Genetic analysis of Saker Falcon (Falco cherrug) subspecies

Two subspecies of Saker Falcon are commonly accepted - Western (Falco cherrug cherrug) and Eastern (Falco cherrug milvipes), which are differentiated by their distribution range and phenotype. In Bulgaria, Western Saker Falcons are breeding ex situ in the Wildlife Rehabilitation and Breeding Centre, part of Green Balkans - Stara Zagora NGO, with the aim of restoring the nesting population of the species in the country and both Western and Eastern - in the Breeding Centre for Birds of Prey in Burgas for the purpose of sale for the needs of falconry in the country and abroad. In 2021, a total of 115 birds from the two breeding centres were sampled. The samples were analysed in Bielefeld University (Germany) at nine microsatellite loci. Structure analyses were performed to establish the optimal explanatory number of groups. We compared the putative genetic groups with the known/expected origin of falcons. A separation in two groups best explained the allelic variation between samples. Out of 68 Saker Falcons with putatively Eastern origin, 66 were ascribed to genetic group 2 and two falcons had unclear, mixed or hybrid genetic fingerprints. Out of 42 Sakers with putatively Western origin, 33 were ascribed to genetic group 1, seven to genetic group 2 and two individuals appeared to have a mixed signature of genetic groups 1 and 2 with dominating alleles of group 2. Five known hybrids were scored as mixed signature with dominating genetic cluster 2. This suggests that the two (Eastern and Western) populations of Saker Falcon origin suggested by the subspecies' definitions are also adequate to be considered in breeding programmes. Genetic cluster 1 might represent the ancestral alleles shared with other falcons, while specific novel alleles allow the discrimination of secured Eastern Sakers (group 2), while these populations may be occasionally invaded by individuals from the west

Effect of Ovarian Status on Reproductive Performance in Dairy Heifers Inseminated with Sexed Semen

Background: The intensive reproductive management in the dairy farms requires inclusion of a large group of replacement heifers in the breeding program for a shorter period. In this aspect, a creation of effective estrus synchronization protocols with timed artificial insemination (TAI) by sexed semen and optimization of the current ones have a crucial role for obtaining high pregnancy rate. These protocols are beneficial, because they led to reduced interval to first AI, lack of need for estrus detection, and allow obtaining a large group of female calves for on time. Because of limited fertilizing potential of sexed spermatozoa this type of semen is applied mainly for heifers, as fertility is higher compared to lactating cows. The main objective of the present study was to investigate the effect of ovarian status on the reproductive performance in dairy heifers subjected to estrus synchronization and timed artificial insemination with sexed semen. Materials, Methods & Results: Forty-eight Holstein healthy heifers separated in 2 groups were subjected to PGF2α-GnRH pre-treatment and Ovsynch or PRID-5-day estrus synchronization protocol and timed artificial insemination (TAI) with sex-sorted semen, staring 6 days after end of the hormonal pre-treatment. The ovarian status (presence of follicles with or not a corpus luteum) of the heifers at the begin of the treatment, on day of TAI and pregnancy rate in different groups were determined and compared. Additionally, the ovarian status at the begin of the treatment, ovarian status and size of preovulatory follicle (PF) on day of TAI and total values for both groups according to reproductive performance (pregnant or non-pregnant) were also analyzed. On day of TAI the animals with PF and a lack of corpus luteum (CL) in both groups were more that those with PF and CL (39.3% and 30% vs. 60.7 % and 70%), with significant (P < 0.05) difference in PRID-5-day group. The pregnancy rate tended to be higher in PRID-5 day than Ovsynch treatment (65% vs. 35.7%). A higher percentage (100% and 67.9%) of the pregnant animals in both treatments had not CL on day of TAI, and the size of the PF (1.58 ± 0.12 cm and 1.64 ± 0.13 cm) was increased (P < 0.05). Similar effects of the ovarian status on reproductive performance were obtained after a comparison of the total values between pregnant and non-pregnant animals. The percentage of heifers with observed PF without CL on day of TAI was significantly greater (P < 0.05) in pregnant compared to non-pregnant group (91.3% vs. 40%). The opposite dependence was determined for the parameter presence of follicles and corpus luteum (8.7% vs. 60%; P < 0.05).  Furthermore, the size of the PF measured immediately before TAI was increased in animals became pregnant (1.60 ± 0.12 cm vs. 1.34 ± 0.17 cm; P < 0.05). Discussion: The analysis of the obtained results showed that the ovarian status on day of TAI affects the reproductive performance in dairy heifers subjected to estrus synchronization and timed artificial insemination with sexed semen. Hormonal pre-treatment with onset of PRID-5-day protocol 6 days later and TAI with sex-sorted semen ensure acceptable pregnancy rate. The greater preovulatory follicle and a lack of corpus luteum before insemination provide significantly (P < 0.05) more pregnant animals, compared to the cases when CL is presented. Ultrasound determination of the ovarian function before insemination can be used in selection of heifers for TAI with sex-sorted semen.                   Keywords: heifers; estrus synchronization; sexed semen, pregnancy

