Age features immunological status of animals
In the embryonic period, the immunological status of the fetal organism is characterized by the synthesis of its own protective factors. At the same time, the synthesis of natural resistance factors outstrips the development of specific response mechanisms.
Of the factors of natural resistance, cellular elements are the first to appear: first monocytes, then neutrophils and eosinophils. In the embryonic period, they function as phagocytes, possessing an exciting and digesting ability. Moreover, the digestive capacity prevails and does not change significantly even after the intake of colostrum by newborn animals. By the end of the embryonic period, lysozyme, properdin and, to a lesser extent, complement accumulate in the fetal circulation. As the fetus develops, the level of these factors gradually increases. In the prefetal and fetal periods, immunoglobulins appear in the fetal blood serum, mainly class M and less often class G. They have the function of predominantly incomplete antibodies.
In newborn animals, the content of all protection factors increases, but only lysozyme corresponds to the level of the maternal organism. After taking colostrum in the body of newborns and their mothers, the content of all factors, with the exception of complement, levels off. The complement concentration does not reach the maternal level even in the serum of 6-month-old calves.
Saturation of the blood flow of newborn animals with immune factors occurs only by the colostral route. Colostrum contains a decreasing amount of IgG1, IgM, IgA, IgG2. Immunoglobulin Gl approximately two weeks before calving selectively passes from the bloodstream of cows and accumulates in the udder. The remaining colostral immunoglobulins are synthesized by the mammary gland. Lysozyme and lactoferrin are also formed in it, which, together with immunoglobulins, represent humoral factors of local udder immunity. Colostrum immunoglobulins pass into the lymph and then the bloodstream of a newborn animal by pinocytosis. In the crypts of the small intestine, special cells selectively transport molecules of colostrum immunoglobulins. Immunoglobulins are most actively absorbed when drinking colostrum to calves in the first 4..5 hours after birth.
The mechanism of natural resistance changes in accordance with the general physiological state of the animal organism and with age. In old animals, there is a decrease in immunological reactivity due to autoimmune processes, since during this period there is an accumulation of mutant forms of somatic cells, while immunocompetent cells themselves can mutate and become aggressive against normal cells of their body. A decrease in the humoral response was established due to a decrease in the number of plasma cells formed in response to the introduced antigen. It also reduces the activity of cellular immunity. In particular, with age, the number of T-lymphocytes in the blood is much less, there is a decrease in reactivity to the injected antigen. With regard to the absorption and digestion activity of macrophages, no differences have been established between young animals and old ones, although the process of freeing blood from foreign substances and microorganisms is slowed down in old ones. The ability of macrophages to cooperate with other cells does not change with age.
immunopathological reactions.
Immunopathology studies pathological reactions and diseases, the development of which is due to immunological factors and mechanisms. The object of immunopathology is a variety of violations of the ability of immunocompetent cells of the body to distinguish between "own" and "alien", own and foreign antigens.
Immunopathology includes three types of reactions: reaction to self antigens, when immunocompetent cells recognize them as foreign (autoimmunogenic); a pathologically strongly pronounced immune reaction to an allergen, a decrease in the ability of immunocompetent cells to develop an immune response to foreign substances (immunodeficiency diseases, etc.).
Autoimmunity. It has been established that tissue breakdown occurs in some diseases, accompanied by the formation of autoantigens. Autoantigens are components of one's own tissues that occur in these tissues under the influence of bacteria, viruses, drugs, and ionizing radiation. In addition, the introduction of microbes into the body that have common antigens with mammalian tissues (cross-antigens) can serve as the cause of autoimmune reactions. In these cases, the animal's body, reflecting the attack of a foreign antigen, incidentally affects the components of its own tissues (often the heart, synovial membranes) due to the common antigenic determinants of micro- and macroorganisms.
Allergy. Allergy (from the Greek alios - another, ergon - action) - an altered reactivity, or sensitivity, of the body in relation to a particular substance, more often when it enters the body again. All substances that change the reactivity of the body are called allergens. Allergens can be various substances of animal or plant origin, lipoids, complex carbohydrates, medicinal substances, etc. Depending on the type of allergens, infectious, food (idiosyncrasy), drug and other allergies are distinguished. Allergic reactions are manifested due to the inclusion of specific defense factors and develop, like all other immune reactions, in response to the penetration of the allergen into the body. These reactions can be increased compared to the norm - hyperergy, can be lowered - hypoergy or completely absent - anergy.
Allergic reactions are divided according to manifestation into immediate hypersensitivity (HTH) and delayed-type hypersensitivity (DTH). NHT occurs after re-introduction of the antigen (allergen) after a few minutes; HRT appears after several hours (12...48), and sometimes even days. Both types of allergies differ not only in the speed of clinical manifestations, but also in the mechanism of their development. GNT includes anaphylaxis, atopic reactions, and serum sickness.
Anaphylaxis (from Greek ana - against, phylaxia - protection) - a state of hypersensitivity of a sensitized organism to repeated parenteral administration of a foreign protein. Anaphylaxis was first discovered by Portier and Richet in 1902. The first dose of an antigen (protein) that causes hypersensitivity is called sensitizing (lat. sensibilitas - sensitivity), the second dose, after which anaphylaxis develops, is resolving, and the resolving dose should be several times higher than the sensitizing one.
Passive anaphylaxis. Anaphylaxis can be artificially reproduced in healthy animals in a passive way, i.e., by introducing the immune serum of a sensitized animal. As a result, the animal develops a state of sensitization after a few hours (4...24). When such an animal is injected with a specific antigen, passive anaphylaxis occurs.
Atopy (Greek atopos - strange, unusual). Atopy refers to HNT, which is a natural hypersensitivity that occurs spontaneously in people and animals predisposed to allergies. Atopic diseases are more studied in humans - these are bronchial asthma, allergic rhinitis and conjunctivitis, urticaria, food allergies to strawberries, honey, egg white, citrus fruits, etc. Food allergies are described in dogs and cats for fish, milk and other products, in cattle cattle noted an atopic reaction such as hay fever when transferred to other pastures. In recent years, atopic reactions caused by drugs - antibiotics, sulfonamides, etc.
Serum disease. Serum sickness develops 8-10 days after a single injection of foreign serum. The disease in humans is characterized by the appearance of a rash resembling hives, and is accompanied by severe itching, fever, impaired cardiovascular activity, swelling of the lymph nodes and proceeds without death.
Delayed type hypersensitivity (DTH). For the first time this type of reaction was discovered by R. Koch in 1890 in a patient with tuberculosis with subcutaneous injection of tuberculin. Later it was found that there are a number of antigens that stimulate predominantly T-lymphocytes and determine mainly the formation of cellular immunity. In an organism sensitized by such antigens, a specific hypersensitivity is formed on the basis of cellular immunity, which manifests itself in the fact that after 12–48 hours an inflammatory reaction develops at the site of repeated administration of the antigen. Her a typical example is a tuberculin test. Intradermal administration of tuberculin to an animal with tuberculosis causes edematous painful swelling at the injection site, an increase in local temperature. The reaction reaches a maximum by 48 hours.
Hypersensitivity to allergens (antigens) of pathogenic microbes and their metabolic products is called infectious allergy. It plays an important role in the pathogenesis and development of such infectious diseases as tuberculosis, brucellosis, glanders, aspergillosis, etc. When the animal recovers, the hyperergic state persists for a long time. The specificity of infectious allergic reactions allows them to be used for diagnostic purposes. Various allergens are prepared industrially in biofactories - tuberculin, mallein, brucellohydrolyzate, tularin, etc.
It should be noted that in some cases an allergic reaction is absent in a sick (sensitized) animal, this phenomenon is called anergy (unresponsiveness). Anergy can be positive or negative. Positive anergy is noted when the immunobiological processes in the body are activated and the contact of the body with the allergen quickly leads to its elimination without the development of an inflammatory reaction. Negative anergy is caused by the unresponsiveness of the cells of the body and occurs when the defense mechanisms are suppressed, which indicates the defenselessness of the body.
When diagnosing infectious diseases accompanied by allergies, the phenomena of paraallergy and pseudoallergy are sometimes noted. Paraallergy is a phenomenon when a sensitized (sick) organism reacts to allergens prepared from microbes that have common or related allergens, such as Mycobacterium tuberculosis and atypical mycobacteria.
Pseudo-allergy (hetero-allergy) - the presence of a non-specific allergic reaction as a result of autoallergization of the body by tissue decay products during the development of a pathological process. For example, an allergic reaction to tuberculin in cattle with leukemia, echinococcosis or other diseases.
There are three stages in the development of allergic reactions:
Immunological - connection of the allergen with antibodies or sensitized lymphocytes, this stage is specific;
pathochemical - the result of the interaction of the allergen with antibodies and sensitized cells. Mediators, a slowly reacting substance, as well as lymphokines and monokines are released from the cells;
pathophysiological - the result of the action of various biologically active substances on tissues. It is characterized by circulatory disorders, spasm of smooth muscles of the bronchi, intestines, changes in capillary permeability, swelling, itching, etc.
