Periods Of Postnatal Ontogenesis Research Articles

Neuropeptide Y is involved in the regulation of the frequency and strength of rat atrium spontaneous contraction

BACKGROUND: The relevance of the problem increases due to the established cardioprotective effect of neuropeptide Y in pathological conditions such as hypertension, heart failure, and its possible therapeutic use in cardiovascular diseases. AIM: Study of the effect of neuropeptide Y on the frequency of spontaneous activity and amplitude-time parameters of the myocardium contraction of the rats’ right atrium during different periods of postnatal ontogenesis. MATERIAL AND METHODS: The experiments used 73 white outbred rats of 7 days (n=23), 21 days (n=25) and 100 days (n=25) of age. Using the classical strain-gauge method, the parameters of isometric contraction of isolated rat atrial myocardium were determined with the addition of a non-selective Y-receptor agonist. The isometric contraction curve was processed using the Chart 8.0 program. Statistical processing of the results was performed in MS Excel and IBM SPSS Statistics 2020. The significance of the differences was calculated using the Student’s t test. Data were presented as mean ± error of mean (M±m); n was the number of atrial myocardium preparations used. Changes were considered statistically significant at p 0.05. RESULTS: Neuropeptide Y at a concentration of 10–7 M reduces the frequency of spontaneous activity of the right atrium strips of rats with a preserved sinus node in 7, 21 and 100-day-old animals by 8.1%, 15% (p=0.038) and 7.9% (p=0.046) respectively in comparison with the control value. The amplitude of isometric contraction of the atrial myocardium in 7-day-old animals decreases by 12.4% (p=0.041), the duration of contraction decreases in 21-day-old animals by 12% (p=0.040), and in 100-day-old animals does not change compared to control. CONCLUSION: Neuropeptide Y reduces the frequency of spontaneous activity, increases the contraction duration, reduces the isometric contraction amplitude of rat myocardial strips in early postnatal ontogenesis.

Dopamine receptors and key elements of the neurotrophins (BDNF, CDNF) expression patterns during critical periods of ontogenesis in the brain structures of mice with autism-like behavior (BTBR) or its absence (С57BL/6 J).

Analysis of the mechanisms underlying autism spectrum disorder (ASD) is an urgent task due to the ever-increasing prevalence of this condition. The study of critical periods of neuroontogenesis is of interest, since the manifestation of ASD is often associated with prenatal disorders of the brain development. One of the currently promising hypotheses postulates a connection between the pathogenesis of ASD and the dysfunction of neurotransmitters and neurotrophins. In this study, we investigated the expression of key dopamine receptors (Drd1, Drd2), brain-derived neurotrophic factor (Bdnf), its receptors (Ntrkb2, Ngfr) and the transcription factor Creb1 that mediates BDNF action, as well as cerebral dopamine neurotrophic factor (Cdnf) during the critical periods of embryogenesis (e14 and e18) and postnatal development (p14, p28, p60) in the hippocampus and frontal cortex of BTBR mice with autism-like behavior compared to the neurotypical C57BL/6 J strain. In BTBR embryos, on the 14th day of prenatal development, an increase in the expression of the Ngfr gene encoding the p75NTR receptor, which may lead to the activation of apoptosis, was found in the hippocampus and frontal cortex. A decrease in the expression of Cdnf, Bdnf and its receptor Ntrkb2, as well as dopamine receptors (Drd1, Drd2) was detected in BTBR mice in the postnatal period of ontogenesis mainly in the frontal cortex, while in the hippocampus of mature mice (p60), only a decrease in the Drd2 mRNA level was revealed. The obtained results suggest that the decrease in the expression levels of CDNF, BDNF-TrkB and dopamine receptors in the frontal cortex in the postnatal period can lead to significant changes in both the morphology of neurons and dopamine neurotransmission in cortical brain structures. At the same time, the increase in p75NTR receptor gene expression observed on the 14th day of embryogenesis, crucial for hippocampus and frontal cortex development, may have direct relevance to the manifestation of early autism.

