The program of individual development of the organism is laid down in the zygote and its implementation begins already at the beginning of the formation of a new organism. The hereditary program of individual development at the first stage is determined, first of all, by the genotype and the environment created by the mother's organism. These two factors are regulated by endocrine mechanisms or by the pregnancy dominant. At the same time, the placenta, ensuring the optimal development of the fetus, should exclude the possibility of the penetration of high-molecular proteins from the maternal organism. In addition, the limited surface area of the fetal part of the placenta limits the excess supply of nutrients and oxygen from maternal blood to the fetus. The organism develops in conditions of a certain hypoxia.

For the fetus, at different stages of development, this phenomenon is a natural stimulus that determines its motor activity. It is irrefutable that the level of nutrition, metabolism, physical activity, conditions of maintenance and creation of the optimal morphofunctional status of the maternal organism predetermines the development of the fetus, according to gestation, and the birth of a new organism with a high morphofunctional status, which has a high viability. I. A. Arshavsky argues that an organism at all stages of ontogenesis, starting from its existence as a zygote, is mature and definitive to the extent that the features of its morphofunctional state adaptively correspond to those specific environmental conditions with which it interacts.

When determining the morphofunctional characteristics of neonatal animals, there is a direct need to identify periods of their growth and development, as representatives of maturonate and immaturonate animals.

Many researchers take the morphophysiological characteristics of animals and animals as the basis for determining the periodization of growth and development. the necessary conditions environment to show their viability. However, morphological studies show that a more informative criterion for the periodization of the development of an animal organism in ontogenesis is a phased qualitative and quantitative transformation of structures. Currently, the age periodization of animals, which is associated with zootechnical criteria, is more used.

Therefore, ontogeny is the individual development of an organism from the moment a zygote is formed to death. In turn, ontogenesis is divided into prenatal (before birth) and postnatal (after birth) periods. The prenatal period of ontogenesis is divided into stages: 1. Formation of a zygote. 2. Formation and differentiation of germ layers. 3. Prefetal. 4. Early fetal. 5. Late fetal.

At different stages of fetal development in the prenatal period of ontogeny, in violation of the placental barrier, changes occur that affect the morphofunctional status and viability of animals after birth, which we have already paid attention to.

We noted that newborn productive animals are diurnal animals that still retain the features of a late fetus. In animals with a high morphofunctional status, the latter disappear after one to two days (in immature animals, only after 20-24 days).

The postnatal period of ontogenesis is also divided into periods: 1. Newborn; 2. Dairy; 3. Puberty; 4. Physiological maturity; 5. Maximum productivity and 6. Old age.

First period - Newborn(colostrum, neonatal). Its duration is not the same in maturonate and immaturonate animals. However, the neonatal period has characteristic features for all animals - intensive changes in embryomorphological structures, to new ones, which are characterized by significant destruction against the background of the formation of new tissues.

This period is the most sensitive and at the same time the most adaptive to environmental conditions. In the first ten days of life of newborn animals, almost 90% of the mechanisms of unconditioned reflexes of adaptive reactions are triggered and the provision of status parameters internal environment organism. Some authors argue that the neonatal period, under appropriate growing and feeding conditions, optimally ensures the subsequent health and productivity of the animal. After all, it is known that when calves become ill in the neonatal period, their future productivity is reduced to 35%.

In healthy newborn productive animals with high viability (morphofunctional status reaches 90-100 points), the duration of the neonatal period is not the same. In calves and lambs, it continues until the beginning of the functioning of the proventriculus (10-14 days). In piglets, the newborn period lasts up to 20 days and it is somewhat longer in foals (25-30 days). During this period, in newborn productive animals, the stump of the umbilical cord dries up and disappears, conditioned reflexes to the source of food, place of existence, time of feeding are formed, and a genetic need for locomotion is manifested. The glands of the stomach begin to secrete hydrochloric acid, and the animals gradually switch to the food inherent in this species.

In newborn animals with signs of prenatal underdevelopment, this period can increase two to three times. The continuation of the neonatal period of animals in time depends on the intensity of the transformation of embryomorphological formations into structures characteristic of this period, which is determined by the characteristics of the intestinal type of digestion and motor activity. It should be noted that during this period, the transformation of uterine structures occurs most intensively, especially in the organs of universal hemoimmunopoiesis, as evidenced not only by the replacement of fetal hemoglobin with definitive hemoglobin, but also by qualitative changes in the morphological and biochemical composition of the blood. An increase in the number of factors and their slight fluctuation in the environment of keeping newborn animals contributes to the intensity of replacement of the uterine structures of their body at all levels of structural organization. Therefore, it is important to keep animals during this period in conditions that meet their biological needs. In this regard, the continuation of the neonatal period is significantly affected not only by the conditions of feeding, but also by the maintenance in the first days of life. The realization of the genetic need for active movement especially affects the growth and development of animals in the newborn period.