Thus, in allergic reactions, we observe clinical manifestations that are not characteristic of the direct action of the antigen (microbes, foreign proteins), but rather the same symptoms characteristic of allergic reactions.
Immunodeficiencies
Immunodeficiency states are characterized by the fact that the immune system is not able to respond with a full immune response to various antigens. The immune response is not just the absence or decrease in the immune response, but the inability of the body to carry out one or another link of the immune response. Immunodeficiencies are manifested by a decrease or complete absence of an immune response due to a violation of one or more parts of the immune system.
Immunodeficiencies can be primary (congenital) and secondary (acquired).
Primary immunodeficiencies are characterized by a defect in cellular and humoral immunity (combined immunodeficiency), either only cellular or only humoral. Primary immunodeficiencies arise as a result of genetic defects, as well as as a result of inadequate feeding of mothers during pregnancy, primary immunodeficiencies can be observed in newborn animals. Such animals are born with signs of malnutrition and are usually not viable. With combined immunodeficiency, the absence or hypoplasia of the thymus, bone marrow, lymph nodes, spleen, lymphopenia and low levels of immunoglobulins in the blood are noted. Clinically, immunodeficiencies can manifest themselves as a delay in physical development, pneumonia, gastroenteritis, sepsis, caused by an opportunistic infection.
Age-related immunodeficiencies are observed in young and old organisms. In young people, humoral immunity deficiency is more common as a result of insufficient maturity of the immune system during the neonatal period and up to the second or third week of life. In such individuals, there is a lack of immunoglobulins, B-lymphocytes in the blood, a weak phagocytic activity of micro- and macrophages. There are few secondary lymphoid follicles with large reactive centers and plasma cells in the lymph nodes and spleen. Animals develop gastroenteritis, bronchopneumonia, caused by the action of opportunistic microflora. Deficiency of humoral immunity during the neonatal period is compensated by full-fledged colostrum of the mother, and at a later time - by full feeding and good conditions content.
In old animals, immunodeficiency is caused by age-related involution of the thymus, a decrease in the number of T-lymphocytes in the lymph nodes and spleen. These organisms often develop tumors.
Secondary immunodeficiencies occur in connection with the disease or as a result of treatment with immunosuppressants. The development of such immunodeficiencies is observed when infectious diseases, malignant tumors, long-term use of antibiotics, hormones, inadequate feeding. Secondary immunodeficiencies are usually accompanied by impaired cellular and humoral immunity, i.e., they are combined. They are manifested by involution of the thymus, devastation of the lymph nodes and spleen, a sharp decrease in the number of lymphocytes in the blood. Secondary deficiencies, unlike primary ones, can completely disappear when the underlying disease is eliminated. Against the background of secondary and age-related immunodeficiencies, drugs may be ineffective, and vaccination does not create strong immunity against infectious diseases. Thus, immunodeficiency states must be taken into account in the selection, development of therapeutic and preventive measures in the economy. In addition, the immune system can be manipulated to correct, stimulate, or suppress certain immune responses. Such an effect is possible with the help of immunosuppressants and immunostimulants.
480 rub. | 150 UAH | $7.5 ", MOUSEOFF, FGCOLOR, "#FFFFCC",BGCOLOR, "#393939");" onMouseOut="return nd();"> Thesis - 480 rubles, shipping 10 minutes 24 hours a day, seven days a week and holidays
Agarkov Alexander Viktorovich Formation of the immunobiological status of newborn piglets: dissertation ... candidate of biological sciences: 06.02.01 / Agarkov Alexander Viktorovich; [Place of protection: Stavropol State Agrarian University]. - Stavropol, 2015. - 155 p.
Introduction
1. Literature review 12
1.1. The relationship of the functional systems of the body of the mother and fetus during pregnancy 12
1.2. Ontogenetic features of the newborn organism of farm animals 19
1.3. Immunobiological status of animals in the neonatal period 29
2. Own research 39
2.1. Materials and methods of research 39
3. Results of own research 48
3.1. Results of assessment of thermogenesis processes and metabolic potential in newborn piglets 48
3.2. The results of the assessment of the immunobiological status and the identification of its relationship with the processes of thermogenesis in newborn piglets... 54
3.3. Assessment of the immunobiological state of sows of different parity 57
3.4. The results of the study of the immunobiological status of piglets born from sows of different number of farrowings 61
3.5. Determination of the hypoxic state of sows during pregnancy 72
3.6. Influence of enteral oxygenation of pregnant sows on the indicators of the immunobiological status of their offspring 77
3.7. Development of a method for determining the viability of newborn piglets 88
4. Conclusion 98
4.1. Evaluation of the functional maturity of the processes of thermoregulation and immunobiological status in newborn piglets 98
4.2. Dependence of the viability of piglets on the perfection of the processes of thermoregulation and the level of metabolism on the first day after birth 101
4.3. The influence of the hypoxic state of the body of sows during fruiting on the development of the immunobiological system in their offspring 104
Findings 107
Practical suggestions 109
References 110
Introduction to work
Relevance of the research topic. Cultivation of healthy offspring, prevention of morbidity and safety of livestock is one of the primary tasks of animal husbandry. The difficulty of its implementation is that the body of a newborn in the first days after birth has a weak adaptive potential to the conditions environment(V. P. Voronyansky, 2001; L. I. Efanova, 2004; G. V. Makarov, V. N. Afonin, A. G. Shakhov,
A. I. Anufriev, 2005; V. V. Makarov, 2005; R. R. Gafarov et al., 2009).
From the earliest stages in newborns, basic defenses are activated.
mechanisms for responding to environmental impacts, and the main load
their immunobiological system accepts them (Yu. N. Fedorov, M. Yu. Gorbunova,
V. L. Solodovnikov, A. P. Golovchenko, 1983; R. R. Galaktionov, 1998; A. F. Bak-
Sheev, N. V. Efanova, P. N. Smirnov, K. A. Dementieva, 2003; A. Casadevall,
L. A. Pirofski, 2003; N. Devillers, C. Farmer, J. Le Dividich, A. Prunier, 2007).
It is generally accepted that the immunobiological response acts as a criterion in maintaining the relative constancy of the organism under external influence. According to a number of authors (S. I. Lyutinsky, N. V. Sadovnikov, B. G. Yushkov, 1998; Yu. N. Fedorov et al., 2000; A. G. Shakhov, 2009; A. F. Dmitriev, 2012; J. Le Dividich, J. A. Rooke, P. Herpin, 2005), immunobiological status can serve as an indicator of well-being for a newborn animal.
Scientists (K. V. Zhuchaev, S. P. Knyazev, V. V. Gart, 1994; V. P. Khlopitsky, Yu. V. Konopelko, K. A. Kriventsev, S. V. Palazyuk, 2009; R. J. Xu , S. H. Zhang, F. Wang, 2000; N. Devillers, C. Farmer, J. Le Dividich, A. Prunier, 2007) it was found that the neonatal period accounts for a significant waste, up to 80%, of animals born with reduced immunobiological parameters .
The immunobiological status in newborn animals is largely determined by the state of the maternal organism (R. M. Khaitov, 1995; E. V. Krapivina, Yu. N. Fedorov, V. P. Ivanov, 2001; E. S. Voronin, A. M. Petrov, M. M. Serykh, D. A. Devrishov, 2002; Yu. I. Nikitin, V. K. Gusakov, N. S. Motuzko, 2006; Yu. N. Fedorov, 2006; A. Gutzwiller, 2002; C. A. Siegrist , 2007). Despite the studies performed to determine the parameters of the formation of the immunobiological system in the "mother - fetus - newborn" complex, the question of the relationship between the homologous systems of the mother's body and offspring needs to be supplemented and resolved, and the study of the immunobiological interaction in the functional system "mother - fetus - newborn" will form the basis developments to obtain healthy offspring and predict their viability.
degree of development. Most of the studies on the formation of the immunobiological status are fragmentary (B. V. Novikov, V. V. Dmitrienko, 1993; R. M. Khaitov, 1995; I. M. Karput, 2000; E. V. Krapivina, Yu. N. Fedorov, V. P. Ivanov, 2001; E. S. Voronin, A. M. Petrov, M. M. Serykh, D. A. Devrishov, 2002; A. F. Baksheev, N. V. Efanova, P. N. Smirnov et al., 2003; M. A. Sidorov, Yu. N. Fedorov, O. M. Savich, 2006; H. Salmon, M. Berri, V. Gerdts, F. Meurens, 2009); the influence on the immunobiological system of various mediated factors - the sex of animals,
The survival and safety of newborn piglets under the prevailing growing conditions are topical issue in the pig industry. To improve the status of life, technological and therapeutic methods are used (S. I. Dzhupina, 2002; A. I. Brylin, A. V. Boyko, M. I. Volkova, 2007; R. R. Gafarov, T. P. Trifonova, A. G. Kuznetsov, L. A. Mikhailova, I. R. Kinzyabulatov, K. S. Nikolaeva, A. V. Deeva, G. G. Mekhdikhanov, 2009; J. E. Butler, M. Sinkora, N. Wertz, W . Holtmeier, C. D. Lemke, 2006), the main focus of which is methods and techniques to increase the immunobiological reactivity of the organism of piglets. But often these measures are late, as they are aimed at eliminating already formed structural and functional disorders (V. P. Voronyansky, 2001; I. M. Donnik, 2002; G. Kh. Ilyasova, 2002; N. N. Shulga, 2005 –2009; J. Gadd, 1990; J. Hales, V. A. Moustsen, M. B. Nielsen, C. F. Hansen, 2013). This, undoubtedly, is the cause of reduced natural resistance and immunobiological reactivity and, as a result, high morbidity and mortality.