The Effect of Hypokinesia on the Dynamics of the Formed Elements of Blood during the Embryonic Period of Prenatal Development in Pregnant Rabbits

The erythroformula and leucoformula indicators changed in the rabbits that experienced hypokinesia during the embryonic stage of pregnancy. Compared to the rabbits that spent the pregnancy period under normal conditions, changes in concentrations of leukoformula indicators such as leukocytes, lymphocytes, monocytes, and granulocytes were detected in rabbits exposed to hypokinesia. While significant changes in erythroformula indicators: erythrocytes, average corpuscular volume of erythrocytes and hemoglobin capacity, erythrocyte sedimentation rate did not occur. The results of our studies have shown that prenatal hypokinesia causes noticeable changes in the blood coagulation system. On the other hand, changes in the coagulation system under the influence of prenatal hypokinesia were found to occur in the first periods of postnatal ontogenesis, had a continuous nature, and were maintained until the full maturity of postnatal development. Due to the effect of the hypokinesia factor, the changes in the mentioned indicators lead to the emergence of severe pathological diseases in most cases.

Tissue Interactions in Dense Tissues of the Orofacial Region in Patients with Connective Tissue Dysplasia.

This study aimed to investigate the rate and quality of maturation of the mineral component of impacted teeth 38 and 48 and a fragment of the human lower jaw with connective tissue dysplasia (CTD) in different periods of postnatal ontogenesis. The study involved 102 males (76 with CTD and 26 without CTD), divided into age groups: 31-40, 41-50 and 51-60 years. For medical reasons, teeth 38 and 48 were removed from each patient, as well as a fragment of the alveolar part of the lower jaw in the projection of teeth 38 and 48 measuring 0.5 × 0.5 cm. The odontological parameters, the mineral density of the enamel and the lower jaw, the length and width of the enamel prisms, the spatial organisation of collagen fibrils and the dimensions of the bone plates of the lower jaw were determined. A decrease in optical density was observed at the age of 41-50 and 51-60 years with dysplasia, which indicated a decrease in mineral density and the presence of total areas of hypomineralisation relative to the age of 31-40 years. In the age groups of 41-50 and 51-60 years, pronounced sclerosis and deformation of the delimiting elements were observed at the border of the connective tissue structures and the periosteum. At the age of 31-40 years, the level of stratification of the bone plates was local; after 40 years, it was generalised. Progressive osteoporosis of the lower jaw and incomplete amelogenesis are obstacles to the correct and harmonious eruption of the lower 'wisdom' teeth after 30 years.

Morphological features of the poultry thymus

This article reviews the literature on the morphological features of the poultry thymus. Since the preservation of livestock and disease prevention is a constant problem, the issue of poultry care will always remain in the forefront. Efforts to preserve the population and increase their productivity are directly related to strengthening poultry immunity and the state of their immune system. The study of the morphology of immune system organs allows us to objectively assess the effectiveness of methods for the prevention and treatment of various diseases, as well as to identify critical periods of development of the immune system and the body as a whole. When assessing the immune status of poultry, much attention is paid to the state of lymphoid organs, including the thymus. Currently, aspects related to the dynamics of development of immunocompetent organs during the postnatal period of ontogenesis and the time frame of their involution remain unresolved. Understanding the morphological features of the thymus and its changes is a key element in assessing the function of the immune system. It was found that with the growth and development of chicks, the absolute and relative weight of the thymus increases. However, at the onset of reproductive maturity, these values decrease significantly. Involution of the thymus mass occurs, the boundary between cortical and cerebral substances becomes less distinct, and the cellular composition of the thymus changes. The process of age-related involution is accompanied by a decrease in lymphoid tissue and T-lymphocytes. It is worth noting that the total number of circulating T-lymphocytes remains stable, as this population includes long-lived cells that do not require constant renewal. In this context, there is a change in the ratio of cortical and cerebral substances, the growth of connective tissue stroma and adipose tissue. It is noted that stress factors are one of the causes of early thymic involution, and the degree of development and morphological state of the thymus significantly affect the body's resistance to infections. Changes in the structure and morphometry of the chicken thymus can be an important criterion for the morphological diagnosis of immunodeficiencies in poultry.