It should be noted that the health of productive animals and the realization of their genetic potential for growth, development, breeding qualities and productivity depend on the morphofunctional status of the body of newborn animals in the neonatal period.

milk period In calves it lasts 4 months, in foals - 6, while in piglets and puppies - 1.5-2 months. During the milk period, gradual structural and functional changes take place, and most of all in the organs of the digestive apparatus. There is a certain transition from the consumption of not only milk, but also feed of plant origin. As a result, the mucous membrane of the stomach and intestines intensively changes and their volume and length increase. At the end of the milk period, animals can fully use the definitive food inherent in this species. Implemented genetic possibility mammals to independent existence in the environment.

puberty characterized by rapid growth and development internal organs, reproductive apparatus and soma. The formation of the function of the gonads predetermines the release of hormones that contribute to the development of secondary sexual characteristics.

Period of physiological maturity It is characterized by a significant decrease in the relative mass of the skeletal system against the background of an increase in live weight and the manifestation of sexual dimorphism. The animal organism is capable of performing the function of reproduction.

period of maximum productivity. The intensive growth of bone organs ends, their complete synostosis begins. In organ tissues, structures are replaced and most parenchymal components are transformed in immunocompetent structures into stromal components enriched in fatty components.

In these age periods, structural and functional changes in the skeletal system occur, one of the main functions of which is the function of hemoimmunopoiesis. Due to the fact that the skeletal system ensures the well-being of the body, it becomes necessary to determine the periods of osteogenesis in animals after birth.

Despite the difference in the newborn period in time, in animals, there are several main stages of osteogenesis.

First stage- intensive transformation of prenatal structures in bone organs against the background of an increase in the amount of bone tissue and red bone marrow with minor macroscopic changes. There is an expansion of the epiphyseal ossification centers and new ones are formed, especially in the bone organs of the axial skeleton, which continues during the newborn period.

Second phase- intensive development and growth in the size of epiphyseal and apophyseal ossification centers. An increase in the amount of reticulo-fibrous bone tissue with intensive transformation into lamellar. The formation of a layer of compact bone tissue in the vertebrae and sternum. Replacement of red bone marrow with yellow (fatty), which is especially characteristic of tubular bones. Lasts during the milk period.

Third stage- intensive growth and slow development, which is manifested by a significant increase in the size of bone organs, an intensive decrease in the amount of cartilage tissue, the replacement of coarse fibrous bone tissue with a lamellar osteon structure, especially in the compact layer of tubular bone organs of the extremities. Complete replacement of red bone marrow with yellow in the tubular bone organs of the extremities. The appearance of separate accumulations of adipocytes in the bone organs of the axial skeleton and the sternum. Lasts through puberty.

Fourth stage- slow growth and intensive development. A decrease in the intensity of growth of the parameters of bone organs against the background of intensive replacement of coarse-fibered bone tissue with lamellar tissue and the formation of medium- and large-cell spongy bone tissue. Destruction of spongy bone tissue in the center of the epiphyses and filling with yellow bone marrow. Thinning of the articular and, especially, metaphyseal cartilage. Synostosis of the epiphyses: complete in the proximal epiphysis of the radius and distal - tibia and partially - in the distal epiphysis of the humerus and femur, insignificant - in the proximal epiphysis of the humerus and femur and absent - in the distal epiphysis of the radius. A significant thickening of the bone organs, due to compact bone tissue, continues until the end of the physiological maturity of the animals.

Fifth stage– slow and constant remodeling in accordance with static and dynamic loads. Remodeling (destruction and renewal) of bone tissue provides a constant composition of minerals in the blood, inducing the formation of single accumulations of red bone marrow, thinning of articular cartilage, destruction of metaphyseal cartilages and the formation of sclerotic lines from epiphyseal subchondral bone tissue in their place. Red bone marrow is contained in the sternum, vertebrae, and distal parts of the ribs. It continues during the productive period, at the end of which there is a decrease in the amount of bone tissue as a result of the predominance of destruction processes over formation processes, which induces the phenomena of physiological osteoporosis.

Determining the stages of morphogenesis of bone organs on the basis of their structural features and associated with the function of hemoimmunopoiesis provides an opportunity to create appropriate conditions for feeding and keeping animals, and use these data when diagnosing a violation of the structure and function of the skeletal system.

Agarkov A.V. FGBOU VPO "Stavropol State Agrarian University", Stavropol

Introduction. The immune system does important role in maintaining the structural and functional constancy of the newborn organism. After birth, in order to resist many etiological pathogenic substances, animals must have a high level of immunobiological protection. Individuals with a reduced immunobiological status do not realize fully programmed genotypic capabilities in the early stages of postnatal development. Therefore, targeted identification of lagging links in the neonatal periods of development will help to maximize the individual reserve of the animal organism and determine a set of preventive preventive measures. In this connection, the study of the characteristics of the immunobiological status in the neonatal period becomes relevant and significant for veterinary science and practice.

The aim of the work was to identify neonatal features of the immunobiological status in newborn piglets.

Material and research methodology. The studies were carried out in the subsidiary farm of the Stavropol Territory. For the study, 20 piglets were selected from the sows of the Large White breed of the first farrowing in the neonatal period.

In piglets on the 3rd, 5th, 10th day after birth, the following indicators were determined: hematological - the number of leukocytes, lymphocytes, erythrocytes; specific indicators characterizing the overall resistance - functional activity of neutrophils, phagocytic index, phagocytic number, phagocytic blood capacity, as well as bactericidal and lysozyme activity of blood serum; the content of the main classes of immunoglobulins - IgA, IgG, IgM.