In this regard, the development of simpler and more significant methods for selecting viable individuals as the main indicator of the productive and reproductive potential of a herd of farm animals is especially relevant. Thus, the development of new methods for the early detection and prevention of immunobiological immaturity with the prediction of viability are necessary in modern conditions for veterinary science and practice, requiring scientific study and justification.
Object of study: functional system "mother - fetus - newborn".
Subject of study: dynamic characteristics of the immunobiological status of the body of piglets, depending on the physiological state of pregnant sows during pregnancy.
Purpose of the study: to study the formation of the immunobiological status of newborn piglets.
Research objectives:
To study the features of the formation of the processes of thermoregulation and the immunobiological status of newborn piglets.
To determine the effect of the hypoxic state of pregnant sows on the immunobiological status of their offspring.
Develop a method for determining the viability of newborn piglets.
Research hypothesis. All processes of the functional system "mother - fetus - newborn" are closely interconnected, interdependent, and the functional state of the maternal organism during pregnancy affects the formation of the immunobiological potential of the offspring.
Scientific novelty. In the presented work, scientific provisions on the relationship and interdependence of functional
mother-fetus and newborn systems. The formation of the immunobiological status in newborn piglets obtained from sows of different parity and with signs of hypoxia in the second half of pregnancy was studied.
For the first time, a new “Method for determining the viability of newborn piglets” has been developed (patent for the invention of the Russian Federation No. 2555550 dated 16.07.2014).
A "Method of preparing a feed mixture for the prevention of malnutrition in piglets during the fetal period" was proposed (application No. The effect of the proposed oxygen feed mixture on the prevention of hypoxic conditions in pregnant sows in the second half of pregnancy was studied.
These developments represent a great theoretical and practical value, because they provide an opportunity for further development research on the problem of increasing the viability of the resulting offspring in farm animals.
Theoretical and practical significance of the work. The results of the performed studies deepen and supplement the information on the formation of the immunobiological status in newborn piglets.
The revealed relationship and interdependence of the immunobiological status with the processes of thermogenesis in newborn piglets expands knowledge about the criterion significance of the thermoregulation system for the newborn organism.
The “Method for determining the viability of newborn piglets” was developed and introduced into veterinary practice to predict their health from the moment of birth, and is also recommended for use in determining the functional state of the body of a newborn animal.
The “Method of preparing a feed mixture for the prevention of malnutrition of piglets during the fetal period” has been developed and tested, which relates to the field of animal husbandry, in particular pig breeding, and concerns the preventive prevention of fetal hypoxia by correcting hypoxic processes in sows during pregnancy.
The assessment of the viability of newborn animals and the method of preparing a feed mixture for the prevention of malnutrition of piglets in the fetal period have been introduced and used in the activities of veterinary and biological specialists, and also serve additional material in scientific and practical activities and for educational process at the Faculty of Veterinary Medicine with a degree in 111801.65 "Veterinary Medicine" and in the direction 111900.62 "Veterinary and Sanitary Expertise" at the Stavropol State Agrarian University (StGAU).
Methodology and research methods. The methodological basis of the research was the following provisions:
- the immunobiological state of the mother's body has a significant impact on the processes of growth and development of the fetus and the formation of the immunobiological potential of the newborn;
- the viability of the offspring depends on the nature and specifics of the interaction in the system "mother - fetus - newborn";
– the level of morphological and functional maturity of a newborn organism is associated with its adaptive potential at the early stages of individual development.
In the course of the work, general methods of scientific knowledge were used: analysis and synthesis, interconnection and interdependence, dynamic development, comparison and generalization; observation, measurement and interpretation; special methods: clinical, hematological, biochemical, immunobiological.
For the processing of experimental data, statistical and mathematical methods of analysis were used to ensure the objectivity and reliability of the results obtained.
The main provisions for defense:
The relationship between the processes of thermoregulation and the immunobiological status of newborn animals has been established, and the level of viability of newborn animals depends on the improvement of thermoregulation processes.
The offspring of sows with an insufficiently perfect thermoregulation system is characterized by signs of reduced viability.
During pregnancy, there is a significant effect of the hypoxic state of pregnant sows on the immunobiological status of their offspring.
Degree of reliability. A significant amount of research has been carried out on a sufficient number of animals using proven methods and using special equipment in certified laboratories. The objectivity of scientific provisions and conclusions is confirmed by the use of biometric processing of experimental data.
Approbation of work. The main provisions of the dissertation work were reported, discussed and received a positive assessment at the 77th, 78th, 79th scientific conferences "Diagnostics, treatment and prevention of diseases of farm animals" by the faculty of the FSBEI HPE "Stavropol State Agrarian University" (Stavropol, 2012– 2015), International Correspondence Scientific and Practical Conference "Science, Education, Society: Problems and Prospects of Development" (Tambov, 2014), International Scientific and Practical Conference "World & Science" ("World and Science", Czech Republic - Brno, 2014), International Scientific and Practical Internet Conference "Innovations and modern technologies V agriculture"(Stavropol, February 4–5, 2015).
The key points of the dissertation were awarded with a diploma of the laureate of the award for supporting talented youth, established by the Decree of the President Russian Federation dated April 6, 2006 No. 325 “On measures state support talented youth"; diploma of the 1st degree in the All-Russian competition for the best scientific work among students, graduate students and young scientists of higher educational institutions Ministry of Agriculture of Russia in the nomination "Veterinary Sciences" and a diploma for II place in the second stage All-Russian competition for the best scientific work among students, graduate students and young scientists of higher educational institutions of the Ministry of Agriculture of Russia in the nomination "Veterinary Sciences" in the North Caucasus Federal District in FSBEI HPE "Dagestan State Agrarian University named after M. M. Dzhambulatov".
Publication of research results. Based on the materials of the dissertation, 13 scientific works, which set out the main provisions of the work performed, including 6 published in periodicals included in the list
leading peer-reviewed scientific journals approved by the Higher Attestation Commission of the Ministry of Education and Science of Russia and recommended for publication of the main scientific results of a dissertation for a degree; received 1 patent.
The structure and scope of the dissertation. The dissertation work is presented on 155 pages of computer text. It consists of an introduction, a literature review, the results of own research, including seven subsections, a conclusion, conclusions, practical suggestions, a list of references and applications. The work is illustrated with 25 tables and 14 figures. The list of used literature contains 279 sources, including 60 foreign authors, the appendix is 17 pages.
Ontogenetic features of the newborn organism of farm animals
The main link between the subsystems of the mother and fetus is the placenta. The maturity and functional activity of the "mother-fetus" system depends on the presence of a full-fledged placenta, as a mutually formed structure that includes the fetal part (fetal vascular membrane) and maternal (uterine mucosa).
The placenta is a provisional organ that functions in strict isolation from other functional systems, provides respiration, metabolism and immune protection in the antenatal period.
Pathological changes in the placenta affect the viability of the offspring, on which the etiopathogenetic predisposition to diseases in postnatal ontogenesis depends.
According to modern concepts, the relationship between the mother's body and the fetus is nothing more than a two-way communication process, in which the "mother - fetus" system forms a functional fetoplacental system.
The composition of this system, in addition to the placenta, also includes the adrenal glands of the mother and fetus, the main function of which is the synthesis of placental steroid hormone precursors; fetal liver and mother's liver involved in the metabolism of placental hormones; the mother's kidneys, which excrete the metabolic products of the placenta.
The main factor that ensures all metabolic processes between mother and fetus is transplacental transfer of substances.
placental dysfunction resulting from various kinds influences, as a rule, lead to the appearance of a whole complex of clinical and morphological disorders, subsequently causing the development of pre-, peri- and postnatal pathology. These disorders affect the functional relationship of the systems of the mother and fetus.
Violation of the functional systems of the mother and fetus is a polyetiological syndrome. According to the results of the research, it was revealed that most of the violations of the relationship of the "mother - fetus" system lead to a change in the development of the placenta, which becomes a trigger mechanism for its destructive changes.