Dynamics of progesterone, estradiol, cortisol, triiodothyronine and indicators of adaptive immunity concentrations in female dogs during estrus

In different periods of postnatal ontogenesis in dogs, as well as in other animals, there are critical physiological periods, the adequacy of which depends on immunoendocrine homeostasis. The estrus in bitches is a critical period because it lasts longer than in other mammals and has specific endocrine and immune changes in the body. In this study authors demonstrated the dynamics of changes in hormone content and indicators of adaptive cellular immunity in bitches during the estrus. Determination of these indicators does not require expensive laboratory equipment and is available in veterinary practice. Taking into account the fact that estrus in dogs lasts long enough, it is not clear enough what indicators and in what terms should be determined for predicting possible dysfunctions of the reproductive system and, as a result, premature impossibility of reproduction in bitches. The peak concentration of progesterone occurs on the 20th day of estrus, the reaction of the immune system, which is manifested by the maximum decrease in the phagocytic activity of neutrophils, should be noted. An increase in the concentration of estradiol on the 5th day of estrus, in contrast to progesterone, had the opposite effect on phagocytic activity of neutrophils, namely, the ability of neutrophils to phagocytosis increased. Further, we conducted clinical animals’ observations for three months after estrus for the possibility of inflammatory processes in the reproductive system development. According to the obtained indicators, no complications were found.

Age dynamics of the live weight of steers of Auliekol breed of different body type

The study of economically useful traits of Auliekol breed has of a big theoretical and practical interest for the Republic of Kazakhstan, because it is a relatively young breed, local in the place of breeding and complex in the set of genes, requiring further consolidation and development of heredity, increasing the diversity of the genealogical structure. The purpose of the research was to study the age dynamics of the live weight of steers of Auliekol breed of diff erent body type. The results of studies of the peculiarities of growth and development of beef cattle of Auliekol breed in the postnatal period of ontogenesis, when the fi nal formation and functional formation of all organs, body systems takes place and the genetic potential of animals is fully manifested have been presented in the paper. The research results can serve as a basis for improving traditional and adapted feeding and housing technologies, breeding methods, including with the involvement of the best gene pool of foreign breeds, and also allow to further increase the productivity potential of Auliekol breed. It was found that steers of compact body type (the 2nd group) during the whole experiment were inferior in live weight and absolute growth to herdmates of tall and stretched type (the 1st group). The steers of the 1st group for the period from birth to weaning exceeded the herdmates of the 2nd group by 8 % in terms of body weight gain, after weaning up to 18 months by 17 % and for the all experimental period by 10 %. These data indicate the superiority of tall-type steers in absolute values of live weight gain.

The Influence of Preterm Birth on the Development of Rat Myocardium in the Early Postnatal Period of Ontogenesis

The Influence of Preterm Birth on the Development of Rat Myocardium in the Early Postnatal Period of Ontogenesis

Morpho-functional changes of the harderian gland during vaccination

In poultry farms keep large poultry and demand permanently attention to their health. Seeing, the issue of conservation of livestock and prevention of bird disease will always be relevant. The task of conserving birds and increasing their productivity is inseperate linked to increasing natural resistance and the state of the immune system. An urgent problem in poultry farming is the choice of optimal vaccination programs for poultry. The study of the morphology of the immune system of birds allows to objectively assess the effectiveness of methods of prevention and treatment of diseases of various etiologies, as well as to identify critical periods of development of the immune system and the whole organism. Harderian gland is a peripheral organ of immune protection of birds, which is involved in the activation, differentiation of B-lymphocytes and proliferation of plasma cells. The purpose of the article is to systematize and describe the results of studies of the morphology of the ward gland of chickens for vaccine prophylaxis. It is established that the main morphological changes in the body during vaccine prophylaxis are: hyperplastic processes of lymphocytes and macrophages, as well as cellular transformation, which leads to the development of plasma cell response. As a result, there is an increase in the area of lymphoid tissue and an increase in the number of plasma cells in the ward gland. Morphofunctional changes in the harderian gland of chickens are due to age in the postnatal period of ontogenesis, and also depend on the frequency of vaccination. This review article is devoted to the study of the morphology of the harderian gland of chickens during vaccination. Data on the assessment of the morphofunctional state of the bird's harderian gland should be taken into account when conducting vaccine prophylaxis. In addition, a set of structural and morphometric changes in the harderian gland of chickens during vaccination may be one of the criteria for morphological diagnosis of avian immunodeficiencies.