The functional activity of neutrophils was assessed by phagocytic activity (PAN%), phagocytic number (PF), phagocytic index (PI), phagocytic blood capacity (FEC) - by DC. Novikov (2001). The bactericidal activity of blood serum - according to O.V. Smirnova and T.A. Kuzmina (1966), alizozyme activity of blood serum - according to V.T. Dorofeichuk (1998).

Digital data are processed by biometric methods according to N.A. Plokhinsky (1987), using applied computer programs Microsoft Excel and Biostat.

Results and discussion. From the data presented in Table 1 and Figure 1, it can be seen that the indicators of the immunobiological status are in trends of decreasing values over the period of neonatal development.

Table 1. Indicators of the formation of the immunobiological status of piglets in the neonatal period

Indicators	Research period, days
Indicators
Leukocytes, 109/l
T-lymphocytes, %
B-lymphocytes, %
Erythrocytes, 1012/l



FEK, thousand/mm3

Rice. 1. Formation of the immunobiological status of piglets in the neonatal period

In piglets, the content of leukocytes for the selected period of the study was subject to fluctuations. So, on the 3rd day it was - 6.73±0.12*109/l, on the 5th day - 5.21±0.17x109/l and on the 10th day - 5.88±0.14x109 /l, respectively. The quantitative composition of lymphocytes for the analyzed periods, namely T-lymphocytes, was on the third day - 32.69±1.13%, which was higher by 31.6% than on the fifth and by 13.3% than on the tenth day after birth . However, the level of B-lymphocytes was significantly increased on the tenth day and amounted to 17.07±0.44%, despite this, by the third day it was 10.61±0.41% and by the fifth day it was 7.33±0.15 %.

The number of erythrocytes in piglets varied within physiological values from 2.45±0.38x1012/l on the third day to 2.68±0.11x1012/l on the tenth day without sharp declines and rises.

The most vulnerable link in the specific indicators of the natural resistance of the body of piglets was the functional activity of neutrophils - in particular, their phagocytic ability, which tended to decrease and amounted to 32.41 ± 2.03% - on the third day, on the fifth - 21.15 ± 1, 21, in the tenth - 18.03±2.84%.

Changes in the bactericidal activity of blood serum over the period of the study took the following values - 27.52±2.41%, 22.97±2.08%, 29.18±1.52%, and lysozyme activity of blood serum - 24.48±1 .54%, 13.36±1.12%, 19.45±1.06%, which also confirms the decrease in the rate of natural resistance over the analyzed period.

Age levels of the main classes of immunoglobulins (IgA, IgG, IgM) in the neonatal period indicate the activation of immunogenesis in piglets to the greatest extent on the third and tenth day after birth. The level of immunoglobulins on the fifth day of the neonatal period in the study of the offspring acquired deficient values in relation to the 3rd and 10th day of the studies. So the concentration of IgA was on the 3rd day - 0.24±0.01 g/l, on the 5th day - 0.11±0.01 g/l and on the 10th day - 0.34±0.02 g/l. IgG - (3.42±0.05 g/l, 2.73±0.02 g/l, 3.89±0.05 g/l), and IgM - (0.47±0.03 g/l l, 0.21±0.06 g/l, 0.51±0.07 g/l).

Conclusions and conclusion. Based on the results of the study, it can be concluded that the immunobiological parameters of piglets in the neonatal period are of a wave-like nature of formation, and on the fifth day after birth they are characterized by instability, this is expressed in reduced values in relation to the third and tenth day of the study. This unfavorable (critical) period implies the highest intensity of metabolic processes, greatest opportunity disruption of adaptive mechanisms, making at this moment the resulting offspring more susceptible and less stable, which must be taken into account when growing piglets.

Bibliography:

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Dmitriev, A.F. Forecasting the viability of newborn lambs / co-authors: E.I. Postnikov, A.U. Ediev, A.N. Simonov, D.A. Isabaeva // Sheep, goats, wool business. - 2001. - N ° 4. - S. 26-29.
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Summary. Compared to other farm animals, piglets are among the most functionally immature. Their immune response is not perfect, since the activity and number of immunocompetent cells is low, the level of antibody synthesis is lower than in adults, and therefore the susceptibility to pathogenic factors is higher. The most developed newborn piglets normalize the formation of immunobiological potential faster.

Improving the safety of newborn piglets is a topical task for domestic and foreign veterinary medicine. To solve it, various methods of technological and medical nature are proposed. Most of these methods are aimed at improving the immunobiological status of piglets. Meanwhile, there is very little information in the literature about the physiological parameters of the cellular and humoral structures of the blood of piglets in the neonatal period, which makes it possible to adequately assess the state of resistance of the examined livestock and the magnitude of the impact of technogenic, medicinal and antigenic factors on it.

In this regard, we conducted a study of a number of immunobiological indicators of large white piglets. The aim of the work was to identify neonatal features of the immunobiological status in newborn piglets. The features of the formation of the immunobiological status in newborn piglets in the neonatal period were revealed. The data obtained can be used to increase the survival and safety of piglets in the early periods of ontogenesis. It has been scientifically proven that the level of immunobiological protection of the organism and the adaptive potential to the conditions of the environment are interdependent and interdependent. Therefore, the study of the mechanisms of the formation of the immunobiological status in the neonatal period has ultimate goal substantiation of the intensity of the body's defense.