According to a number of authors (V. V. Goryachev, V. V. Rossinovskaya, K. G. Dashukaeva, A. P. Kiryushchenkov, A. P. Milovanov, T. I. Lapina, L. D. Timchenko, V. N Serov, D. S. Charnock-Jones, M. S. Zygmunt) the effect of damaging factors on the formed placenta, cause disturbances with characteristic signs of compensatory reactions.
The studies of B. M. Ventskovsky, S. T. Chernokulsky and others, G. F. Bykova, M. A. Kurtser, S. S. Bolkhovitinova, A. G. Nezhdanov, S. A. Vlasov showed that hypoxia and malnutrition, as the main pathophysiological conditions of the fetus, occurs when the interconnection of functional systems is disturbed during pregnancy. Hypoxia leads to impaired fetal growth and the development of its organs and systems, and malnutrition is a morpho-functional immaturity of the fetus, characterized by a lag in body weight and length of the fetus from the normative indicators corresponding to the gestational age. These processes are becoming one of the main causes of perinatal mortality.
Opinions of scientists 3. A. Akhmedova, R. N. Stepanova, N. E. Kretova, A. I. Arileshere et al. A. P. Kiryushenkova, S. A. Vlasova, V. V. Abramchenko, N. P. Shabanova, D. S. Miller indicate that fetal development disorders are caused by numerous etiological factors.
A variety of options for the manifestation of insufficiency of functional systems for a pregnant woman and fetus depends on the gestational age, strength, duration and nature of the impact of damaging factors, as well as on the stage of development of the fetus and placenta, the degree of severity of the compensatory-adaptive capabilities of the mother-fetus system.
The leading sign of growth retardation and development of the fetus is a violation of the permeability of the placenta. Scientists K. T. Shenzhanov, A. K. Bulashev, E. T. Mikhailenko, L. I. Krivenko and others, V.I. Tsygankov, T. N. Pogorelova, V. I. Orlov et al., A. P. Studentsov, V. S. Shipilov, V. Ya. Nikitin, L. D. Timchenko, V. N. Serov, J. D. Aplin R. V. Anthony, S. W. Limesand et al. , M. S. Zygmunt proved that the permeability of the placenta depends on the structure of its villi, the chemical properties of substances and the magnitude of placental perfusion.
The reports of a number of authors (A. P. Milovanov, O. N. Arzhanova, N. G. Kosheleva and others) established the possibilities of protective and adaptive mechanisms at limiting stress, which does not allow them to be implemented sufficiently for an adequate course of pregnancy and development fetus. This increases the risk of complications for both the fetus and the newborn.
Due to the impact of extreme factors, a violation of the protective function of the placenta is manifested. This function decreases sharply, and the possibility of intrauterine infection of the fetus increases due to the penetration of pathogenic microorganisms into the amniotic cavity.
The severity of placental insufficiency largely depends on the severity of the underlying disease that caused this pathology, as well as on the severity of pathological changes in the placenta.
The results of the assessment of the immunobiological status and the identification of its relationship with the processes of thermogenesis in newborn piglets
The degree of decrease in body temperature in the second group of individuals was the highest and amounted to 2.1 C. In other piglets from the first group, the degree of decrease in body temperature was minimal and did not exceed 0.6 C, while for the first 24 hours of the postnatal period these piglets had an average the value of body temperature was above the average values for the group.
The change in the temperature curve reflects the limiting value of the increase in body temperature. So, for the first group, the specific increase in body temperature was the largest after 2 and 4 hours, which amounted to 0.047 C and 0.053 C, respectively. However, in the second group of animals at the 1st and 4th hour after birth, it had a negative value: -0.011 C and -0.025 C. Therefore, the curve of the specific increase in body temperature, shown in Figure 3, did not settle at a stable level, but tended to increase and decrease.
The body temperature of newborn piglets varied to varying degrees from the initial value. This was expressed by the limits of body temperature fluctuations over the analyzed period of time, which were mostly from the 2nd to the 12th hour in the analyzed groups.
When comparing the parameters of animals according to the limits of body temperature fluctuations, depending on the group affiliation, no significant difference was found (Figure 4).
During the observation period in the first group, the limit of body temperature fluctuations was 1.6 C. However, in peers from the second group, the temperature variability took on the value of 3.3 C. Because of this, the rise in temperature was somewhat delayed in individuals of the second group.
According to the dynamic change in the processes of thermoregulation in 24 hours, a newborn can speak of a more perfect system of thermoregulation in the first group of piglets relative to the second, where the formation of thermogenesis was delayed and less effective.
The results of birth weight and metabolic potential of piglets are presented in Table 3. Table 3 - Metabolic potential of piglets
At birth, newborn piglets had differences in live weight depending on group affiliation. The change in body weight for the specified period also had an unequal level for the indicated groups. In the first group, body weight after birth was 1.37 kg, and after 24 hours it was 1.42 kg. At the same time, in individuals of the second group, a decrease in body weight from the initial 1.09 kg was observed, and at the daily age it was 0.95 kg.
In the second group of piglets, the metabolic rate was lower than the first group by 0.15. The data obtained prove that in the second group there was heterogeneity in terms of the level of morphofunctional development of piglets.
Based on the studied dynamics of thermoregulatory processes after birth, it can be concluded that individuals of the first group have the most pronounced adaptive potential. The fact that at the time of birth the thermoregulatory processes in animals were at various levels maturity, and caused a different metabolic rate in piglets on the first day.
The immunobiological status of the analyzed offspring was taken into account according to the following parameters: the relative content of T- and B-lymphocytes, the level of immunoglobulins (A, G, M), the functional activity of neutrophils - the percentage of phagocytic activity of neutrophils (PAN%), phagocytic number (PF), phagocytic index (FI), phagocytic capacity of blood (FEK%), bactericidal and lysozyme activity of blood serum (BASK% and LASK%) presented in Table 4.
The main differences in the parameters of the immunobiological status between the established groups were expressed in the low content of T-lymphocytes from 14.6±1.45% to 19.8±1.60% in the second group in relation to their peers, in whom this value was from 17 .4±0.14% to 24.9±0.60%, the differences were 16.1% and 25.8%, respectively. According to the results of the determination of B-lymphocytes, it can be seen that their content in individuals with less perfect thermoregulation (group 2) was reduced by 21.4, 25.5 and 36.4% over the established period compared with similar indicators.
By the age of 30 days, in piglets with signs of reduced thermogenesis, the level of T-lymphocytes was two times lower than normal, and reduced relative to the 1st group, which caused T-cell immunodeficiency with activation of the B-cell immunity.
The indicators of the humoral link of immunity (Ig A, G, M) in piglets from the 1st group gradually increased over the entire period, however, in the 2nd group, the levels of Ig A, Ig G, Ig M lagged noticeably behind their peers. Thus, the former showed a significant increase in the concentration of Ig A, Ig G, Ig M by 49.1%, 31.9%, 54.3%, which is associated with the activation of local humoral immunity, while in individuals with a less perfect thermoregulatory function, levels immunoglobulins were deficient.
Indicators of the functional activity of neutrophils (FI, PF, FEK) before the age of one month in piglets of the first group were significantly higher (p 0.05), namely, the phagocytic activity of neutrophils by 29.8%, the phagocytic index -38.1%, the phagocytic number - 31.1%, phagocytic capacity - 24.1%. There were also significant differences in the analyzed groups in bactericidal and lysozyme activity of blood serum by 25.2% and 32.9%, respectively.
As a result of the studies in the first and second groups of piglets, a positive correlation was noted (table 5) between indicators of the perfection of thermoregulatory processes (specific increase in body temperature in 24 hours (T) and concentrations of immunoglobulins (classes A, G, M), the amount of T- and B-lymphocytes, phagocytic activity of neutrophils, bactericidal and lysozyme activity of blood serum for the periods of determination.
Determination of the hypoxic state of sows during pregnancy
The alkaline reserve of blood was characterized by a change, but to a greater extent there was a decrease in the reserve alkalinity, which in piglets decreased by 24.7% from the initial value (on the first day after birth). When determining the total protein, it was observed to decrease over the period of the study in the blood serum of piglets by 12.7%.
The level of calcium and phosphorus in piglets was in the lower limits of physiological fluctuations. So, on the 1st day of the study, there was a tendency for their level to decrease to values of 2.14±0.13 and 1.23±0.10 mmol/l, respectively.
An increase in the amount of magnesium in the blood serum to a large extent up to 1.01±0.10 mmol/l is associated with the state of hypoxia and acidosis in the newborn. The presence of oxygen deficiency in piglets from the experimental groups was indicated by a high content of lactic acid and the concentration of ketone bodies in the blood by 25.6% and 34.7% higher than the initial value. Thus, an increase in the content of magnesium, an increase in the content of lactic acid and the concentration of ketone bodies create conditions for the flow oxidative reactions by an acidosis-dependent mechanism.