APPROXIMATION OF GROWTH INDICATORS AND ANALYSIS OF INDIVIDUAL GROWTH CURVES BY LINEAR DIMENSIONS OF TUBULAR BONES IN CHICKENS OF MEAT PRODUCTION DIRECTION DURING POSTNATAL PERIOD OF ONTOGENESIS

Medical and biological sciences, including morphology, now require the introduction of the latest information technologies and mathematical methods to process the obtained and accumulated research results. To study the growth dynamics of body weight in domestic birds, classical growth models, Gompertz, were used for the purpose of quantitative description of the growth processes in biological objects, in particular for the growth and development of birds – Von Bertalanffy, Richards, and hyperbolastic models. The research material was tubular bones of the thoracic (humerus, ulna, and radius) and pelvic (femur, tibia, and tarsometatarsus) limbs in birds of meat production (broiler chickens and laying hens from the parent broiler flock of Cobb-500 strain) of different age groups during the postnatal period of ontogenesis. An appropriate regression analysis of experimental data based on known growth models was performed to solve the goal of obtaining growth curves and identifying special points (extremes, inflections, etc.), to build a picture of the overall development of the body as a whole and individual bones of the extremities. The most biologically suitable growth models for describing the growth dynamics of the body as a whole and individual studied bones were determined. The absence of a unified growth model of linear parameters of different tubular bones in meat producing chickens during the postnatal period of ontogenesis was established. This implies the need for a clear selection of growth models taking into account age, species, breed, keeping and feeding conditions of domestic birds. The growth model that best describes the body weight dynamics of broiler chickens is the hyperbolastic growth model of the H3 type, and in laying hens from the parent broiler flock – the Brody growth model.

Anatomy and histology of the thymus of American mink genotypes Standard, Sapphire, Lavander in the early postnatal period of ontogenesis

Data are presented on the thymus structure of American Mink of the Standard, Sapphire, Lavender colouring genotypes in the early postnatal period from birth to 180 days. The thymus is known to be a fully formed organ at birth. The anatomical structure of the thymus and its topography are not determined by genotype. At 45 days of age, the changes are manifested by an increase in the thymic lobule area and the brain matter therein, a decrease in the cortex area; the most intense growth of the thymus due to the rise in the number of lobules is noted. The thymus of mink at 45 to 90 days of age is characterised by an equalisation between the genotypes, increasing cortical area values to about the level of newborn mink with a corresponding increase in the cortical-brain index. The thymus of minks at the age of 90 to 180 days retains the typical morphological structure. Still, the signs of age involutive processes are seen – reduction of the lobule area, enlargement of the medulla, changes in the form of the organ (lobule fusion), increased signs of fat transformation thymus. Hassall’s corpuscles were found in the medulla in all periods of investigation. The number of Hassall’s bodies and their morphology depends on the functional activity of the thymus. In newborns, unicellular, young and juvenile forms predominate. In 45-day-old minks, young and immature forms predominate. In 90-day-old female and male Standard burros, young and quite often unicellular bodies are visualised, while mature and juvenile records are less common. In mink of the coloured genotypes, immature and youthful Hassall’s corpuscles are predominant. By 180 days, the number of mature and young corpuscles with signs of central cell destruction with detritus accumulation and cavity formation increases.

Content and location of lymphocyte subpopulations with markers CD4+, CD8+ and CD20+ in the esophageal tonsil of chickens and the Meckel diverticulum of ducks