DNA Methylation Level of Gene SIRT1 in Ram Spermatozoa and Relationship with Fertilizing Ability According to Breed and Age

Background: Effect of the epigenetic factors on the male fertility is well proofed. Sperm acts as a carrier of genetic material, and its DNA methylome can affect maternal pregnancy rate and offspring phenotype. However, the research on the DNA methylation in the spermatozoids of livestock males, in particular rams, is still limited. To best of our knowledge the data about as a global as well as gene specific DNA methylation in ram spermatozoa from different breeds and ages are missed in the scientific literature. The present study was designed to analyze the relationship between methylation levels of the important for spermatogenesis gene SIRT1 in spermatozoa and fertilizing ability of sperm in rams from different breeds and ages. Materials, Methods & Results: The ejaculates of 16 rams from Lacaune, East Friesian and Assaf breeds at age between 18 to 96 months were evaluated. The kinematic parameters of 2 semen samples from each animal were estimated by CASA. The separated spermatozoa were used for DNA extraction followed by bisulfite conversion. The DNA methylation of SIRT1 was detected through quantitative methylation-specific PCR using 2 sets of primers designed specifically for bisulfite-converted DNA sequences to attach methylated and unmethylated sites. The breed and age effect on the gene SIRT1 methylation by ANOVA was estimated. Experimental females included 393 clinically healthy milk ewes (Lacaune, n = 131; East Friesian sheep, n = 100 and Assaf, n = 162) in breeding season. Reproductive performances (conception rate at lambing, lambing percentage and fecundity) of ewes, inseminated by sperm of the investigated rams, were statistically processed. ANOVA showed that the animal breed influences significantly on the level of DNA methylation of gene SIRT1 in ram spermatozoa (P = 0.002) An average value of DNA methylation of SIRT1 in ram sperm from Lacaune breed was significantly higher than in Assaf and East Friesian (81.21 ± 15.1% vs 36.7 ± 14.2% and 38.3 ± 18.6 respectively, P < 0.01). The highest percent of SIRT1 methylation was observed in old animals compared to the young and middle-age. Moderate and strong correlations (r from 0.44 to 0.71, P < 0.05) between the methylation level of the SIRT1 gene in rams' sperm and reproductive parameters of inseminated ewes in all breeds were established. Discussion: Our data are the first message about the effect of breed on the specificity of DNA methylation of gene SIRT1 in ram spermatozoa. These results demonstrated an existence of the sheep breeds with high and low level of DNA methylation of gene SIRT1 in ram sperm. Although the effect of age on the methylation level in sperm is still discussable, our results showed a moderate correlation between age and methylation level of SIRT1 in spermatozoa of rams. Taking into account that DNA methylation in sperm is stabilized with puberty onset and is a heritable epigenetic modification, it can be a promising marker of sperm quality in animal breeding. In all investigated breeds the rams with relatively high level of DNA methylation of gene SIRT1 in spermatozoa (50-68%) demonstrated a high conception rate at lambing (> 70%). In conclusion, the DNA methylation level of the SIRT1 gene in ram spermatozoa is determined by both the breed and the age of the animals and correlates with fertilizing ability of sperm. Keywords: SIRT1 methylation, ram spermatozoa, Lacuane, East Friesian, Assaf breeds

