Effect of strategies to increase progesterone levels on fertility of bovine embryo transfer recipients - A meta-analysis.

The pregnancy rate following embryo transfer (ET) is a very important factor in the success of embryo production programs. Different strategies were therefore developed to increase pregnancy rates. The aim of this meta-analysis was to investigate the effects of hormone treatments used to increase the success of embryo transfer programs on pregnancy rates. A meta-analysis was performed of 46 trials from 39 publications involving treated (n = 7856) and control (n = 6663) cattle. The meta-analysis explained the effect size with its 95 % confidence interval (CI) for pregnancy per embryo transfer (P/ET) after hormonal treatment under different moderators. Hormonal support was found to increase P/ET compared to the control group (P < 0.05). However, GnRH treatment was found to increase P/ET by approximately 4.3 % and hCG treatment by 8.0 %. Progesterone supplementation was not found to have a statistically significant effect on P/ET. In addition, GnRH treatment significantly increased P/ET when used to transfer in vitro or frozen-thawed embryos or in studies using cows as recipients. It was observed that hCG treatment had a positive effect on P/ET according to all moderators. Progesterone supplementation significantly increased P/ET when frozen embryos were transferred and reduced P/ET, especially in publications where fresh or in vitro produced embryos were transferred or cows were used as recipients. The results of this meta-analysis showed that the use of GnRH, and hCG, in bovine embryo transfer programs increased P/ET, whereas the use of progesterone had no effect on P/ET. However, it was found that P/ET could increase/decrease depending on the moderator.

Effect of putrescine supplementation to in vitro maturation medium on embryo development and quality in cattle.

This study aimed to investigate the effect of putrescine supplementation to maturation medium during in vitro embryo production in cattle on maturation and embryo development/quality. Oocytes obtained from the ovaries of Holstein cattle were used in the study. Obtained cumulus-oocyte complexes were evaluated according to morphological structure, cytoplasmic features, and cumulus cell number, and only Category-I ones were used in the study. Before the in vitro maturation step, oocytes were randomly divided into two groups. In the first group (Putrescine group, n = 159), 0.5 mM putrescine was added to the maturation medium before in vitro maturation. No addition was applied to the maturation medium of the second group (Control group, n = 149). Cumulus expansion degrees of oocytes following maturation (Grade I: poor, Grade II: partial, and Grade III: complete) were determined. In addition, the meiosis of oocytes after maturation was evaluated by differential staining. Then the oocytes were left for fertilization with sperm and finally, possible zygotes were transferred to the culture medium. After determining the developmental stages and quality of the embryos after in vitro culture, only the embryos at the blastocyst stage were stained with the differential staining method to determine the cell numbers. When the cumulus expansion degrees of the groups were evaluated, the Grade III cumulus expansion rate in the putrescine group was higher than the control group (74.21% and 60.4%; respectively) and the Grade I expansion rate (11.95% and 26.17%; respectively) was found lower (p < .05). When the resumption of meiosis was evaluated according to the cumulus expansion degrees, it was determined that the rate of resumption of meiosis increased as the cumulus expansion increased. In addition, the cleavage rates of oocytes and reaching the blastocyst in the putrescine group were found to be higher than in the control group (p < .05). Moreover, inner cell mass, trophectoderm cells, and total cell counts were found to be higher in blastocysts obtained after the putrescine supplementation to the maturation medium compared to the control group (p < .05). As a result, it was determined that the putrescine supplementation to the maturation medium during in vitro embryo production in cattle increased the degree of cumulus expansion and the rate of resumption of meiosis. In addition, putrescine supplementation was thought to increase the rate of reaching the blastocyst of oocytes due to better cell development in embryos.

Does using microfluidic sperm sorting chips in bovine IVEP affect blastocyst development?