Immune formations of birds' digestive organs, including the esophageal tonsil and Meckel’s diverticulum, protect the body from foreign antigens that enter the body with food and water and play an important role in maintaining the genetic constancy of its internal environment. This unique property of the immune system is formed during ontogenesis and is associated with maintaining the selection of lymphocyte clones that are able to respond to foreign antigens and carry out a specific immune response of two types: humoral and cellular. This article presents the results of a study of T- and B-lymphocyte subpopulations of the esophageal tonsil of Shever 579 cross chickens at the age of 25, 180 and 300 days, the Meckel diverticulum of the Blagovarsky cross ducks at the age of 30, 150 and 180 days. Immunohistochemical and statistical research methods were used to determine the localization and quantitative parameters of cell populations of lymphocytes (CD4+, CD8+, CD20+) using monoclonal antibodies and the DAKO EnVision FLEX+ imaging system (Dako Cytomation, Denmark). Separate subpopulations of T-lymphocytes (CD4+ - helpers, CD8+ -cytotoxic / T-suppressors) and mature B-lymphocytes (CD20+) were found in the esophageal tonsil and Meckel diverticulum of birds. Their presence confirms that antigen-independent proliferation and differentiation of lymphocytes into effector cells occur in the immune formations of the digestive system. The lymphoid tissue of these formations is represented mainly by a well-defined diffuse form and nodules with light centers (secondary). In the esophageal tonsil of chickens, these structures are located in the tunica mucosa and tela submucosa, and in the Meckel diverticulum of ducks – also in the tunica muscularis. The content of lymphocytes with these markers predominates in diffuse lymphoid tissue compared to that in secondary lymphoid nodules. In the diffuse lymphoid tissue of the esophageal tonsil, lymphocytes are located mainly near the adenomeres and excretory ducts of the esophageal glands, blood vessels, and under the surface epithelium, and in Meckel’s diverticulum – around the crypts, in their epithelium and in the epithelium of the villi. They are also found in the light centers of lymphoid nodules and on their periphery. The indices of the content of lymphocytes with the indicated markers in the esophageal tonsil and Meckel diverticulum which we determined were associated with age characteristics of the poultry in the postnatal period of ontogenesis. According to our observations, the content of CD20+ lymphocytes was the highest, while the populations of CD4+ and CD8+ lymphocytes were much smaller. This indicates an increase in the activity and predominance of the humoral immunity over the cellular one. The content of CD20+ lymphocytes was highest in birds at the age of 180 days, that is, during their sexual maturity. The data presented in the work can be used by morphologists researching the organs of the immune system, immunologists, poultry specialists involved in breeding, using and raising poultry and in educational work.

Cytokine profile in the subjects after long-term <i>in utero</i> and postnatal exposure to chronic irradiation

Persons exposed to ionizing radiation in utero and in early childhood constitute a risk group for the development of long-term stochastic consequences of irradiation. The imbalance of cytokines at the long terms after irradiation could be considered a carcinogenic triggering factor in subjects previously irradiated in utero and in early childhood, thus determining relevance of the study. The aim of the present study was to assess the levels of serum cytokines in native residents of coastal villages at the Techa River, whose chronic irradiation had been begun antenatally and to study probable interrelatirons between the detected changes, radiation and non-radiation factors at long terms after the exposure was begun. The main group included 61 persons from the Techa River Cohort who were born in 1950-1960, whose irradiation was begun in utero, being continued over the early postnatal period. For patients from the main group, the mean dose of antenatal radiation was calculated 74.7 mGy for red bone marrow as of, the mean dose of postnatal irradiation was calculated for red bone marrow as 537.5 mGy, and the median age of patients was 64.0 years. The comparison group (90 nonirradiated persons) was comparable to the main group in terms of age, gender, ethnicity and socio-economic status. The median levels for IL-2 in the main group were 1.37 pg/ml; in the comparison group, 2.70 pg/ml, p = 0.020; for IL-10, 4.53 pg/ml versus 7.58 pg/ml, p = 0.030 respectively; for GM-CSF, 0.39 pg/ml in the subjects who were irradiated in utero and in the early postnatal period versus 0.86 pg/ml in non-irradiated persons, p = 0.040. The median serum concentrations of IL-1β, IL-1α, IL-1(ra), IL-4, IL-6, IL-8, G-CSF, TNFα, IFNα, IFNγ in the study group did not show differences from the values in a group of non-irradiated persons. The decrease of the serum IL-2, IL-10 and GM-CSF levels in the persons of the main group did not depend on the dose of antenatal irradiation to red bone marrow, and on the radiation dose to red bone marrow received during the postnatal period of ontogenesis. In the main group, there was a moderate inverse relationship between the serum IL-10 level and age at the time of examination (SR = -0.53, p 0.001). Serum concentrations of IL-2 and IL-10 in the people from comparison group showed a moderate positive correlation with their present age (SR = 0.47, p 0.001 and SR = 0.42, p 0.001 respectively).