At the same time, in the blood of experimental animals, there was a change in hematological parameters and non-specific resistance (Table 16).
So, the absolute number of erythrocytes was on the 1st day -3.38±0.Cx10 /l, on the 5th day - 3.06±0.09x10 /l and on the 10th day 2.71±0.24x10 /l, this caused their decrease by 10.5% and 24.7%. A decrease in this amount indicates a decrease in oxygen consumption by body tissues and shows the low efficiency of metabolic processes in the body of piglets. Also, confirmation of the negative effect can be traced by a decrease in hemoglobin by 18.5% in the first 10 days of the newborn.
The hypoxic state in newborn animals induces a decrease in the activity of the main links of natural resistance in these individuals. Thus, this condition causes a low percentage of phagocytic activity of neutrophils, which did not exceed 24.34±1.20% in the first 10 days of postnatal development. At the same time, the bactericidal activity of the blood serum did not exceed 20.33±0.96%, and the lysozyme activity did not exceed 20.67±1.92%, respectively. The established values were at a low physiological level with a pronounced deficient effect. From the studies carried out, it can be assumed that the hypoxic state of the maternal organism leads to significant changes immunobiological status of their offspring. This implies the importance of the problem of prevention and correction of this negative impact in the biological complex "mother - fetus - newborn". This condition is a necessary link for maintaining high productivity, fertility and obtaining a viable offspring.
In order to prevent a hypoxic state in the second half of pregnancy, we have proposed a method for preparing an oxygen feed mixture to correct this pathogenetic effect on functional system"mother - fetus - newborn".
To establish the effect of feeding an oxygen feed mixture, 4 groups of pregnant sows of a large white breed were formed, 5 animals each with signs of hypoxia - three experimental groups and one control group. Sows of the first received 60 days before farrowing in addition to the main diet, once a day before morning feeding, an oxygen feed mixture in the amount of 150 g/animal according to the first recipe, the second group - 300 g/head. according to the second prescription, and the third group - 450 g / goal. for the third prescription. The fourth group served as a control and received the main diet without the use of an oxygen feed mixture. The duration of the application of the proposed mixture was 60 days.
Preparation and feeding of oxygen feed mixture For the first example of preparation, oatmeal (70 g) was mixed with rosehip syrup (30 g), which was used as a taste corrector, a source of microelements and multivitamins, a tonic and hemoglobin-enhancing substance. The foaming agent was a solution of 8% gelatin (20 g), previously dissolved in water at 80 ° C, while the mixture was kept for at least 10 minutes before saturation with oxygen. Bringing the volume of the mixture to 150 g was carried out by adding 30 g drinking water. Saturation of the feed mixture with oxygen was carried out by mixing it, and then a constant gas flow of oxygen was passed through the resulting composition for 2-2.5 minutes at a pressure of 0.5-0.7 (2.04-7.14) MPa (kgf / cm ) until a stable oxygen-containing foam is obtained. The foam was kept for 15 minutes.
According to the second example, the oxygen mixture was prepared in the same way as in the first method, but the following quantities of components were used: oatmeal - 150 g, rosehip syrup - 80 g, 8% gelatin solution - 70 g, water - 50 g. the same parameters, however, stable oxygen foam was maintained for 40 minutes.
According to the third example, the preparation of the mixture was carried out in the same way as in the first example, with the following proportions of ingredients: oatmeal - 220 g, rosehip syrup - 80 g, a solution of 8% gelatin - 70 g, water - 50 g. identical parameters, but stable oxygen foam was maintained for 20 minutes.
To prepare one portion of the mixture, 10.53 cm3 of oxygen was required. The prepared mixture is a foamy-liquid composition of light brown color with a sweet smell.
It was found that when the diet of experimental sows was given an oxygen feed mixture in the second half of pregnancy, their appetite significantly improved and acid-base balance indicators increased with the normalization of natural resistance parameters to standard values, eliminating the hypoxic-acidotic phenomenon and presented in (Table 18).
The dependence of the viability of piglets on the perfection of the processes of thermoregulation and the level of metabolism on the first day after birth
To determine the viability of newborn piglets, the developed method includes: measuring the dynamic change in body temperature immediately after birth, after 1, 2, 4, 6, 12, 24 hours and live weight at birth and after 24 hours.
The tested method allows assessing the perfection of thermoregulatory processes by comparing changes in body temperature in a particular individual with the average data for the group in the first day of life. The dynamic characteristic of the temperature response, by analogy with body weight, reflects the adaptive and metabolic potential of the newborn, which makes it possible to predict the level of risk of further development and its viability.
The informativeness of the proposed method is explained by the fact that in this case there is a sign of a dynamic characteristic, which makes it possible to identify the safety margin of the newborn organism and judge the ability to maintain a relative constancy of homeostasis. The level of perfection of thermogenesis processes was used as an integral indicator at the organismal level.
Our approach to predicting viability based on dynamic changes in body temperature reflects the integral level of energy processes in a newborn immediately after birth. For this, the viability index is used, which is calculated by the ratio of the indicators of a particular individual to the average values for a group of animals using the developed formulas.
It was revealed that in individuals that did not have significant fluctuations in body temperature, the appearance of a confident standing posture and a sucking reflex in newborn piglets was realized earlier.
During the mentioned period of observation, the group of piglets classified as viable with IL 2 in terms of absolute gain, average daily weight gain was significantly higher by 40.1% and 35.6% than the group of low-viable individuals with IL 2. Moreover, the safety in the group of viable individuals with IL 2 was 100% , morbidity - 14.2%, while in analogues the safety was only 28.6%, morbidity - 85.1%, and mortality - 71.4%. The results of the lethal outcome confirm the criterion significance of the proposed viability index for newborn animals.
Thus, it can be argued that the dynamic characteristic of the temperature reaction and body weight of the newborn can act as the most significant indicators to assess the viability of a given organism. At the same time, these indicators reflect the adaptive and metabolic potential of the newborn, which makes it possible to predict the level of risk of further development.
The discrepancy between the level of adaptive-compensatory capabilities and functional loads on the pregnant body is the main predisposing link in comorbidity.
One of the main causes of diseases in a newborn is the transferred hypoxic state during the fetal period of development.
Under conditions of altered homeostasis, the mother's body reduces the transport of oxygen and nutrients to the fetus. It was established by K. G. Dashukaeva, A. G. Nezhdanov, Yu. N. Fedorov, O. A. Verkhovsky, M. A. Kostyna that a normal birth depends on the state of the regulatory mechanisms during pregnancy. The formation and development of the placenta is disrupted, which leads to biochemical, enzymatic and morphological changes in unified system“mother - placenta - fetus” (F. P. Petryankin, L. I. Chekasina).
The direct result of hypoxic exposure is the development of placental insufficiency in pregnant women, which reduces the adaptive capabilities of the offspring and may cause their death in the early peri- and postnatal periods (Yu. And Savchenkov, S. M. Suleimanov, N. N. Slobodyanik).
According to I. M. Karput, M. A. Sidorov, Yu. N. Fedorov, O. M. Savich, A. F. Dmitriev, the most important mechanism for full adaptation to environmental conditions is immunobiological reactivity. The hypoxic state of a pregnant woman is one of the main reasons for the decrease in the natural, cellular and humoral immunity in born offspring.
According to the studies of K. U. Suleimanov, A. I. Kuznetsov, G. V. Gudkov, a hypoxic state accompanies any pathology. This is what determined the scientific interest in the problem of correcting this pathogenetic effect in a pregnant organism.
From the results of the studies, it can be concluded that the hypoxic state of the maternal organism leads to significant changes in the immunobiological status of the offspring obtained from them.
The level of physical development of newborn piglets, depending on the presence of signs of hypoxia, differed significantly in all assessed indicators (metabolic coefficient). Deficiency of physical development was noted in piglets that underwent antenatal hypoxia.
Thus, it has been established that the quality of offspring obtained from sows with signs of hypoxia in the second half of pregnancy indicates a direct or indirect effect of this pathogenetic effect on the fetoplacental complex.
From a biological point of view, newborns of all types of farm animals are fruits that have not completed the full cycle of physiological maturation, that have fallen into completely new conditions, to which their body must adapt in a short period of time. In the womb, the fetus was connected to the external environment only through the amniotic fluid and the mother's circulatory system. The external environment for him was the mother's body. The organs of the fetus, and especially the immune system, in the new conditions require special training during the period of adaptation, and only in the process of this training do they begin to manifest their inherent physiological functions.
Newborn animals (calves, lambs, kids, piglets, foals) differ from the body of adult animals of the corresponding species in a number of physiological features.
From a completely sterile environment, the fruits fall into external environment with the prevailing microbial landscape and climatic conditions. He must adapt to these new conditions as quickly as possible. But in a newborn, the type of nutrition, respiration and blood circulation has changed, because. his connection with his mother through the placenta was severed.