Introduction

Progressive methods of growing young cattle require the organization and implementation of a scientifically based system of zootechnical, veterinary and organizational and economic measures.

Breeding should be organized in such a way as to ensure optimal growth and development of young animals with rational expenditures of labor and feed, and thereby lay the foundation for the subsequent productivity of adult animals. Proper rearing of young animals largely determines the optimal manifestation of the genetically determined productivity of animals.

Under the conditions of specialization and intensification of animal husbandry, knowledge of the patterns of growth and development is of particular importance. Characteristics early age period, how can full use. It should be taken into account, for example, that the energy of growth decreases with age, and the payment for feed, i.e. feed consumption per kilogram of growth increases.

Proper feeding of calves in the first days and weeks of life is one of the key factors that guarantee the full growth and development of animals. Only a healthy calf can become a highly productive cow in the future. This is confirmed by the results of scientific research and the practice of efficient livestock breeding. A dietary deficiency of at least one nutrient causes disturbances in the development of organs and tissues with a high growth rate, which reduces the viability and resistance of the calf to diseases.

During the milk period, young cattle are especially in need of full feeding and most fully balanced elements nutrition. At this age, young cattle are especially sensitive to the lack of micro-macro elements, vitamins and other biologically active substances.

Enrichment of diets with a complex of biologically active substances is a simple and at the same time effective opportunity to increase the productivity of farm animals in general, and young cattle in particular.

aim thesis- was the study of the effectiveness of the use of Biavit 30-optim when growing calves in the milk period.

In connection with the above, in our work we set the following tasks:

1. To reveal the influence of the Biavit 30-optimum additive on the growth and development of calves.

2. Determine the effectiveness of biavit-30 optima on feed costs per unit of production.

3. Determine economic efficiency the use of biavit in the cultivation of calves of the dairy period.

Literature review

Features of physiological processes in the early period of life of calves

Newborn animals in the species aspect are born with varying degrees of physiological maturity and not all of them can exist independently, but depend on the mother's body, which through milk makes a subtle connection with the born offspring. Such relationships between mother and offspring were formed during a long phylogenetic development and have survived to this day. Newborn calves, unlike adult animals, have their own physiological characteristics. In the postembryonic period of development, morphological, biochemical and physiological changes occur in the body of young animals. With age, the amount of water in the body decreases. So, the ratio of protein to water in the tissues of a newborn is 1:5, 1:6, in an adult - 1:4. Tissue proteins play an important role in water metabolism (which is very intense in the first days of life); in newborn young animals, they are in a state of significant swelling, which decreases with age. The body of a newborn animal is characterized by a number of physiological and biochemical features: it has a weak mechanism for regulating body temperature, water and mineral metabolism, many enzyme systems are poorly developed or have not yet been created. For the first time in the life of young animals, the blood has a slightly acidic or neutral reaction (pH 6.8-7.0). Although the buffer systems of blood and tissues are functioning, they are not yet stable enough, and blood pH can easily shift. The blood serum of newborn calves contains almost 2 times less proteins. At the same time, the blood contains an increased amount of sugar, lactic acid, amide nitrogen and acetone bodies. Studies on the study of humoral protective factors have shown that they are mainly formed after birth due to maternal colostrum. In the process of individual development, the formation of individual factors of natural resistance is consistently noted. A feature of the central system is the immaturity of the cerebral cortex in the early stages of postnatal development. Nervous regulation of the basic physiological processes is carried out mainly due to unconditioned reflex reactions. And only later does the formation of conditioned reflexes take place, which allow the newborn to adapt to environmental conditions. The regulatory influence of the central nervous system on the functions of heat transfer, digestion, hematopoiesis increases gradually.

The metabolism is characterized by intensity and high level synthetic processes. Gas exchange in young animals is more intense than in adults, oxygen consumption is greater, and the release of carbon dioxide is more intense than in adults, which is an important factor in the regulation of acid-base balance. Thermoregulation is a complex neurohumoral process of maintaining a uniform body temperature with the help of physical and chemical processes. In newborn animals, this process is imperfect due to the lag in the development of the central nervous system and requires the stability of the environmental temperature for the first hours of the day of their life. Normally developed calves are born with all milk incisors and eight teeth (or they erupt for the first time days after birth). It is believed that the presence of four or fewer incisors in newborn calves is a sign of malnutrition. The stomach and intestines of newborn calves have a small capacity and contain viscous meconium accumulated during the period of fetal development. Of all the departments of the multi-chambered stomach at the time of birth, only the abomasum is well developed in the calf, which is why it bears the main burden in the process of digestion. The volume of abomasum is related to age, breed and depends on the size of the calf. The physiological capacity of the abomasum in newborn calves depends on the anatomical and physiological characteristics and development of the offspring. The abomasum rapidly increases and a few days after birth, its capacity can reach 4-6.5 liters. Calves weighing 32-35 kg, in the first days of life, can consume up to 12 liters per day with 6-8 meals a day, and some up to 20 liters. The rennet and intestines of newborn calves that are not covered with mucus still lack barrier functions, and protein, immune substances and microbes that enter the digestive organs are not exposed to digestive juices and penetrate through the mucous membrane unchanged. The gastrointestinal tract of newborn animals is free from microflora. However, already in the first day of life, it is populated by lactic acid bacteria and enterococci, bifidumbacteria, Escherichia coli, staphylococci. Moreover, the intestines are most quickly populated by Escherichia coli. With the timely receipt of high-quality colostrum by newborns, the colonization of the small intestine with lacto- and bifidumbacteria increases, the concentration of Escherichia coli decreases sharply, and it and other microflora populate the posterior intestine. During the colostrum period, the intestinal microbial landscape stabilizes both quantitatively and qualitatively.