МОРФОЛОГИЯ ВЕНОЗНОЙ СИСТЕМЫ ПОЧЕК СОБАК В ПОСТНАТАЛЬНОМ ПЕРИОДЕ ОНТОГЕНЕЗА

The article presents data on the dynamics of morphometric parameters of the diameter of the caudal vena cava and renal veins of dogs in the postnatal period of ontogenesis, the peculiarities of the course and branching of extra- and intraorganic venous vessels of the kidneys of dogs, as well as the formation of the right and left renal veins in the gates of the organ. The increase in the diameter of the caudal vena cava and renal veins of dogs in the postnatal period of ontogenesis is uneven. An intense increase in the diameter of the caudal vena cava in dogs was detected at 3 months. and seven years. The diameter of the renal veins increases rapidly by 3 months. the age of the animals. In most cases, the intraorgan renal veins of the dogs on the right and left form one trunk of the efferent renal vein. The formation of the right renal vein in the gates of the organ occurs in three ways: two, three and four trunks, and the left renal vein by the fusion of two interlobar veins. The double trunk of the right renal vein is rarely recorded. The data obtained in the course of morphological study on the venous system of the kidneys of dogs can be used for op-erative access to organs.

Microstructure of the nerve plexus of the muscular membrane of the gut of domestic ducks (Anas platyrhynchos domesticus) of different ages

As evidenced by the publications of recent years, contrary to the existing dogma about the immutability of the state of the enteric nervous system during the postnatal period of ontogenesis, the population of intestinal neurons is a dynamic formation, decreasing with age and changing due to the action of environmental factors. The current article presents the results of study of the microscopic structure of the nerve plexus of the muscular membrane of the enteric nervous system of domestic ducks (Anas platyrhynchos domesticus) of the black white–breasted breed, of nine age groups of 1–365 days of age. The topography, number, area of nerve nodes, as well as the density of neurons in them were determined on transverse sections of the duodenum, jejunum, ileum, caecum and rectum. For the purpose of a generalized assessment of the morphofunctional state of the nerve plexuses, two parameters were determined: the average age indicator of the gut and intestines. The average age indicator of a certain structure of each intestine was determined as the arithmetical average of its nine age indicators. The average age indicator of a certain gut structure was determined as the arithmetic average of the average age indicator of the structure of all five intestines. It has been established that the nerve plexus of the muscular membrane (myenteric, plexus Auerbachi) of the gut of domestic ducks, in contrast to mammals, is not located between the layers of the muscular membrane, but in its outer layer. On a transverse section of the gut wall, the myenteric ganglia and cords that connect have a predominantly elliptical shape. Despite a significant increase with age in the diameter and thickness of the gut wall, the total number of myenteric ganglia changed little, increasing or decreasing with varying degrees of reliability relative to the previous age. In the gut of ducks, during the first year of the postnatal period of ontogenesis, the smallest number of myenteric ganglia was found in the cecum, and the largest – in the ileum. The general pattern of the dynamics of the size of the myenteric ganglia of the gut of ducks was an increase in their area with age. Moreover, this indicator reached the greatest value at different ages of ducks: at 30 days of age in the ileum and cecum, at 180 days of age – in the rectum and at 365 days of age – in the duodenum. The smallest area of the myenteric ganglia was found in the jejunum, and the largest – in the duodenum and ileum. The smallest number of neurons in the ganglion was found in the cecum, and the largest – in the rectum, the lowest density of neurons in the ganglion was found in the cecum, and the largest – in the jejunum. The general quantitative pattern of neurons in the ganglion was the decrease in their density with age. Changes in the morphometric parameters of the ganglia of the nerve plexus of the muscular membrane of the ducks’ gut indicate the plasticity of the enteric nervous system, its ability to dynamically respond to the action of factors of the internal and external environment. It is promising to study the state of the submucous nerve plexus, as well as the cellular composition of the population of neurons of the enteric nervous system of domestic and wild poultry.