In the blood of newborns there are no gamma globulins (immunoglobulins) - the main proteins that perform a protective function against microbial attack, and their own cellular immunity factors are in a state of formation and maturation. The only source of protection in the first days of life for a new organism is maternal colostrum, the quantity, quality and timeliness of which depends on the level of resistance of the organism. The penetration of maternal (colostrum) protective proteins into the blood of newborns is provided by immature epithelial cells lining the small intestine. After saturation of the blood of the newborn with colostral immunoglobulins, the immature epithelium is replaced by an impermeable, mature epithelium capable of performing and sustaining the digestive function of the intestine. Consequently, between the mother's body and the newborn is established new connection- not through the placenta with its placental barrier, as it was during fetal development, but through the mammary gland with a completely unique product produced in it - colostrum, which contains a complete set of biological components that ensure the preservation of life in the first days after birth. Without this new functioning connection, the newborn is doomed.
The open cavities of the body of the born fetus are sterile and they are still in the process of childbirth, and then, after leaving the mother's womb, they are populated by microorganisms of the external environment. If the newborn does not receive maternal colostrum with the most important protective factors contained in it within the first 2 hours, then the microflora that has entered, mainly gram-negative, toxigenic, will cause inflammation of the mucous membrane of the stomach and intestines.
During the neonatal period, normobiosis is not formed in the intestine, the settlement and formation of normal microflora, one of essential functions which is to provide colonization resistance™. Colonization resistance is a set of mechanisms that give stability to the composition of normal microflora and prevent colonization of the intestines of the host organism by an excessive amount of putrefactive and toxigenic microbes. Normal intestinal microflora is involved in water-salt metabolism, in the regulation of the gas composition of open cavities of the body, has a pronounced detoxifying effect, promotes the metabolism of proteins, lipids, carbohydrates and nucleic acids, performing a mutagenic and antimutagenic function, etc. As a result of the action of lysozyme, a stimulator of immune system cells, muramyl dipeptide, is formed from cells of normal microflora.
The normal resident intestinal microflora includes bifidobacteria of various species, lactobacilli, enterococci, lactic acid streptococci, actoroids, Escherichia in a certain ratio, yeast-like fungi, etc. In healthy animals, up to 80-90% of the hormonal microflora are bifidobacteria, lactobacilli and other lactic acid microflora. Normally, 1 g of the content of the large intestine of animals and humans contains 108-1012 bifidobacteria, and their decrease to 107 indicates a violation of microbiocenosis. The antagonistic activity of bifidobacteria to putrefactive and pathogenic microbes is ensured by their high adhesiveness on intestinal enterocytes, the production of bactericidal substances and immunomodulators. In addition, these microorganisms provide 40% of the body's need for essential amino acids: lysine, arginine, glutamic acid, valine, leucine, tyrosine, as well as vitamins B, C, K, nicotinic and folic acids.
The second important representative of the normal intestinal microflora are various types of lactobacilli. Their antagonistic activity is associated with high adhesiveness and the production of interferons, immunomodulators and bactericidal compounds (lactacins, lactobiotics, etc.). The amount of lactobacilli is normally up to 108 cells per 1 g of feces.
Normally, 1 g of feces contains enterococci and bacteroids up to 108, Escherichia - up to 109, fungi of the genus Candida and Clostridia - up to 104.
If the ratio of these microorganisms is violated in the direction of reducing the content of lactic acid microflora, dysbacteriosis and disease develop, especially in newborns who have not received colostrum.
The source of lactic acid microflora is fresh vegetation in the flowering stage, as well as hay. good quality. In practical terms, some animal species are deprived of this most important source of representatives of normal microflora.
For the directed and faster formation of normal microflora in newborns, along with the timely feeding of maternal colostrum, it is advisable to use early probiotic preparations containing live lactic acid bacteria - bifidobacteria, lactobacilli, lactococci. Herbal flour, hay infusion, which contain lactic acid microorganisms, are also useful.
In the organization of highly profitable animal husbandry with the production of high-quality products and the preservation of the environment, deep scientific approach to solving problems on the basis of general biological laws of growth and development of the animal organism. The practice of animal husbandry shows that one of the most important problems in increasing the profitability of the industry is to preserve and increase the viability of newborns and the newborn period of animals. In the prenatal period, as a result of disorders that occur in the "mother - placenta - fetus" system, animals are born with an unequal morphofunctional status of the body. This leads to the fact that a significant number of them are underdeveloped, which many clinical researchers define as malnutrition, taking into account only their live weight. It should be noted that in Lately, as a result of changes in the prenatal growth and development of animals, the average indicators of their live weight and the morphofunctional status of the body have significantly decreased in almost all species and breeds.
However, the division of newborn animals into normotrophic and hypotrophic is not always a reliable criterion of their viability, which to a large extent negatively affects the conservation, and further reduces the implementation of genetically incorporated productivity. Despite this condition, at present there are still no sufficiently complete informative criteria for determining the morphofunctional status of the body, individual apparatuses, systems and organs in newborns and the newborn period of animals, which is especially important in the occurrence and course of certain diseases.
In the scientific literature there are conflicting data on the physiological state of newborns and the composition of their blood. In addition, most studies aimed at developing therapeutic measures for sick animals do not take into account the characteristics of the newborn organism and its adaptive capabilities of the intensity of transformation during the neonatal period. In scientific publications and reference books, disorders that occur in the body of animals of the neonatal period are combined into general concept- diseases of the young. Only recently met individual works, in which diseases of the newborn and the neonatal period are distinguished into a separate group called “Neonatal diseases”.
The absence of criteria for determining the morphological and functional characteristics of newborns and the neonatal period of animals significantly complicates not only the diagnosis, but also the treatment and prevention of diseases characteristic of this age. Without certain morphological and physiological features of the organism, it is not possible to develop a technology for feeding and keeping newborn animals, which leads to a significant decrease in their viability against the background of prenatal underdevelopment.
The analysis of scientific literature and studies conducted on the basis of the scientific problem laboratory of veterinary neonatology of animals of the Southern Branch "Crimean Agrotechnological University" of the National Agrarian University show that the structural and functional state of the body, individual organs of the diurnal and newborn period of animals is not the same.
newborns Productive animals that belong to maturonate (mature) are animals Daily age. They are characterized by manifestations of some congenital reflexes immediately after birth. Statolo-locomotor acts appear 15-20 minutes after birth, and the sucking reflex - after 30 minutes. Remains of a mucus-like liquid are found in the conductive tracts of the respiratory organs. In the lungs, especially the cranial parts, atelectasis particles (acini that have not yet received air) are determined.
Morphological changes in the blood of newborn animals are due to the cessation of placental circulation. The pulmonary circulation (external type of breathing) immediately begins and, as a result, the inclusion, as a result, in intensive work between the atria of the pulmonary circulation and the closure of the foramen ovale, the desolation of the arterial duct, which connects the trunk of the pulmonary arteries with the aorta, which ensures the flow of blood into the general circulation in the fetus.
In the liver, both instantaneous and gradual changes in blood flow occur. The blood flow through the umbilical vein instantly stops, as a result of impaired placental circulation. Blood enters the liver, or rather, its umbilical-gate collector, only through the portal vein, which drains the latter from the stomach and intestines. However, the umbilical-gate collector still anastomoses through the ductus venosus with the caudal vena cava.
The first feeding of a newborn animal causes intensive blood circulation in the digestive organs, which determines a more active blood flow through the portal vein of the liver. In addition, the liver parenchyma is still immature and cannot fully perform the digestive function. Therefore, most of the blood through the umbilical-gate collector enters the venous duct, and through it, directly into the caudal vena cava. It should be noted that the fruits left side The liver is supplied with blood more by the umbilical vein, the right one by the portal vein, and the stromal structures of the entire organ by the hepatic artery. In newborns (daily), as well as adult animals, the portal vein is the main source of blood supply to all parts of the liver. Characteristically, the structure of the liver is affected both by the peculiarity of its blood supply, and by the maturation of animals and the peculiarities of prenatal development. In underdeveloped productive animals, despite the general patterns of afferent and efferent circulation, the typical structure of the liver parenchyma is not determined. The chaotic distribution of hepatocytes and the presence of scattered hematopoietic islands is evidence of the failure of the liver to perform an antitoxic function, which is determined by the portal circulation (see section 3.5.1.3.1.1).
The caudal (large) intestine contains meconium, which, after the first feeding with colostrum, is released into the external environment.
In the organs of hematopoiesis and immunogenesis (bone organs, thymus, spleen, lymph nodes and lymphoid tissue associated with mucous membranes), parenchymal structures are detected against the background of the formation of microenvironment components, which is evidence of their incompleteness and failure to fully adequate response to foreign stimuli.