This study aimed to determine the effect of microfluidic sperm sorting chip on embryo development and quality in the sperm treatment step in in vitro embryo production in cattle. Only A-quality oocytes obtained from the ovaries of Holstein cattle were included in the study. These oocytes were first placed in in vitro maturation medium, and matured oocytes were randomly divided into two groups at the 24th hour of maturation. Oocytes in the first group with the Microfluidic Sperm Sorting Chip (MFSC, n = 154) were put into a fertilization medium with spermatozoa prepared with microfluidic sperm sorting device. Oocytes in the second group (Con, n = 169) were fertilized with spermatozoa prepared by the routine sperm treatment step of the commercial company. The rate of cleavage (85.71% vs. 76.33%, respectively) and of reaching the blastocyst (44.15% vs. 32.54%, respectively) in the MFSC group were higher than the control group. In addition, it was determined that the numbers of ICM (45.8 ± 2.04 vs. 39.2 ± 1.85, respectively), TE (122.13 ± 2.19 vs. 115.0 ± 2.61, respectively), TC (167.93 ± 2.89 vs. 154.2 ± 2.62, respectively) increased in the MFSC group compared to the control group. A statistically significant difference was found in the number of cells with apoptosis per embryo (5.14 ± 0.77 vs. 11.91 ± 0.79) and apoptotic index rates (3.06 ± 0.47 vs. 7.72 ± 0.55%) of the MFSC and Con groups. As a result, we concluded that using microfluidic sperm sorting chips during sperm treatment in bovine IVEP increases the rate of reaching the blastocyst, embryo development, and quality and reduces the possibility of apoptosis in developing blastocysts. For this reason, it is also thought that the use of microfluidic sperm sorting devices during sperm treatment in bovine IVEP may be a new alternative in this field.

Post-mating diclofenac vs. carprofen treatment on serum progesterone levels and reproductive outcomes in Hungarian-Merino ewes during the non-breeding season.

The maternal recognition process is crucial for the establishment of healthy pregnancy. In this process, anti-luteolytic applications are one of the main reproductive strategies to manage the embryonic losses and maximize reproductive profitability in farm animals. The aim of this study was to investigate the efficacy of post-mating NSAID treatments on reproductive parameters (pregnancy rate, lambing rate, multiple birth rate, litter size) and serum progesterone levels in ewes stimulated with progesterone non-breeding season. For this purpose, two different experiments (diclofenac and carprofen) were conducted in the same ewe flock induced with short-term progestogen-based protocol in the non-breeding season for two consecutive years. In experiment 1 (n = 85), 42 ewes were injected with 2.5 mg/kg diclofenac on the 9th and 10th days post-mating, and the rest were not treated and served as control. In experiment 2 (n = 82), 40 ewes were injected with 1.4 mg/kg carprofen on the 9th days post-mating, and the rest were not treated as control. In both experiments, blood samples were collected from all ewes on days 9, 12 and 13 post-mating to measure serum progesterone levels. In both experiments, there were no differences both reproductive parameters and serum progesterone levels when compared to the control groups. It was concluded that post-mating diclofenac and carprofen treatments in the critical period have no significant effects on both reproductive parameters and serum progesterone levels in ewes in the non-breeding season.

The pharmacokinetics of letrozole and its effect on gonadotropins in anestrous ewes.

The aim of this study was to determine the pharmacokinetics of letrozole and its effect on FSH and LH concentrations after single (IV, IM, SC) and repeated IV doses in anestrous ewes. This study was conducted in experiments 1 and 2 by randomly dividing 24 healthy Akkaraman ewes in anestrus into two equal groups. In experiment 1, the pharmacokinetics of letrozole following single IV, IM, and SC administration at 1 mg/kg dose and its effect of a single IV dose on plasma FSH and LH concentration were determined. In experiment 2, the effect of repeated IV doses of letrozole on FSH and LH concentrations was established. Plasma concentration of letrozole was measured using high-performance liquid chromatography, and pharmacokinetic parameters were calculated by non-compartmental analysis. FSH and LH concentrations were quantified using ELISA. The elimination half-life (t1/2ʎz) for IV, IM, and SC routes were 9.94, 37.29, and 41.07 h, respectively. The IV route for letrozole had a total clearance of 0.11 L/h/kg and a volume of distribution at a steady state of 1.50 L/kg. The peak plasma concentration was 0.11 µg/mL for the IM route and 0.14 µg/mL for the SC routes. The bioavailability was 55.18% for the IM route and 75.34% for the SC route. Letrozole following single and repeated (every 24 h for 3 days) IV administrations at 1 mg/kg dose did not affect LH concentration in anestrous ewes but caused an increase in the FSH concentration. This increase in FSH concentration may create a potential for the use of letrozole in ovarian superstimulation protocols. Favorable pharmacokinetic properties (long t1/2ʎz and good bioavailability) of letrozole for IM and SC routes require further investigation before use in estrus induction or estrus synchronization protocols in sheep.

