To edit the duck genome by HDR-directed integration of the EGFP gene into the duck host genome in combination with SMGT using CRISPR/Cas9. Methods. HDR-mediated gene of green fluorescent protein (EGFP) was crried out by the combined action of four plasmids. The pX330 contained the Cas9 gene. Two plasmids contained sgRNA genes: pBR322-sgRNA1 and pBR322-sgRNA2. The pBR322-HDR-EGFP plasmid was constructed to contain the DNA vector with left homologous sequence part(LHP), the EGFP gene coding sequences and the right homologous sequence part(RHP). The DNA sequence data for designing the HDR-EGFPinsert and sgRNA 1 and sgRNA 2 were taken from the genome DNA sequence of Anas platyrhynchos Spindlin 1 (SPIN1) gene. Twenty four ducks (13 males and 11 females) of the Shaoxing breed were used for this experiment. The sperm transfection was performed using Lipofectamine 2000. Results. Thirty one ducks were obtained, 19 of which carried the EGFP gene. F2 analysis revealed that 16 ducks (F1) (14 females and 2 males) transmitted the transgene DNA to their offsprings. Thus 27.6 % (56/203) of F2 descendants were positive for the transgene DNA construct. Conclusions. Exogenous DNA was successfully inserted into the duck genome.

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The paper studies interspecies physiological and genetic differences between the white-collared flycatcher and the pied flycatcher of the genus Ficedula. The fact that the flycatchers are capable of interspecies hybridization is one more reason for particular interest to these species. Using our own-developed method of taking venous blood from the eye’s sinus, we took blood samples from birds in the protected area of Homilshanski Forests, Kharkiv, Ukraine, to study their leukogram patterns. The bird feathers were also collected for genetic analysis -- to identify interspecies differences with application of the ISSR technique. It was revealed that the percentage of heterophiles in the nestlings of the pied flycatcher was lower than in the nestlings of the white-collared flycatcher. The micronucleus test did not reveal any significant difference in the interspecies groups. The spectra of amplification products obtained with the primer (AGC)6 G showed that the white-collared flycatchers had a more heterogeneous structure. The study of the leukogram, micronucleus test, and the ISSR analysis can be especially effective in the study of intra-species genetic differentiation.

The purpose of this study was to monitor the egg productivity of the Shaoxing breed ducks from the age of 24 (beginning of egg laying) and 75 (end of egg laying) weeks. According to the results of a study of over 2385 eggs, a significant difference was found between the weight indicators (57.93 g and 70.81 g; p˂0.01), the shape index (73.71% and 75.35%, p˂0.01), the strength of the shell (4.92kg and 4.28kg; p˂0.01), the thickness of the shell of the egg (0.48mm and 0.45mm; p˂0.01) in ducks at the age of 24 and 75 weeks. It also shows changes in the weight and shape of the egg with the age of the bird. The necessity of further studying the genetic diversity of birds, which causes the separate variability of indices of individual ducks, is substantiated.

The aim of the study was to determine the effects of genotype and sex on carcass composition and selected meat quality parameters of Dworka and Pekin ducks after two reproductive seasons. The research material consisted of 24 carcasses of Dworka ducks (breeding strain D11) and 24 carcasses of Pekin ducks from the herd of genetic resources (French Pekin, strain P-9). After cooling the carcasses (18 h, 2 °C), the pH values and electrical conductivity of the pectoral and leg muscles were determined, and then the carcass was dissected using a simplified method. After dissection, the pectoral and leg muscles were sampled for quality characteristics assessment. The Dworka ducks from breeding strain D11 compared to Pekin duck from conservative strain P9 were characterized by significantly (p < 0.05) higher carcass weight, protein and salt content, thermal drip, yellowness, thickness of perymisium and endomysium and lower water content of the pectoral muscle. Dworka ducks were also characterized by higher protein, salt and collagen content and higher electrical conductivity (EC24) of leg muscles than Pekin ducks. Regardless of genotype, male ducks had a higher gutted carcass weight with neck, salt content, muscle fiber cross-sectional area, fiber perimeter and diameters of pectoral muscle, and also higher protein and collagen, and lower fat content, pH24 and electrical conductivity of leg muscles. The genotype by sex interaction was significant (p < 0.05) for water, protein, fat content, perimisium thickness, cohesiveness, springiness of the pectoral major muscle, and for water content and protein of the leg muscles. The results obtained in this study demonstrate the effects of genotype and sex on the nutritional value and some technological parameters of duck meat. The studied ducks after two reproductive seasons satisfactorily meet the requirements of duck meat for consumers and duck meat processing plants.