The composition of the normal intestinal microflora of healthy calves consists of an equal number of lactobacilli, bifidumbacteria and Escherichia, while the number of populations of staphylococci is 2 times less. Numerous studies have established that calf saliva is similar to cow saliva and has an alkaline reaction (pH 8.0-8.2). The salivary glands of the oral cavity, parotid, submandibular and sublingual function normally from the first minutes of life, but they secrete little saliva. Amylase is an enzyme that causes the hydrolytic breakdown of glycogen and starch into glucose, maltose. Dextrin is missing. The saliva of young calves contains the enzyme lipase, which only acts on milk fat triglycerides. The optimal pH for lipase is 4.5-6.0. The release of lipase is activated in the process of sucking colostrum during drinking, and a strong stimulating effect is observed when using teat drinkers, from which colostrum comes slowly. Its activity decreases with the age of the calf, and by the age of 3 months it completely stops. The first ruminant in calves may appear as early as a week of age, but the ruminant periods are generally very weak; full reduction of the scar they begin only at the age of 21-30 days. The length of the small intestine is on average 16 m, thick - 2-3 m. Intestinal peristalsis in the first 10 days of life is inactive. Unlike adult animals, in which about 80% of the consumed feed is digested already in the rumen with the help of the microflora living there, a newborn calf has only a set of its own enzymes to use the nutrients entering the body. Some of them contribute to the assimilation of only proteins of fresh colostrum, other enzymes are involved in the process of splitting carbohydrates. Thus, the activity of intestinal lactose after birth is 10 times higher than the activity of maltose, so milk sugar (lactose) is digested immediately after the birth of a calf, and cane or beet sugar (sucrose) is not absorbed by the body. Until the age of 28 days, starch and its decay products (dextrin and maltose) are not digested, because the enzymes amylase (diastase) and maltose are in low concentrations in the pregastric and intestinal juices. The activity of lactose in the intestine decreases with age of the calves. In the first day of life, the intestines of calves, as a rule, are freed from the original feces (meconium). Almost all of the water and solids contained in colostrum are digested and absorbed. During the 2-5th day of life, calves excrete about 230 g of feces per day, consisting of an average of 74% water and 26% solids.

Of the features of the gastrointestinal tract of newborn calves, it should also be noted increased (compared to adult animals) eosinophilia of the mucous membranes and the richness of the small intestine in lymphoid elements. The barrier function of the liver in newborn calves is insufficient. The neutralization of toxic substances is weak, and therefore cases of intestinal intoxication and inflammation in the gastrointestinal tract are frequent in calves. In the first 10 days of life, the prothrombin index in calves is significantly lower than in adult animals. The liver of newborn calves is much richer in glycogen than in adult animals; hemosiderin is almost constantly detected in it, which is considered a pathology in adult animals. Up to 5 days of age, calves have bilirubinemia, which is explained by the weak conjugation function of the liver in relation to blood bilirubin. The excretory function of the liver in calves is at a low level. The presence of microcytosis in calves is the result of a general functional weakness of the liver and its low hematopoietic function. Thus, in the first days of life, liver function in calves in relation to the formation of blood proteins, hematopoietin, binding and excretion of bilirubin is lower than at an older age. This indicates a general hypofunction of the liver and its functional immaturity. Connective tissue in young animals is larger than in adults. The absorption function of RES cells (reticuloendothelial system) is increased, and the enzymatic function is reduced. Increased tissue absorption of young animals contributes to their susceptibility to a variety of infectious and toxic diseases. The light permeability of local barriers causes the entry of toxins into the parenchymal organs and the degeneration of the latter. This creates an opportunity for the appearance of bacteremia and generalization of the pathological process. Strengthening of proliferative processes causes the appearance of local infiltrative foci and hyperplastic processes in the regional lymphatic tissue. Infections and intoxications of a young organism are accompanied by a large leukocytosis, a strong destruction of erythrocytes, a large number pigments, strong absorption, insufficient antigen cleavage process. The body of calves up to 45 days of age does not produce antibodies to the introduced antigen, and in 30% of calves they are not produced until 6 months of age. The immune system is formed in newborn calves gradually. Even at the age of 45-110 days, she is weakly reactive.

With the timely intake of full-fledged colostrum, age-related immune deficiency is compensated, rather intense local and general immunities develop, and the digestive tract is populated with beneficial microflora. With a belated intake of colostrum or the intake of physiologically inferior colostrum in young animals, the formation of local and general protection is disrupted and mass gastrointestinal diseases. Clinically full-fledged calves are those that at birth have a live weight standard for the breed (6-8% of the mother's weight), rise to their feet after birth within 0.5-2 hours, have a pronounced sucking reflex and good appetite. Such calves after feeding have a cheerful appearance and frolic, cheerful, the coat is even, shiny. The original feces (meconium) are well formed. They show a strong reaction to a pinch in the croup (jumping up, jumping to the side). Defective (physiologically immature) calves are lethargic, inactive, lie and sleep a lot, with difficulty, reluctantly rise, the sucking reflex and appetite are poorly expressed. Body temperature in 1-3-day-old healthy calves ranges from 38.5-39.3 0 C, pulse rate - 150-170; the number of respiratory movements - 50-70 in 1 min. During the first days of life, the excretion of feces occurs on average 3 times, urine - 4 times a day.