Effect of flunixin meglumine treatment during and after embryo transfer on the pregnancy rate in cattle.

This study aimed to determine the effect of flunixin meglumine treatment during and after the transfer of in vivo produced embryos to Angus (cows) and Holstein (cows and heifers) breeds of cattle on pregnancy rate. Holstein cows were used as donors in the study. A double dose of prostaglandin F2α was administered to the recipient animals for synchronization. Uterine flushing was performed in donors on day 7 after artificial insemination. A total of 295 transferable embryos were obtained. These embryos were transferred to Angus cows (n = 85), Holstein heifers (n = 80) and Holstein cows (n = 130). After the transfer, these animals were divided into three subgroups. The first subgroup (TI) was administered flunixin meglumine during embryo transfer, and the second subgroup (TII) was administered flunixin meglumine both during embryo transfer and on days 8 and 9 after the transfer. The third subgroup (TIII) was not administered anything and it was considered the control group. Pregnancy examination of the recipients was performed on days 30-35 after the transfer using real-time ultrasonography. The pregnancy rates after embryo transfer were found to be 43.52% in Angus cows, 42.5% in Holstein heifers, and 24.61% in Holstein cows (p < .05). When the animals were not classified according to breed, the pregnancy rates in subgroups TI, TII and TIII were found to be 29.29%, 45.10% and 29.79%, respectively (p < .05). In addition, the pregnancy rates were higher in TII and TIII subgroups of Angus cows and Holstein heifers compared to that of Holstein cows (p < .05). As a result, the pregnancy rates obtained after embryo transfer in Angus cows and Holstein heifers were found to be higher than that in Holstein cows. In addition, it was concluded that the administration of flunixin meglumine during and during/after embryo transfer has a positive effect on pregnancy rates in Angus cows and Holstein heifers.

Multiple ovulation and embryo transfer during the breeding season in Angora goats: A comparison of fresh and vitrified-thawed embryo transfer.

This study aimed to assess the superovulation response and pregnancy rates of fresh and vitrified-thawed embryos after transfer in Angora goats with comparing transfer at the beginning (BS) and end (ES) of the breeding season. Nine Angora goats were used as donors in both periods. Donor goats were synchronized and superovulated with the FSH and mated with five fertile bucks. At 156 hr following mating, embryos were collected surgically. Recipient Angora goats were divided into two groups at the beginning (fresh, n = 15; vitrified-thawed, n = 15) and end (fresh, n = 8; vitrified-thawed, n = 8) of the breeding season. Fresh or vitrified-thawed grade I embryos (early blastocyst/blastocyst) were transferred surgically to synchronized recipients. On the 30th, 60th and 90th day of transfer, goats were examined by ultrasonography. The number of corpora lutea (CL), total oocyte/embryo and transferable embryos obtained in BS was found to be statistically higher than ES. On the 30th day of transfer, pregnancy rates were 73.30% and 75.00% in the fresh transfer groups in both BS and ES periods; while, rates of 20.00% and 37.50% were found in the vitrified-thawed group, respectively. The embryo survival rates of fresh transfers were 55.55% and 31.25% at BS and ES, respectively. The number of CL, total oocyte/embryo and transferable embryos in the BS was higher than ES following superovulation. Also, fresh embryo transfer can be successfully carried out during the breeding season in Angora goats. Moreover, although pregnancies were obtained following the transfer of vitrified-thawed embryos, they did not sustain on the 60th and 90th days. So, further studies are needed for the vitrified-thawed embryos.