Comparison of blood biochemical parameters of four species of vultures

Vultures play a very important role in ecosystems by feeding on dead animals and preventing the spread of pathogens. In the mid-20th century in Bulgaria, all species of vultures experienced a rapid population decline and conservation measures include captive breeding and release via adaptation aviaries. Knowledge of the baseline blood biochemical parameters is crucial for the care, rehabilitation and prior to the release of endangered birds of prey. Plasma levels provide valuable information for the evaluation of the physical condition of animals.Between 2020 and 2022, we took blood samples from captive Bearded, Griffon, Cinereous and Egyptian Vultures in Bulgaria (n = 118). We determined the values of 18 parameters - alanine transaminase, albumin, alkaline phosphatase, amylase, aspartate transaminase, calcium, chloride, cholesterol, creatine kinase, creatinine, glucose, lactate dehydrogenase, magnesium, phosphorus, total bilirubin, total protein, triglycerides and uric acid. This research determined the mean blood biochemical indices for aviary Bearded, Griffon, Cinereous and Egyptian Vultures in Bulgaria and compared the values amongst the four vulture species, to serve in determining clinical pathology and nutrition for scavenger birds of different species, age groups and genders in the country.The results of this study suggested that there are significant differences between many of the indicators of the four vulture species. There are fewer differences in the indicators of different ages of birds of a given species and almost no differences are found between the two sexes of a species. These values could be used by scientists, veterinary pathologists, wildlife rehabilitation centres and other researchers. Furthermore, the use of such parameters in assessing population health may enable conservationists to further research environmental conditions affecting the vultures’ reproduction and survival

Genetic analysis of Saker Falcon (Falco cherrug) subspecies

Petrov R, Yarkov D, Chakarov N. Genetic analysis of Saker Falcon (Falco cherrug) subspecies. Biodiversity Data Journal . 2024;12: e116889.Two subspecies of Saker Falcon are commonly accepted - Western (Falco cherrug cherrug) and Eastern (Falco cherrug milvipes), which are differentiated by their distribution range and phenotype. In Bulgaria, Western Saker Falcons are breeding ex situ in the Wildlife Rehabilitation and Breeding Centre, part of Green Balkans - Stara Zagora NGO, with the aim of restoring the nesting population of the species in the country and both Western and Eastern - in the Breeding Centre for Birds of Prey in Burgas for the purpose of sale for the needs of falconry in the country and abroad. In 2021, a total of 115 birds from the two breeding centres were sampled. The samples were analysed in Bielefeld University (Germany) at nine microsatellite loci. Structure analyses were performed to establish the optimal explanatory number of groups. We compared the putative genetic groups with the known/expected origin of falcons. A separation in two groups best explained the allelic variation between samples. Out of 68 Saker Falcons with putatively Eastern origin, 66 were ascribed to genetic group 2 and two falcons had unclear, mixed or hybrid genetic fingerprints. Out of 42 Sakers with putatively Western origin, 33 were ascribed to genetic group 1, seven to genetic group 2 and two individuals appeared to have a mixed signature of genetic groups 1 and 2 with dominating alleles of group 2. Five known hybrids were scored as mixed signature with dominating genetic cluster 2. This suggests that the two (Eastern and Western) populations of Saker Falcon origin suggested by the subspecies' definitions are also adequate to be considered in breeding programmes. Genetic cluster 1 might represent the ancestral alleles shared with other falcons, while specific novel alleles allow the discrimination of secured Eastern Sakers (group 2), while these populations may be occasionally invaded by individuals from the west

The just transition of the European Green Deal and the development of the regions with intensive coal mining (example of Marishki Basin – Bulgaria)