The level of viability of newborn calves can be determined by the coefficient of catabolism:

where, M1 is the weight of the calf at birth;

M 2 - weight of the calf at the second weighing.

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Ministry Agriculture Russian Federation

FGBOU Ulyanovsk State Agricultural Academy. P.A. Stolypin

Essay

On the topic: "Physiological features of the development of calves after birth"

Completed by: 3rd year student, 2B group

Morozova A.K.

Checked by: Lyubin N.A.

Ulyanovsk - 2015

In the postembryonic period of development, morphological, biochemical and physiological changes occur in the body of young animals.

With age, the amount of water in the body decreases. So, the ratio of protein to water in the tissues of a newborn is 1:5, 1:6, in an adult - 1:4. Tissue proteins play an important role in water metabolism (which is very intense in the first days of life); in newborn young animals, they are in a state of significant swelling, which decreases with age.

The body of a newborn animal is characterized by a number of physiological and biochemical features: it has a weak mechanism for regulating body temperature, water and mineral metabolism, many enzyme systems are poorly developed or have not yet been created. In the first days of life of young animals, the blood has a slightly acidic or neutral reaction (pH 6.8-7.0). Although the buffer systems of blood and tissues are functioning, they are not yet stable enough, and blood pH can easily shift. The blood serum of newborn calves contains almost 2 times less proteins. At the same time, the blood contains an increased amount of sugar, lactic acid, amino nitrogen and acetone bodies.

Studies on the study of humoral protective factors have shown that they are mainly formed after birth due to maternal colostrum. In the process of individual development, the formation of individual factors of natural resistance is consistently noted.

A feature of the central system is the immaturity of the cerebral cortex in the early stages of postnatal development. Nervous regulation of the basic physiological processes is carried out mainly due to unconditioned reflex reactions. And only later does the formation of conditioned reflexes take place, which allow the newborn to adapt to environmental conditions. The regulatory influence of the central nervous system on the functions of heat transfer, digestion, hematopoiesis increases gradually.

Metabolism is characterized by intensity and a high level of synthetic processes. Gas exchange in young animals is more intense than in adults, oxygen consumption is greater, and the release of carbon dioxide is more intense than in adults, which is an important factor in the regulation of acid-base balance.

Thermoregulation is a complex neurohumoral process of maintaining a uniform body temperature with the help of physical and chemical processes. In newborn animals, this process is imperfect due to the lag in the development of the central nervous system and requires the stability of the environmental temperature in the first hours and days of their life.

Normally developed calves are born with all milk incisors and eight teeth (or they erupt in the first days after birth). It is believed that the presence of four or fewer incisors in newborn calves is a sign of malnutrition.

The stomach and intestines of newborn calves have a small capacity and contain viscous meconium accumulated during the period of fetal development. Of all the departments of the multi-chambered stomach at the time of birth, only the abomasum is well developed in the calf, which is why it bears the main burden in the process of digestion. The volume of abomasum is related to age, breed and depends on the size of the calf.

The physiological capacity of the abomasum in newborn calves depends on the anatomical and physiological characteristics and development of the offspring. The abomasum rapidly increases and a few days after birth, its capacity can reach 4-6.5 liters. Calves weighing 32-35 kg in the first days of life can consume up to 12 liters per day with 6-8 single feedings, and some up to 20 liters.

The rennet and intestines of newborn calves that are not covered with mucus still lack barrier functions, and protein, immune substances and microbes that enter the digestive organs are not exposed to digestive juices and penetrate through the mucous membrane unchanged.

The gastrointestinal tract of newborn animals is free from microflora. However, already in the first day of life, it is populated by lactic acid bacteria and enterococci, bifidumbacteria, Escherichia coli, staphylococci. Moreover, the intestines are most quickly populated by Escherichia coli. With the timely receipt of high-quality colostrum by newborns, the colonization of the small intestine with lacto- and bifidumbacteria increases, the concentration of Escherichia coli decreases sharply, and it and other microflora populate the posterior intestine.

During the colostrum period, the intestinal microbial landscape stabilizes both quantitatively and qualitatively. The composition of the normal intestinal microflora of healthy calves consists of an equal number of lactobacilli, bifidumbacteria and Escherichia, while the number of populations of staphylococci is 2 times less.

Numerous studies have established that calf saliva is similar to cow saliva and has an alkaline reaction (pH 8.0-8.2). The salivary glands of the oral cavity, parotid, submandibular and sublingual function normally from the first minutes of life, but they secrete little saliva. Amylase is an enzyme that causes the hydrolytic breakdown of glycogen and starch into glucose, maltose. Dextrin is missing. The saliva of young calves contains the enzyme lipase, which only acts on milk fat triglycerides. The optimal pH for lipase is 4.5-6.0. The release of lipase is activated in the process of sucking colostrum during drinking, and a strong stimulating effect is observed when using teat drinkers, from which colostrum comes slowly. Its activity decreases with the age of the calf, and by the age of 3 months it completely stops.