A meta-analysis of the effects of synchronization protocols applied to sheep in Turkey on pregnancy rates during breeding and non-breeding seasons.

This study aimed to determine common pregnancy rates and effect sizes with meta-analysis of studies investigating the effect of different synchronization protocols applied to sheep during breeding and non-breeding seasons on pregnancy rates. Common pregnancy rates were estimated by coalescing pregnancy rates of studies performed independently, and heterogeneity between the studies was investigated. The meta-analysis included 24 studies that determined pregnancy rates in 78 different groups consisting of 1934 sheep with five different synchronization protocols in Turkey between 2001 and 2020. Among the different synchronization methods, the P4+PMSG group (90.37%) during the breeding season and P4+PGF2α (69.77%) and P4 (68.75%) groups during the non-breeding season showed the highest pregnancy rate. Also, the effect size of P4+PMSG application during the breeding season was calculated as 0.934 (95% confidence interval: 0.901-0.967), and the effect size of P4+PGF2α application during the non-breeding season was calculated as 0.709 (95% confidence interval: 0.406-1.013). To conclude, the combination of P4+PMSG during the breeding season and progestogen and other hormone applications during the non-breeding season are the most effective methods for estrus synchronization and for achieving the desired pregnancy rates.

Evaluation of the relationship between serum paraoxonase-1 activity and superovulation response/embryo yield in Holstein cows.

In this study, the effect of serum paraoxonase-1 (PON-1) activity on superovulation response and embryo yield was evaluated. The study material comprised 50 Holstein cows aged 3-4 years on postpartum day 90-120 with a body condition score of 3-3.25. A progesterone-based estrus synchronization protocol was initially administered to the selected donors. For this purpose, progesterone source was inserted intravaginally (day 0) and gonadotropin-releasing hormone injection was performed (day 6). Seven days after the insertion of progesterone device, follicle-stimulating hormone injections (total dose of 500 µg in decreasing doses for 4 days) were administered for superovulation. On the morning of the ninth day, prostaglandin (PG) F2α was administered, and the progesterone device was removed from the vagina in the evening on the same day. Two days after PGF2α administration, fixed-time artificial insemination was performed in the morning and in the evening. On the day of artificial insemination, blood samples were taken from the donors to determine the serum PON-1 activity. Uterine flushing was performed seven days after insemination. The results revealed that the serum PON-1 activity (mean ± SD, 562.71 ± 140.23 U/l) of the cows that responded to superovulation (donors with total corpus luteum count of ≥3 in both ovaries) was higher than those (389.91 ± 80.51 U/l) that did not (P<0.05). On the day of insemination, a positive correlation was determined between serum PON-1 activity and the counts of total corpus luteum (r=0.398), total oocyte/embryo (r=0.468), transferable embryo (r=0.453), and Code I embryos (r=0.315, P<0.05). Unlike the Code I embryos, there was no significant correlation between serum PON-1 activity and the number of Code III embryos. Moreover, no significant difference in the number of Code III embryos between the two PON-1 groups was observed. However, embryo yield and quality were found to have increased with increased PON-1 activity. Therefore, it was concluded that serum PON-1 activity may be associated with superovulation response, embryo yield and quality in donor cows.

Effect of embryo quality and developmental stages on pregnancy rate during fresh embryo transfer in beef heifers.

The objective of this study was to evaluate the effect of embryo quality and developmental stages on pregnancy rate in beef heifer recipients. The present study used 168 Simmental breed cows as donors, and 618 beef cattle breed heifers as recipients. The quality and developmental stages of the collected embryos were evaluated according to the criteria specified by the International Embryo Technology Society. Accordingly, the embryos in the compact morula, early blastocyst, blastocyst, and expanded blastocyst stages that were of Code I (excellent) and Code II (good) quality levels were transferred as fresh embryos to the recipient heifers. Prior to the transfer, the recipients were synchronized using the Ovsynch protocol, and the embryos obtained were transferred to 618 beef heifers. Pregnancy examinations were performed on days 30 and 60. On day 30, the pregnancy rates with Code I and Code II embryos were determined as 44.15% and 32.58%, respectively. According to the developmental stages, the pregnancy rates with Code I quality compact morula, early blastocyst, blastocyst, and expanded blastocyst were determined as 44.64%, 45.67%, 45.83%, and 33.33%, respectively. The rates of pregnancy with Code II quality compact morula, early blastocyst, and blastocyst were determined as 32.03%, 32.14%, and 50.0%, respectively. In conclusion, the pregnancy rates with Code I quality embryos were found to be higher compared with Code II embryos (P < 0.05). It was also determined that the embryonic developmental stages had no effect on the pregnancy rate (P > 0.05).