Newborn (daily) productive animals are characterized by crumb pads on the soles of the hooves, as well as the still “wet” umbilical cord.
Stato-locomotor movements of newborns are uncertain, limbs tremble, movements are not coordinated. Day old animals get tired quickly. However, they are already able to actively move until the end of the day.
In the blood of daily animals, the number of erythrocytes predominates, there are much fewer leukocytes and especially lymphocytes, compared with older animals. Up to 80% of hemoglobin is fetal. Proteins contain a very small amount of immunoglobulins.
Against the background of cardinal changes in the sources of gas exchange and digestion, osteogenesis of the main (diaphyseal) and epiphyseal centers of ossification, morphogenesis of hematopoietic organs and immunogenesis, the presence of a secretory apparatus and microvilli in the mucous membrane, which ensure the consumption of colostrum, in daily productive animals, only structures characteristic of prenatal period of ontogeny. This requires considerable attention on the part of the attendants to comply with certain norms for feeding and rearing newborn animals, according to the biological needs of their body. In addition, the rapid entry of the body into a far unstable external environment, large energy losses at birth, cause an extreme situation for the body of newborns.
Therefore, it must be remembered that in connection with the transition to a new environment of existence and violation of the regimen and technological methods of feeding, the body of newborn productive animals may not respond adequately to feeding with colostrum.
neonatal period It is, as I. A. Arshavsky points out, very important, but it is not defined in time, and for each species of animal it lasts differently. However, this period is of great importance for their subsequent existence and for the implementation genetic possibilities and not only productivity, but also viability. Animals of the neonatal period, first of all, along with an inadequate response of their body to adverse environmental factors, have great opportunities for adaptogenesis. During the neonatal period, almost all innate reflexes are realized and conditional on the source of food, feeding regimen, place of detention and auditory, visual signals are developed, stato-locomotor acts are activated. The crumb pads on the hooves quickly disappear, on the plantar surface of which a white line (leaflet horn of the wall) is determined, the finger pulp is released. The stump of the umbilical cord falls off.
Between the atria, the foramen ovale is completely overgrown. The ductus arteriosus has a small, slit-like opening that prevents blood from flowing through it. In the lungs, islets of acini atelectasis completely disappear. Significant changes take place in the liver. As a result of the active function of the intestine, hormones and active substances enter the portal vein, which affect the hemodynamics and structure of the liver parenchyma.
In piglets, the anastomoses between the umbilical-gateway collector and the caudal vena cava are completely closed (overgrown). The miraculous network of the liver is included in the work, which indicates its active antitoxic function.
In calves, the venous duct between the umbilical-portal collector and the caudal vena cava still remains in the form of a slit-like opening, which indicates the possibility of blood flow through it and, if digestion is disturbed, contributes to intoxication of the body. In the parenchyma of the liver of pigs, islands of hematopoiesis disappear. Hepatocytes take on a beam structure around the central vein, which provides the formation of hepatic lobules. The digestive organs begin to gradually adapt to the consumption of not only colostrum (milk), but also the feed characteristic of this type of animal.
In calves, the neonatal period lasts 10-14 days and coincides with the beginning of the functioning of the rumen and the possibility of consuming roughage. In piglets, this period coincides with the ability of the gastric mucosa to secrete hydrochloric acid and perform not only the function of accumulation, but also digestion, which is fully manifested at 20-21 days of age.
One of the criteria for the neonatal period of productive animals is the characteristic and intense transformation of morphoembryonic structures into structures that correspond to the realization of the genotype and the reaction to the action of external environmental factors. As a result, there is a significant destruction of prenatal structures along with the formation of new ones, which requires a significant amount of energy and plastic material. The required amount of energy, for the most part, is formed as a result of biomechanical loads that occur during the active movement of newborns. plastic material comes with colostrum.
In the neonatal period, mainly qualitative changes take place in the body of productive animals. The studies conducted by the authors of the monograph found that in bone organs that perform the function of universal hemoimmunopoiesis, not only the area of their ossification centers increases due to apophyseal foci, but also intensive transformations of primary spongy bone tissue into secondary lamellar tissue occur, predetermining an increase in the area of red bone marrow . The area of cartilage tissue is significantly reduced against the background of an increase in bone tissue. In the tubular bones, the red bone marrow turns into yellow, which indicates a qualitative change in its hemoimmunopoietic functions.
In the neonatal period, due to restructuring, the absolute mass of the thymus increases, as does the area of the cortical zone of the lobules. In the brain zone, the number of thymic bodies increases. Layers of loose connective tissue of thymus lobules contain only single fat cells. It is characteristic that in the peripheral lymphoid organs (spleen and, especially, visceral lymph nodes), a significant number of lymphoid nodules with reproduction centers are formed, which is evidence of the ability to give an appropriate reaction to the antigen.
Against the background of minor changes in the mass and size of the stomach and intestines, lymphoid structures develop in their mucous membrane, which provide immune protection against the action of antigenic factors.
Thus, in productive animals in the neonatal period, the structural and functional formation of the organs of the immune system takes place, which ensures their viability in the environment.
In animals with prenatal underdevelopment, the neonatal period lasts longer. A characteristic manifestation of this is not only the disease of animals, but also their significant lag in growth and development. At the same time, the organs of universal hematopoiesis contain a significant amount of cartilaginous tissue and osteoblastic bone marrow against the background of a decrease in the mass and size of individual bone organs, as well as the formation of additional centers ossification. The formation of the hematopoietic function of bone organs is delayed, which is manifested in a decrease in hematological parameters, especially cellular structures and hemoglobin. Not only adaptive changes in the structures of bone organs are disturbed, but also metabolism. Under-oxidized products accumulate in the body, negatively affecting the entire body.
In the thymus, there is a decrease in the area of the cortical zone with a slight increase in its size. In the spleen and lymph nodes, lymphoid formations associated with the mucous membranes of the tubular organs, the formation of lymphoid nodules is delayed, especially with reproduction centers, which may be the main factor in reducing the viability of newborn animals. The underdevelopment of animals in the neonatal period, especially of the immune defense organs, predetermines the second wave of the occurrence of diseases and dysfunctions of the digestive organs. Recently, the delay in adaptive transformations in the newborn period of animals is manifested by a violation of the function of the respiratory organs. As a result, on the basis of atelectasis islets, bronchopneumonia occurs, primarily affecting the cranial parts of the lungs.
So for Newborns ( Diurnal) animals are characteristic not only external signs, but also significant hemodynamic changes in blood circulation.
Animals neonatal period Almost all unconditioned reflexes are included in the work and up to 90% of conditioned ones are developed. At the tissue level, there is an intensive replacement of intrauterine structures with functional ones. In calves, the neonatal period lasts until the beginning of the functioning of the rumen (12-14 days), in piglets - until the appearance of hydrochloric acid in the stomach (15-21 days). The criteria for the morphological features of newborns and the neonatal period of animals make it possible to determine their prenatal development and the nature of adaptive changes as a result of the transformation of morphoembryonic structures into morphofunctional ones, which is of practical importance in correcting the technology of their feeding and rearing in order to increase viability, as well as timely disease prevention. As a result of the replacement of fetal cell structures, their number in the blood decreases somewhat, stabilizing until the end of the neonatal period. In the blood serum, the amount of immunoglobulins increases significantly, which indicates the formation of the body's immune reactivity. The work of the heart acquires a definitive character, the centers of thermoregulation acquire a certain stable function, which leads to the formation of a constant body temperature.
1. The role of the postnatal period in the life of an animal. The early postnatal (aka neonatal, or neonatal period) period is of exceptional importance for the life of an individual, because. at this stage of development, the most important relationships of the organism with the environment are formed, connections are established with the vital components of this environment, and the foundations of the behavior of an adult animal are laid.
This period of development is typical for immature young and chicks of nestling birds, which are born blind, deaf and helpless. During the postnatal period, the most significant changes occur in the development of the cub. From a completely helpless embryo, he turns into an animal, more or less capable of independent existence. Mature-born cubs spend this period in the womb.
2. Some physiological features newborns. In the first minutes after birth, the respiratory center turns on, which regulates the supply of oxygen to the body and the removal of carbon dioxide until the end of life, and with the first breath, the lungs straighten out. Intensively licking the newborn, the female helps the cub take the first breath and helps restore the tone of the blood vessels.
During the first weeks, the cubs are not able to maintain a constant body temperature. The necessary body temperature of the cubs is provided by the mother, warming them with her body. Leaving the nest, the female covers the cubs with nesting material or closes the entrance to the hole. In the absence of the female, the cubs crawl into a compact pile, which helps them to keep warm. This is the so-called crowding reaction. Parents of chicks keep their chicks warm all the time. At the same time, they regularly replace each other, while one of them feeds himself and gets food for voracious chicks. In some species, only one parent warms the chicks, then the second provides food for him.