The just energy transition is an opportunity to drive a very important process of transformation of the traditional linear, waste holding economy based on fossil fuels and polluting transport to a new type of economy, driven by the circularity bio-, RES economics paradigm and environmentally responsible transport. The purpose of this study is to contribute to the identification of the direction, factors and mechanisms of the energy transition in the Marishki Basin – Bulgaria, as well as to formulate proposals related to the development of territorial plans for a just transition and the integrated development plans of the municipalities. The methods that have been applied to achieve the purpose of the research are qualitative – desk research (search for general information about the object and the subject of the research – offline and online) and an in-depth interview with leading experts (regarding the process of transition and transformation of the Maritsa East complex). In addition to subjective expert assessments, objective statistical data for the region and for the Maritsa East complex were used for the needs of the research. The present work summarizes the views of the leading experts and makes suggestions regarding the future economic development of the region concerned and its energy transition. The Marishki Basin is a region within which it is necessary to develop and implement a system of projects and measures to be set out in the integrated development plans of the municipalities concerned and to be part of the territorial plans for a just transition. The leading sectors are to bet agri-energ biotechnology, aquaponics, “hydrogen valleys”, digital industries, robotics, urban agriculture, tourism and other activities that would create an innovative economic organism in the region

Price determinants and interactions specifics in beef production in Bulgaria

A major component of the supply function - product price - is dissuasive for the Bulgarian beef producers and the authors set the objective to examine the price determinants considering price determination (market) and price manifestation (transaction) as two interconnected concepts. The trend of prices and price ratio in Bulgarian beef production are studied as well as the leading factors determining the level and dynamics of procurement prices for the period 2008-2016, using economic-statistical analytical methods and models: the assessment of the price and income elasticity by applying the model by Workman, King, Hooper; cointegration model is applied for determining correlation between the beef wholesale and retail prices on one hand and on another hand the correlation between procurement and retail prices. The descriptive decomposition of the price determination and price manifestation is conducted. Conclusion about the main price features of Bulgarian beef market are presented and their key factors, as well as proposals for solving the adverse effects

Effect of Ovarian Status on Reproductive Performance in Dairy Heifers Inseminated with Sexed Semen

Background: The intensive reproductive management in the dairy farms requires inclusion of a large group of replacement heifers in the breeding program for a shorter period. In this aspect, a creation of effective estrus synchronization protocols with timed artificial insemination (TAI) by sexed semen and optimization of the current ones have a crucial role for obtaining high pregnancy rate. These protocols are beneficial, because they led to reduced interval to first AI, lack of need for estrus detection, and allow obtaining a large group of female calves for on time. Because of limited fertilizing potential of sexed spermatozoa this type of semen is applied mainly for heifers, as fertility is higher compared to lactating cows. The main objective of the present study was to investigate the effect of ovarian status on the reproductive performance in dairy heifers subjected to estrus synchronization and timed artificial insemination with sexed semen. Materials, Methods & Results: Forty-eight Holstein healthy heifers separated in 2 groups were subjected to PGF2α-GnRH pre-treatment and Ovsynch or PRID-5-day estrus synchronization protocol and timed artificial insemination (TAI) with sex-sorted semen, staring 6 days after end of the hormonal pre-treatment. The ovarian status (presence of follicles with or not a corpus luteum) of the heifers at the begin of the treatment, on day of TAI and pregnancy rate in different groups were determined and compared. Additionally, the ovarian status at the begin of the treatment, ovarian status and size of preovulatory follicle (PF) on day of TAI and total values for both groups according to reproductive performance (pregnant or non-pregnant) were also analyzed. On day of TAI the animals with PF and a lack of corpus luteum (CL) in both groups were more that those with PF and CL (39.3% and 30% vs. 60.7 % and 70%), with significant (P < 0.05) difference in PRID-5-day group. The pregnancy rate tended to be higher in PRID-5 day than Ovsynch treatment (65% vs. 35.7%). A higher percentage (100% and 67.9%) of the pregnant animals in both treatments had not CL on day of TAI, and the size of the PF (1.58 ± 0.12 cm and 1.64 ± 0.13 cm) was increased (P < 0.05). Similar effects of the ovarian status on reproductive performance were obtained after a comparison of the total values between pregnant and non-pregnant animals. The percentage of heifers with observed PF without CL on day of TAI was significantly greater (P < 0.05) in pregnant compared to non-pregnant group (91.3% vs. 40%). The opposite dependence was determined for the parameter presence of follicles and corpus luteum (8.7% vs. 60%; P < 0.05).  Furthermore, the size of the PF measured immediately before TAI was increased in animals became pregnant (1.60 ± 0.12 cm vs. 1.34 ± 0.17 cm; P < 0.05). Discussion: The analysis of the obtained results showed that the ovarian status on day of TAI affects the reproductive performance in dairy heifers subjected to estrus synchronization and timed artificial insemination with sexed semen. Hormonal pre-treatment with onset of PRID-5-day protocol 6 days later and TAI with sex-sorted semen ensure acceptable pregnancy rate. The greater preovulatory follicle and a lack of corpus luteum before insemination provide significantly (P < 0.05) more pregnant animals, compared to the cases when CL is presented. Ultrasound determination of the ovarian function before insemination can be used in selection of heifers for TAI with sex-sorted semen.                   Keywords: heifers; estrus synchronization; sexed semen, pregnancy