Evaluation of the factors that affect the pregnancy rates during embryo transfer in beef heifers.

The aim of this study was to evaluate the effects of the transfer side, transfer location, cervix transfer score, type and diameter of corpus luteum (CL) during embryo transfer on pregnancy rates in beef heifers. Progesterone-based synchronization and superovulation protocol were applied to Simmental cows used as donors (n = 168). Uterine flushings were performed on day 7 following artificial insemination. Obtained Code I (excellent or good) and II (fair) quality embryos were transferred to recipient beef heifers (n = 561). During embryo transfer, side of transfer (right or left), transfer location (the cranial or middle third of uterine horn), cervix transfer score (easy, moderate or difficult) and type (CLa, CLb and CLc) and diameter of CL were determined. Pregnancy rates following the transfer of Code I and II embryos were 44.66% and 33.07%, respectively (p < .05). The rates of pregnancy after transfers to the right and left uterine horn were 37% and 42.2%, respectively (p > .05). The pregnancy rates were 41.2%, 34.9% and 30.3% for cervix transfer scores as easy, moderate and difficult, respectively (p > .05). Pregnancy rates after transfer to the cranial third and middle third were 41.06% and 29.67%, respectively (p < .05). According to types of CL, pregnancy rates were 31.7%, 40.4% and 45.3% for CLa, CLb and CLc, respectively (p < .05). Moreover, it was found that as the CL diameter increased, the pregnancy rates increased. As a result, it was concluded that there was no effect of side of transfer and cervix transfer score, but embryo quality, transfer location, type and diameter of CL had significant effects on the pregnancy rate during embryo transfer in beef heifers.

The effect of anti-müllerian hormone and progesterone concentrations on superovulation response and embryo yield in goats.

We aimed to evaluate the relationship of anti-Müllerian hormone (AMH) and progesterone concentrations with superovulation response in goats and to determine donors exhibiting better superovulation response by measuring AMH concentrations. For this, blood samples were collected from multiparous Angora goats (n = 24) for measuring the progesterone and AMH concentrations on the day the synchronization protocol was initiated (Day 0), on the day of the first FSH administration (Day 9), on the day the progesterone source was removed (Day 11), and on the day of uterine flushing. Descriptive statistics (mean, standard deviation, median, minimum value, maximum value, and percentile) were given for superovulation response and embryo yield. To compare the differences between the two groups, the Student's t-test was used. The relationship between two continuous variables was assessed by the Pearson Correlation Coefficient. The AMH cutoff values in superovulation responses were evaluated by ROC analysis on the day the synchronization protocol was initiated. A strong positive correlation was found between the AMH concentrations measured on the day the synchronization protocol was initiated (Day 0), on the day of the first FSH administration (Day 9), and on the day of removal of the progesterone source (Day 11) and the count of total corpus luteum (CL), total oocyte/embryo, transferable embryo, and Code I quality embryo (P < 0.05). Furthermore, AMH concentration increased on the day the synchronization protocol was initiated, the donor's superovulation response increased as well. The cutoff value was 4.74 ng/ml, as assessed by the ROC curve analysis conducted for selecting donors exhibiting better superovulation responses. The sensitivity and specificity of the selected cutoff value were found to be quite high (P < 0.01). However, a positive correlation was noted between the progesterone concentrations measured on the day of uterine flushing and total CL count, total oocyte/embryo count, transferable embryo count, and Code I quality embryo count (P < 0.01). In conclusion, it was determined that an increase in AMH concentrations in goats led to an increase in the total CL count, embryo count, and embryo quality and that AMH measurement could be used to identify donors that responded better to superovulation. Additionally, a positive correlation was found between the progesterone concentration measured on the day of uterine flushing and the total CL count, transferable embryo count, and embryo quality.