Вікова динаміка анатомічних показників шлунку і кишечнику хвилястого папуги (Melopsittacus undulatus)

The object of research was the morphofunctional organization of the stomach and intestinal of the budgerigar (Melopsittacus undulatus) in the postnatal period of ontogenesis. The aim of the work was to determine the age topography and anatomical structure characteristics of the stomach and intestines from the budgerigar (Melopsittacus undulatus). The material for morphological studies was selected from budgerigars of 9 groups: 1-, 3-, 7-, 14-, 21-day-old, 1-, 2-, 6-month-old and 1-year-old (n = 5). The absolute bodyweight of parrots and their organs was determined using a ВЛКТ-500 balance and a «Techniprot Waga Torsyjna-WT 500» torsion balance. Linear indicators of organs were determined using a ruler (GOST 17485-72) and a calliper (GOST 166-89). According to the research results, it was found that the increase in body weight of parrots during the first year of life was uneven. In the first month, it was increased by 15.3 times, in the second month – by 1.1 times. During the first month, it was increased most intensively in the first week. Parrots reached the mass of an adult bird at the age of 2 months. During the first year of life, the greatest body weight was established at the age of 6 months, and the greatest absolute weight, linear indicators of the glandular and muscular parts of the stomach, as well as the intestines – at the age of 21 days. The glandular stomach of the budgerigar reached the highest relative weight indicators at the age of 3 days, and the muscular part of the stomach and intestines – at the age of 7 days. The length of the intestine increased most intensively in the first week of life. During the first year of life, the relative length of the budgerigars small intestine gradually decreased. The greatest indicators of the duodenal absolute length were established at the age of 60 days, lean – 60 days, ileum – 21 days. The greatest indicators of the duodenal relative length were established at the age of 30 days, jejunum – 7 days, ileum – 14 and 21 days. High linear indices, as well as indices of the stomach and intestines mass of budgerigars, indicated their key importance in providing the body with nutrients and biologically active substances during intensive growth.

Influence of steer genotypes on the features of muscle development in the postnatal period of ontogenesis

The study of the carcass muscles development was carried out on Simmental and Kazakh White-Headed steers and their first generation hybrids. At the age of 18 months, the control slaughter of 3 steers of different genotypes was carried out: I - Simmental, II - Kazakh White-Headed, III - 1/2 Kazakh White-Headed x 1/2 Simmental. To study the development of muscle groups and individual muscles by anatomical regions, the left half-carcasses were prepared, taking into account the methodical instructions. To facilitate the analysis of the material, the muscles were grouped according to the relevant joints and the topographic location by the generally accepted pattern. The muscles development was studied using the data on the absolute mass of individual muscles and muscle groups. It was established that the steers of group III surpassed those of groups I and II in the total muscle mass of the spinal column, which was 1.28-0.45 kg (10.85-3.56%), the total muscle mass of the shoulder girdle - 1.45-0.51 kg (9.78-3.51%), thoracic limb - 0.72-0.25 kg (9.77-3.43%), pelvic limb - 3.16-1.11 kg (9.78-3.45%) and, in general, throughout the half-carcass of the muscles considered - 6.62-2.33 kg (9.79-3.44%).