Basic blood biochemical parameters of wild common ravens (Corvus corax)

Baseline haematological and biochemical blood parameters in healthy wild birds are key to managing wild populations and to saving critically ill individuals. This knowledge is crucial for the care, rehabilitation and the release of birds after treatment in wildlife rescue centres. Plasma levels provide valuable information for the evaluation of the physical condition of animals. The objective of this study was to obtain reference values of some basic biochemical blood parameters of wild common ravens (Corvus corax). Between 2020 and 2023, we took blood samples from the wild population of common ravens in Bulgaria (n = 36). We determined the values of 18 parameters - alanine transaminase (ALT, U/I), albumin (g/l), alkaline phosphatase (ALP, U/I), amylase (U/I), aspartate transaminase (AST, U/I), calcium (mmol/l), chloride (mmol/l), cholesterol (mmol/l), creatine kinase (CK, U/I), creatinine (μmol/l), blood glucose (mmol/l), lactate dehydrogenase (LDH, U/I), magnesium (mmol/l), phosphorus (mmol/l), total bilirubin (μmol/l), total protein (g/l), triglycerides (TG, mmol/l) and uric acid (μmol/l). We made a comparative analysis including the regions in which the groups were sampled and the time of year. Most of the presented results were comparable to published values of other species from the Corvidae family and some were higher (ALP, amylase, AST, CK, total protein and uric acid levels). Most of these could be explained by the capture- and handling stress. This is the first report in official literary sources presenting some basic biochemical blood parameters of healthy wild common ravens in Bulgaria. The results may be of use to scientists, veterinarians and other researchers in rescue and rehabilitation centres and they can provide the basis for further studies with regards to animal welfare and health assessment of the species

Comparison of blood biochemical parameters of four species of vultures

Vultures play a very important role in ecosystems by feeding on dead animals and preventing the spread of pathogens. In the mid-20th century in Bulgaria, all species of vultures experienced a rapid population decline and conservation measures include captive breeding and release via adaptation aviaries. Knowledge of the baseline blood biochemical parameters is crucial for the care, rehabilitation and prior to the release of endangered birds of prey. Plasma levels provide valuable information for the evaluation of the physical condition of animals.Between 2020 and 2022, we took blood samples from captive Bearded, Griffon, Cinereous and Egyptian Vultures in Bulgaria (n = 118). We determined the values of 18 parameters - alanine transaminase, albumin, alkaline phosphatase, amylase, aspartate transaminase, calcium, chloride, cholesterol, creatine kinase, creatinine, glucose, lactate dehydrogenase, magnesium, phosphorus, total bilirubin, total protein, triglycerides and uric acid. This research determined the mean blood biochemical indices for aviary Bearded, Griffon, Cinereous and Egyptian Vultures in Bulgaria and compared the values amongst the four vulture species, to serve in determining clinical pathology and nutrition for scavenger birds of different species, age groups and genders in the country.The results of this study suggested that there are significant differences between many of the indicators of the four vulture species. There are fewer differences in the indicators of different ages of birds of a given species and almost no differences are found between the two sexes of a species. These values could be used by scientists, veterinary pathologists, wildlife rehabilitation centres and other researchers. Furthermore, the use of such parameters in assessing population health may enable conservationists to further research environmental conditions affecting the vultures' reproduction and survival