Aglepristone and cloprostenol combination in the termination of late-term pregnancy in queens.

OBJECTIVES: Termination rates for the highly recommended aglepristone (AGL) treatment are low in late-term pregnancy in queens. We studied the effects of an AGL and cloprostenol (CLO) combination in the termination of late-term pregnancy. METHODS: Pregnant queens were assigned to two groups. Queens in the AGL group (n = 10) received AGL 10 mg/kg, twice, 24 h apart. Queens in the AGL-CLO group (n = 9) were additionally injected with a single dose of CLO (5 µg/kg) 24 h after the second dose of AGL. Progesterone, 17beta(ß)-oestradiol, cortisol, oxytocin and prostaglandin F2alpha (PGF2α) metabolite were measured in sera obtained at days 0, 1 and 2, and on the day of abortion. RESULTS: Average gestational age in both groups was similar (AGL 38.61 ± 0.91 days vs AGL-CLO 39.39 ± 1.35 days; P >0.05). Termination rates were 80% and 100% in the AGL and AGL-CLO groups, respectively (P <0.05). Fetal expulsion time was significantly longer (P <0.001) in the AGL group (96.9 ± 6 h) compared with the AGL-CLO group (69.8 ± 3.3 h). Duration of abortion was 19.8 ± 2.6 h and 12.6 ± 1.4 h in the AGL and AGL-CLO groups, respectively (P <0.05). Both treatments were well tolerated. Significantly (P <0.05) lower serum progesterone concentrations were observed in both groups at the day of abortion and concentrations in the AGL-CLO group (4.19 ± 0.80 ng/ml) were lower than in the AGL group (9.89 ± 2.21 ng/ml; P <0.05). CONCLUSIONS AND RELEVANCE: AGL and CLO combination increases pregnancy termination rate in late-term pregnant queens. In addition, CLO contributes to a decrease in luteal function in AGL-treated late-term pregnant queens.

Determination of the relationship between serum anti-Müllerian hormone level and superovulatory response in Simmental cows.

The most significant focal points of the embryo transfer technology are as follows: the selection of donors, the response of the selected donor to the superovulation protocol and the obtained number of the transferable embryos. For this purpose, it is suggested that donor selection can be done by anti-Müllerian hormone (AMH) levels, and embryo production is evaluated. AMH is secreted by the granulosa cells of primordial, pre-antral and antral follicles below 4 mm in the ovary, independent of FSH. Therefore, the aim of this study was to investigate the relationship between serum AMH levels and the number of corpus luteum (CL), total embryos and transferable embryos that were shaped after a uniform superovulation protocol. For this reason, 48 Simmental cows, which were located at General Directory of Agricultural Enterprises (region, province, etc. instead of the general directorate), were used as donors for the embryo transfer. Blood samples were taken at random, regardless of the stage of animal's sexual cycle. AMH levels were measured by enzyme-linked fluorescent assay (ELFA) method of the miniVIDAS® (bioMérieux SA) using AMH Bovine Test Kit. According to the statistical analyses of the obtained data, AMH levels were positively correlated with CL and total embryos (p < .05). No significant correlations between AMH and transferable embryos were approved (p > .05). It was also determined that each 200 pg/ml increase in serum AMH level resulted in one increase in CL number. Overall, considering the positive correlation between AMH level and the obtained number of CL and total embryos after a superovulation treatment, it was concluded that measuring blood AMH level prior to any further costly implementation may be an effective method in donor selection.

Immunohistochemical and qPCR determination of the expression and serum level of anti-Müllerian hormone in pre-pubertal, intact and ovarian remnant syndrome detected bitches.