ОЦЕНКА ФИЗИОЛОГИЧЕСКОГО СОСТОЯНИЯ ОРГАНИЗМА СТАНДАРТНОЙ ЧЕРНОЙ НОРКИ (NEOVISON VISON) В РАЗЛИЧНЫЕ БИОЛОГИЧЕСКИЕ ПЕРИОДЫ

The aim of the study was to investigate the white blood cells morphology in female short-haired mink of the standard black breed in different periods of postnatal ontogenesis with the existing technology of keeping and feeding. The experiment was carried out on repair females of the short-haired standard black mink (+/+), bred in the animal farm of JSC «Breeding animal Farm «Saltykovsky» of the Moscow region. Blood samples for differential leukocyte count determination were taken in 10 females aged 4 months and 10 months, to monitor the physiological state of females in different periods of minks’ postnatal ontogenesis. Blood was taken from the finger in the morning before feeding. Peripheral blood smears were stained using May-Grunwald method for leukocyte count determination. New data on age-related changes in the leukocyte count of female short-haired mink were obtained. A decrease of the number of lymphocytes, eosinophils, monocytes (p<0,05) and an increase in neutrophils (p<0,001) in the blood correlated with the age of the females was found (at 4 months relative to 10 months), these changes have the similar trend as in longer hairline minks. A higher content of neutrophils 46,6-62,5% and eosinophils 3,9-7,2% was determined in comparison with dark brown (+/+) minks, which may be due to the genotypic features of black minks. The following indicators of productivity in the studied females were established: Breeding performance was 5,63±0,64 puppies, young animals productivity on the main female was 4,40±0,77 puppies. The obtained data characterize the physiological state of the animal organism in the adaptation process to the existing technology of keeping and feeding, and can be used for evaluation and research the impact of various factors that ensure the realization of genetic potential on minks’ organism.

Ultrastructural characteristics of the anterior pituitary gland of cattle in the definitive period of postnatal ontogenesis

Today much attention is paid to the study of the pituitary ultrastructure of laboratory animals and humans. But there is not enough available literature to study the most important organ of internal secretion of productive animal. The aim of our work is to study the structure of the ultrastructure of cells of the anterior pituitary gland of cattle in the definitive period of postnatal ontogenesis. Histological, morphometric, and electron microscopic techniques were used to study the cellular composition of the anterior pituitary gland of cattle. It was revealed that the anterior lobe of the pituitary gland occupies 64 % of the entire pituitary parenchyma, while the posterior and middle lobes occupy 27% and 9%, respectively. After using general histological methods there are detected the functionally inactive chromophobes (41%) and chromophilic cells, which include acidophils (38%) and basophils (21%) in the anterior lobe of the pituitary gland. The electron microscopic studies in the parenchyma of the anterior pituitary gland let find Somatotropes that differ in the presence of a large number of secretory granules in the cytoplasm. Lactotropes are less common than somatotropes and differ from them in larger secretory granules. Corticotropes, gonadotropes and thyrotropes with a minimum content of secretory granules are the least detected. All identified endocrine cells are at different stages of functional activity.

Microscopic structure of the rectum of the domestic duck

As a rule, researchers pay less attention to the features of the large intestine than to the small intestine. The purpose of the study was to determine the features of the microscopic structure of the rectum of ducks during the first year of the postnatal period of ontogenesis. For histological examinations, the material was selected from Ukrainian white-breasted ducks of 9 age groups: 1-, 3-, 7-, 14-, 21-day-old, 1-, 2-, 6-month-old and 1-year-old. Morphometric parameters of microstructures were set on cross sections of the midgut. The general change pattern in the morphometric parameters of the microstructures of the rectum of ducks was their increase, which was asynchronous and uneven. There was observed an active intestinal morphogenesis continued, as evidenced by the process of formation of villi and crypts in the group of 1-3-day-old ducks. The most intensive morphometric parameters of the rectum changed in the first month of the postnatal period of ontogenesis, during which – in the first week. In the first week, first and second month of life of ducks, the wall thickness of the rectum increased by 93.1, respectively; 199.5 and 20.4 %, the thickness of the mucous membrane – 81.0; 167.1 and 19.5 %, the thickness of the muscular membrane – by 126.1; 285.3 and 22.7 %, the height of the villi – by 113.2; 208.7 and 7.2 %, the width of the villi – by 84.7; 70.9 and 12.5 %, their surface area – by 293.8; 427.6 and 20.6 %, the depth of the crypt – by 85.1; 49.9 and 52.3 %, muscle plate thickness – by 254.0; 750.8 and 15.0 %. The most stable indicators of the rectum during the first year of the postnatal period of ontogenesis were the density of villi and crypts, the number of which after 7 days of age had no significant difference compared to that of a younger age. The indicates of adult birds morphometric parameters of the rectum of ducks corresponded at different ages: in 1-year-old – the thickness of the serous membrane and the density of villi; at 6 months – the diameter of the intestine, the surface area of the villi; at 2 months of age – the thickness of the wall and its mucous membrane, the width of the villi, the depth of the crypt; at 1 month – the thickness of the muscular membrane and plate, the height of the villi, the epithelium of the villi and crypt; at 3 days of age – the density of crypts; at 1 day of age – the width of the crypt.