The baby of a mammal receives all the energy necessary for growth and development with mother's milk. In accordance with this, his digestive system produces during this period only the enzymes that are necessary for its digestion. When suckling, the cub pulls the nipple with frequent short movements of the head and rhythmically massages the mammary glands with its paws, which in combination contributes to the separation of milk.
Newborn babies are not able to urinate and defecate on their own. The mother licks the cubs, thus massaging the sphincters, and eats all their secretions. In the absence of this behavioral feature, unsanitary conditions would quickly arise in the nest, and, thus, it is always clean and dry in it.
A similar adaptation exists in nestling birds. The feces of chicks during the nesting period are enclosed in a dense mucous capsule, which the parents remove from the nest.
In young mammals during this period, there is no daily rhythm of sleep and wakefulness, characteristic of adults, associated with the alternation of day and night. In newborns, periods of sleep are evenly interspersed with periods of wakefulness, i.e. sucking. Some differentiation of the periods of day and night appears only towards the end of the period, when the cub's eyes are well erupted and it gradually begins to emerge from the dark lair.
Huge changes after birth occur in the nervous system. So, the brain of a newborn puppy is no more than 12 percent of the mass of the brain. adult dog. It grows intensively and by the end of the second month of the puppy reaches three quarters, and by the end of the sixth month - almost the full mass of the brain of an adult dog. The brain of a newborn puppy is also different in its development. By the time of birth, those areas of the central nervous system are best developed that provide the regulation of the functions necessary for its existence: digestion, respiration and sucking. The cerebral cortex of a newborn puppy already has well-developed main convolutions. However, nerve cells (neurons) in the first days after birth are still very immature.
3. Development of newborn behavior.
Mammals. By the time of birth, the olfactory, gustatory, skin-temperature and vestibular analyzers function in the cub. The first behavioral response a newborn exhibits is a positive response to a warm, furry surface. This reaction persists throughout the neonatal period and contributes to the formation of the crowding reaction. A newly born baby, while still connected by the umbilical cord to the placenta, is already starting its way to the nipples and, having reached them, begins to suck. This innate food reaction in the very first hours after birth, like a snowball, is overgrown with conditioned reflex reactions. Gradually, the puppy's movements improve, he learns to find the most milky nipples, recognizes the smell of his mother.
Primate cubs are characterized by a grasping reflex, which manifests itself in a reflex grip of the hand. It helps to keep the cub on the mother's body. The same reflex is noted in newborns. The search for a nipple in primates is expressed in an instant turn of the head with an open mouth when a warm object is touched to the cub's face. This reaction can also be observed in newborns.
Thus, the first period of the life of a newborn cub is characterized primarily by rapid growth and improvement of unconditional reflex reactions. By the end of it, the cubs begin to walk, their eyes open. Behavior improves - games begin, defensive reactions arise. The duration of this period can be different, for example, in predators of the canine family, it lasts 18-20 days, in small rodents 8-10, and in large primates 3-4 months.
Birds. The behavior of chicks of chicks also develops in a similar way. The first reaction of the chick after hatching in response to any touch is to stretch the neck and open the mouth wide. This reaction is similar to the search for the nipple in mammals. During the first few days, it manifests itself in almost any stimulus. As the auditory analyzer develops, the chicks begin to respond to a certain stimulus: a slight shaking of the edge of the nest at the time of the arrival of an adult bird, the touch of the bird's paws on the hole in the hollow, a specific acoustic "food signal" of the parent, etc. After the chicks open their eyes, they begin to respond to visual signals. For example, the shading of the opening of the notch by a arrived adult bird or its silhouette on the edge of the nest. A stronger than usual shaking of the nest or an unusual sound causes the chicks to develop a defensive reaction of hiding. The feeding behavior of the chicks also becomes more complicated: it becomes orderly. Arriving with food adult bird descends to a strictly defined point of the edge of the nest and lowers the food into the wide-open mouth of the nestling located in a strictly defined zone of the nest. After that, the bird takes a capsule with feces from the chick that it fed on the last arrival, and flies away with it. However, despite this behavior, all the chicks are fed and cleaned. This is possible due to the constant cyclical movement of the chicks in the nest. After feeding, the chick moves in a certain direction, giving way to the next one. In this case, all the chicks in the nest make the movement in a circle. A full cycle of movements - from the zone with the maximum probability of getting food, through all subsequent ones again to this zone, takes an average of 40-50 minutes. It is thanks to this cyclical activity that the hungriest chick once again receives food.
Such an idyllic picture is not observed in all species. In some birds, there is fierce competition between chicks, which leads to partial death of the brood.
By the end of the chicks' stay in the nest, they are overgrown with feathers, their sensory systems finally mature. Soon they leave the nest and turn into so-called fledglings, which their parents continue to feed for some time.
Mixed feeding period
The second period should be considered as a transition period. Its beginning marks the emergence of interest in the food that adult animals consume. This interest arises when the enzymes necessary for the digestion of adult food appear in the digestive system and teeth begin to erupt. At the same time, chewing movements appear in the cub - until now, only sucking has been the answer to any irritation of the oral cavity. In young primates, grasping movements of the forelimbs are activated; everything they manage to grab, they taste. Similar behavior is observed in children.
At this time, some parents begin to bring solid food to the cubs. However, despite the progress of development, the cubs continue to consume mother's milk and be under the care of their parents.
The transition from milk feeding to mixed nutrition occurs at a time when the olfactory, auditory, and visual analyzers of the cub are already sufficiently mature for the perception and differentiation of objects of the external world and the formation of numerous conditioned reflexes. First of all, food conditioned reflexes are formed in him, which provide a full-fledged act of nutrition while the cub is still in the nest.
With the improvement of movements, he begins to separate from his mother and brothers, leave the nest, explore the surrounding space. At this time, innate orienting reactions are actively manifested in the cub, conditioned defensive reflexes begin to form. From the moment of the first exits from the nest, he enters into new phase of its development. A lot of new impressions fall upon him, he must learn to navigate in the world around him, gradually understand what to be afraid of and what not. The farther the calf moves away from the nest, the more often it has to deal with other representatives of its own and other species. In short, he enters the community and must master the laws that exist in it. During this period, the cubs can already develop conditioned reflexes to any signals of the external and internal environment, but the rate of their formation is still low.
The duration of this period also varies greatly among representatives of different species.
In nestling birds, this period corresponds to the time when the parents still continue to patronize and feed the chicks that have flown out of the nests.
In fact, it is from this period of ontogeny that the life of brood birds and mature mammals begins.
Period of socialization
As it develops, the growing cub begins to contact more and more with other family members, and when leaving the nest, with other animals. This period is of particular importance for species that maintain family relationships for quite a long time.
In puppies of domestic dogs and other canines, this period begins when they reach about a month of age. By this time, the basic physiological functions have been formed, but the intensive growth of the animal and milk feeding continue. During this period, the puppy's nervous system is most susceptible to the influences of both favorable and unfavorable environmental influences. The motor activity of puppies increases sharply. A daily rhythm of motor activity characteristic of the species is formed. Conditioned reflexes in puppies of this period of development, as mentioned above, are developed instantly, but are not stored in their memory for long. Therefore, it is too early to start engaging in serious training at this age.
As puppies become more active, so does the amount of environmental stimuli they are exposed to. In this regard, the research activity of puppies is also sharply increased. They have an orienting-exploratory reflex, called I.P. Pavlov "What is it?", reaching the greatest intensity during this period of ontogenesis. Puppies are alert, raise their ears, head under the action of any irritants, approach them, lick, take them in their mouths, gnaw. Manipulation with surrounding objects is the most important condition for further improvement of various skills. Motor exercises have a beneficial effect on the development of the organs of movement and on the functioning of the heart, lungs, and brain of animals. For normal development, the cub needs to receive as much information as possible and meet with all sorts of diverse environments. Restriction of movements and various sensory deprivation during this period leads to developmental delay and irreversible changes in the formation of behavior.
Active contacts in the form of play and aggressive clashes between the cubs begin very early, often even before the eyes open. On this stage development, they occupy almost the entire time of wakefulness of the cub. In the process of contacts with family members, he intensively learns the basic "laws of the hostel." Communicating with their peers, the cub masters the laws of hierarchy. This happens during joint games, and during the struggle for food, the best place to relax, etc. Dominance in cubs at this time is in the nature of a "swing": today - one, tomorrow - another, depending on their physical condition and relationships with their parents, who sometimes interfere quite intensively in games and conflict situations. An exceptionally important role in the development of the mental activity of an animal and the formation of its social behavior is played by play activity. Positive and negative emotions play an important role in regulating the behavior of a growing cub.
Predators begin to train the young in hunting behavior by bringing them half-dead prey. When the cubs, having killed the game, begin to eat it, parents often punish too greedy and aggressive offspring. The cubs of most species at this age still maintain stable contact with their parents and brothers and do not move farther away from the nest. Thus, the process of socialization at this stage of development mainly affects relationships within the family.