The aim of this study was to determine the serum concentrations, ovarian presence and expression of anti-Müllerian hormone (AMH) in pre-pubertal, bitches with signs of ovarian remnant syndrome (ORS) and intact bitches. In addition, we aimed to verify the suitability of serum AMH concentrations for diagnostic purposes in sterilized bitches and/or in suspected cases of ORS in the field of veterinary medicine. For this purpose, 36 healthy female dogs divided into six groups: proestrus, oestrus, dioestrus, anoestrus, pre-pubertal and ORS. Serum AMH concentrations were determined by electrochemiluminescence immunoassay, and ovarian presence and distribution of AMH was confirmed by immunohistochemical and qPCR techniques. According to the results of qPCR, while the expression values of AMH were at the highest concentrations in the proestrus and oestrus, there was a statistically significant decrease in these values at the later stages of the cycle (p < 0.05). According to hormone analysis, the serum AMH values of the ORS group had decreased significantly compared with the proestrus and oestrus (p < 0.05). Although serum AMH levels of ORS group were increased compared with anestrus and pre-pubertal groups, this increase was statistically non-significant (p > 0.05). Immunohistochemically, AMH expression was first observed in the granulosa cells of primordial follicles in folliculogenesis. Expression values were the highest in the proestrous and oestrus groups, but values from bitches in later stages of the cycle were statistically significant decrease in comparison with these groups (p < 0.05). As a result, AMH concentration and expression were found to be higher in proestrus and oestrus than in other periods (p < 0.05). In addition, the measurable level of AMH concentration in bitches with ORS is an indication that it can be used in the diagnosis of ORS.

Expression of iNOS, COX-2 and VEGF in canine mammary tumours and non-neoplastic mammary glands: Association with clinicopathological features and tumour grade.

The aim of the present study was to investigate the relationship between the expression of iNOS, COX-2 and VEGF mRNA levels and malignancy degree in canine malignant mammary tumours. Thirty-five bitches presented with the complaint of mammary masses, aged 6-10 years and representing different breeds, were used. The expressions of iNOS, COX-2 and VEGF mRNA levels were significantly higher in both benign and malignant tumours than in the adjacent nonneoplastic mammary glands (P < 0.05). The iNOS, COX-2 and VEGF mRNA expression levels of grade 2 tumours were higher than those of grade 1 tumours; however, the highest expression levels were detected in grade 3 tumours. Thus, increased iNOS, COX-2 and VEGF gene mRNA levels were found to be related with the histological grade of malignancy in dogs with mammary tumours.

Conflicts in benefits from sustainable natural resource management: two diverse examples from Turkey.

Participatory approaches to natural resource management and development are widely accepted as effective instruments for achieving sustainable forest management (SFM) particularly in the developing countries. However, local people live within and adjacent to the forest resources and are dependent on the forest in terms of their livelihoods may prevent turning some decisions, intended as a component of sustainable forest management, into action. This situation arises from the lack of involvement by local stakeholders, a condition that is generally accepted as one of the most important instruments of sustainable forest management. Consequently forest and other natural resources have not been effectively protected from negative behaviours of local populations. In this study difficulties that have been faced in acquiring local participation and the importance of local participation for sustainable forest management are discussed using two case studies from Turkey. At acquiring of local participation is considered to important of local perceptions. If perceptions are negative, participation will not obtain. Thus, the study has focused on local perceptions. Field survey was carried out to collect necessary information for each case study. We conclude that decisions that will restrict the natural resource benefits for the local public, will lead to negative local perceptions of the project and lead to adverse behavior and negatively affect sustainable forest management efforts.

Negative impact of rural settlements on natural resources in the protected areas: Kovada Lake National Park, Turkey.

In this study negative human impacts on natural resource values of Kovada lake National park (KLNP) have been discussed in accordance with actual data and evaluations obtained from field surveys. The method used in this study is based on questionnaire, interviews and direct observations conducted in rural settlements within the boundary of the national park. According to the results of this study; Kovada Lake and its environs have not been protected from negative human impacts until now. Therefore, within this study, the proposals for the solutions of problems due to protection and utilization in the national park have been developed.