The first ruminant in calves may appear as early as a week of age, but the ruminant periods are generally very weak; full reduction of the scar they begin only at the age of 21-30 days. The length of the small intestine is on average 16 m, thick - 2-3 m. Intestinal peristalsis in the first 10 days of life is inactive.

Unlike adult animals, in which about 80% of the consumed feed is digested already in the rumen with the help of the microflora living there, a newborn calf has only a set of its own enzymes to use the nutrients entering the body. Some of them contribute to the assimilation of only proteins of fresh colostrum, other enzymes are involved in the process of splitting carbohydrates. Thus, the activity of intestinal lactase after birth is 10 times higher than the activity of maltase, so milk sugar (lactose) is digested immediately after the birth of a calf, and cane or beet sugar (sucrose) is not absorbed by the body. Until the age of 28 days, starch and its decay products (dextrin and maltase) are not digested, because the enzymes amylase (diastase) and maltase are in low concentrations in the pregastric and intestinal juices. The activity of lactase in the intestine decreases with age of the calves. postembryonic young resistance physiological

In the first day of life, the intestines of calves, as a rule, are freed from the original feces (meconium). Almost all of the water and solids contained in colostrum are digested and absorbed. During the 2-5th day of life, calves excrete about 230 g of feces per day, consisting of an average of 74% water and 26% solids. In the next five days, the average daily amount of feces decreases to 110-120 g due to better digestion of the dense substances of colostrum.

The barrier function of the liver in newborn calves is insufficient. The neutralization of toxic substances is weak, and therefore cases of intestinal intoxication and inflammation in the gastrointestinal tract are frequent in calves. In the first 10 days of life, the prothrombin index in calves is significantly lower than in adult animals.

The liver of newborn calves is much richer in glycogen than in adult animals; hemosiderin is almost constantly detected in it, which is considered a pathology in adult animals.

Up to 5 days of age, calves have bilirubinemia, which is explained by the weak conjugation function of the liver in relation to blood bilirubin. The excretory function of the liver in calves is at a low level. The presence of microcytosis in calves is the result of a general functional weakness of the liver and, in particular, its low hematopoietic function.

Thus, in the first days of life, liver function in calves in relation to the formation of blood proteins, hematopoietin, binding and excretion of bilirubin is lower than at an older age. This indicates a general hypofunction of the liver and its functional immaturity.

Connective tissue in young animals is larger than in adults. The absorption function of RES cells (reticuloendothelial system) is increased, and the enzymatic function is reduced. Increased absorption of tissues of young animals contributes to their susceptibility to a variety of infectious and toxic diseases. The light permeability of local barriers causes the entry of toxins into the parenchymal organs and the degeneration of the latter. This creates an opportunity for the appearance of bacteremia and generalization of the pathological process. Strengthening of proliferative processes causes the appearance of local infiltrative foci and hyperplastic processes in the regional lymphatic tissue. Infections and intoxications of a young organism are accompanied by a large leukocytosis, a strong destruction of erythrocytes, the release of a large amount of pigments, strong absorption, and insufficient antigen cleavage.

The body of calves up to 45 days of age does not produce antibodies to the introduced antigen, and in 30% of calves they are not produced until 6 months of age. The immune system is formed in newborn calves gradually. Even at the age of 45-110 days, she is slightly reactive.

Clinically full-fledged calves are those that at birth have a live weight standard for the breed (6-8% of the mother's weight), rise to their feet after birth within 0.5-2 hours, have a pronounced sucking reflex and good appetite. Such calves after feeding have a cheerful appearance and frolic, cheerful, the coat is even, shiny. The original feces (meconium) are well formed. They show a strong reaction to a pinch in the croup (jumping up, jumping to the side). Defective (physiologically immature) calves are lethargic, inactive, lie and sleep a lot, with difficulty, reluctantly rise, the sucking reflex and appetite are poorly expressed.

Body temperature in 1-3-day-old healthy calves ranges from 38.5-39.30C, pulse rate - 150-170; the number of respiratory movements - 50-70 in 1 min. During the first days of life, the excretion of feces occurs on average 3 times, urine - 4 times a day.

The level of viability of newborn calves can be determined by the coefficient of catabolism:

Where M1- weight of the calf at birth;

M2- weight of the calf at the second weighing

At the same time, newborn calves may be tested for the McClure Aldrich hydrophilic test. The test is set up as follows: hair is removed from the unpigmented area of the skin in the animal under study in the standard way. In the center of the freed area, the skin is collected in a fold and measured with a caliper. Then, 0.5 ml of saline is injected into the crest of the fold. After injection, the resulting seal is measured. In the future, the measurement is repeated every 10-15 minutes. until complete absorption of saline.

It has been established that in calves with normal viability, the catabolism coefficient is 0.99-1.05, the thickness of the skin fold is 6-7 mm, and the resorption of saline occurs in 45-60 minutes. Deviation to the side indicates an increase or decrease in the reactivity of the animal. In hypotrophic calves with reduced viability, the catabolism coefficient is less than 0.99, and the resorption of the solution occurs within 20-30 minutes.

