, a new wave of follicles started to grow at 5-6 days after administration. In our experiments, we administered 2ml Ovarelin (100 mcg GnRH), to three groups of cows (116 cows): in early luteal phase of the estrous cycle (days 4-5), in the middle of luteal phase (days 9-12), and late luteal phase (days 15-16). The rates of cows standing heat were 91.66% when GnRH was administered in early luteal phase, 95.22% when was administrated in the middle of luteal phase, and 73.68% in late luteal phase GnRH administration. After artificial insemination, the conception rates were 48.48% in early luteal phase, 52.5% at middle luteal phase and 46.42% in the late luteal phase of the estrous cycle