The main biological functions of eggs include its ability to create optimal conditions for embryos, which, accordingly, contributes to the preservation and reproduction of the species. It is recommended for incubation to take eggs from physiologically healthy, mature birds, because the quality of the incubation eggs depends on the yield of the young, the vitality and productivity of the poultry. A prerequisite for a successful incubation is the assessment of eggs for a variety of morphological characteristics, but this can not be done without taking into account the biological features of incubation eggs associated with breed, crossbreed and bird age. It is known that with the age of the bird, the morphological parameters of the egg and its incubation capacity are changing. In particular, the weight and shape of the egg vary during the period of increasing the bird's egg-laying. The chicken egg has been extensively studied in the world and national scientific literature, its quality and composition, but over the past decades eggs of various types of poultry have been entered into the field of research: turkeys, guinea fowl, quails, ostriches and ducks. The Shaoxing Species (Shaoxing) belongs to the main Chinese egg rocks. Ducks of this breed are characterized by high performance, such as early maturity (130–140 days), long-term peak period of laying eggs (8–10 months) and good breeding (290–310 eggs for 500 days). Such indicators are some of the best for egg bird. That is why the purpose of the work was to determine the effect of the physico-morphological indices of the egg, the age of the bird and the color of the shell on the incubation properties of the eggs of the ducks of the Shaoxing breed. Three comparative analyzes of morphological parameters and their influence on the incubation capacity of eggs were selected from three experimental groups of ducks of the Shaoxing of different ages. Group number 1 carried eggs from females age 41 week, group number 2–63 weeks, and females group number 3 had an age of 71 weeks. The study of changes in the physico-morphological parameters of eggs and incubation ability was investigated within three months. A total of 360 eggs were analyzed. As a result of the experiment, the mass of experimental eggs ranged from 65.83 g (group 1) to 71.13 g (group 3). Between these indicators, a significant difference was found (p ˂ 0,01). Comparison of the studied physico-morphological characteristics of the groups number 1, number 2 and number 3 showed that there is a significant difference between the indices of longitudinal and transverse diameters in the eggs of the studied groups (p ˂ 0,01). Investigation of the thickness of the egg shell has shown that, according to the results, this ostentatious decreases with age (p ˂ 0,05). The obtained data coincide with the results of other researchers. After analyzing the data of the egg shape index, it was found that in the birds of the three studied groups, the average figures were in line with the norm. However, a significant difference was found between the characteristics of groups 1 and 3 (p ˂ 0.1). After analyzing the results of the incubation of eggs from the experimental groups of ducks, we found that the highest fertility of the eggs of group 3 was 92.5%, compared with the group 2–89.16% and 1–87.5%. According to the index of egg output and ducklings, the leader, the group was 3 (75.0%). The results obtained fully correspond to the data obtained from these physical and morphological studies of these eggs. The worst indices of both egg and duckin removal were in group 1. It should also be noted that this group had the largest number of choked (6.67%) and unfertilized eggs (15 pcs.), But these parameters decreased with the age of bird. Consequently, we have established that with the age of birds there is a change in the physical and morphological parameters of eggs (increase in weight, decrease in the thickness of the shell and increase in the index of suitability of eggs for incubation). The general tendency to reduce the embryonic viability of the duckies associated with the mass (group 1) and the form index (group 2) has also shown that eggs of medium size that are not below the standards for the breed standard by mass and index should be selected for incubation forms (group 3). There was a correlation between the incidence of egg incubation and the index of form in group 3, which had a direct impact on incubation and egg output.