Newborn calves with a low coefficient of catabolism under adverse environmental influences are predisposed to diseases of the gastrointestinal tract.

Thus, the determination of the neonatal viability index is not very difficult and makes it possible to focus on physiologically weak calves before they develop clinical signs of the disease.

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The problem of early and correct diagnosis of the disease in young animals, as well as the implementation of effective treatment and prevention measures, is largely determined by the characteristics of the growing organism, which vary widely depending on the age of the animal.
Newborn animals are considered physiologically mature if their morphophysiological constants correspond to their age.
With morphophysiological maturity, the body weight at birth of an animal varies depending on the breed within the following limits: for a calf, 20-45 kg, or 7-9% of the mother's body weight, for a piglet, 1.0-1.5 kg, or 0.5-1. 0% body weight of a sow, lamb - 2.0-4.3 kg, or 6-8% of the weight of a ewe, foal - 26-50 kg, or 8-12% of the mother's body weight. The body length of a newborn calf is 70-95 cm, a piglet - 20-25 cm, a lamb - 3050 cm, a foal - 75-145 cm. At birth, a piglet has 4 fangs and
4 lateral incisors, calf 4-6 incisors and 12 molars, lamb
6 cutters.
In the first hours after birth, the rectal temperature in calves is 37.6-38.4°C. At the age of one day, it increases to 38.7-38.9°C, and then rises to 39.2-39.5°C. During the neonatal period, young animals have a stump of the umbilical cord, which is treated with an iodine solution. It disappears in piglets on the 5-7th day of life, in calves after 8-10 days, in foals by the 10-12th day.
In newborns, a number of unconditioned reflexes are well expressed, in particular, food and thermoregulation, and they largely characterize their physiological characteristics. Already in the first hours, the sucking reflex is pronounced, which is manifested in food searching movements. Pigs, lambs, foals suckle every 0.5-2.0 hours. The calf suckles an average of 5 times on the first day, and 6-8 times on the next three days. The duration of one feeding is from 2 to 25 minutes. A calf sucks out 6-8 kg of colostrum per day. The frequency of sucking movements can be up to 120 per minute, a portion of a sip is up to 5 ml.
The digestive system at the birth of calves is characterized by the following approximate values: the volume of the rumen is 730 ml, the abomasum is 1250 ml, the length of the small intestine is 15.9 m, the large intestine is 2 m. In newborn piglets, the capacity of the stomach is on average 25 ml, the length of the small intestine - 3.8 m, and the capacity is 100 ml, the length of the large intestine is 0.8 m.
In the first 10-15 days of life in calves, the capacity of the rumen and especially the abomasum increases significantly. So, in 15-day-old calves, the volume of the scar reaches
1.3 l, and abomasum - 4 l, the length of the small intestine increases to 20.6 m, the large intestine - up to 2.7 m. In 10-day-old piglets, the volume of the stomach is already 73 ml, the length of the small intestine is 5.5 m , and the volume is up to 200 ml, the length of the large intestine is up to 1.2 m, and the capacity is 90 ml.
The act of sucking is accompanied by the secretion of saliva. In the first days after birth, the submandibular and sublingual glands secrete more actively. With age, the parotid glands are also included in the secretion. Mixing milk with saliva is an important factor in the prevention of the disease, as it contributes to the formation of small loose clots of casein in the stomach, available for further digestion. In newborn ruminants, this is also facilitated by the manifestation of the esophageal trough reflex, when, bypassing non-functioning, in contrast to adults, proventriculus, the received colostrum enters the abomasum. The proventriculus begins to function as the calves and lambs are accustomed to feeding with coarse and succulent feed, then the act of chewing appears, which occurs in calves at the age of 12-14 days and later. During the period of milk feeding in young animals, the intestinal type of digestion is more pronounced. The abomasum of dairy calves, lambs, unlike adult ruminants, contains a relatively large amount of the enzyme rennin (chymosin), which contributes to the coagulation of milk caseinogen and the formation of small loose clots for further splitting. Free hydrochloric acid in the first 2 hours of life of calves and up to 14-20 days of age in piglets is not found in the stomach, which facilitates the absorption of immunoglobulins from maternal colostrum in the first hours after birth, which are then evacuated to the intestine, where they are absorbed by the epithelial cells of the mucous membrane of the thin intestines by pinocytosis and enter the lymph, and then into the blood. This feature in newborns is most pronounced in the first 12-24 hours, and by 36-48 hours after birth it stops.
Consequently, the humoral resistance factors in the first days after birth in young animals depend entirely on the intake of immunoglobulins from outside with the mother's colostrum, and thus colostral immunity is created, and the production of own antibodies begins after 10 days of age in calves and after 12-15 days in piglets. . Therefore, it is extremely important for newborns to drink colostrum in the first hours after birth. In the first days of life in young animals, the cellular defense reaction is more pronounced than the humoral one.
The transition of newborns to environmental conditions with a lower temperature compared to the mother's womb causes significant changes bioenergy. The basal metabolic rate in calves is 3.6 kcal/hour/kg, in piglets 4.0-6.0 kcal/hour/kg, in lambs 1.92 kcal/hour/kg. From the moment of birth, the energy metabolism of young animals increases, which is associated with the regulation of thermoregulation mechanisms. In newborn young animals, basically the same amount of energy is spent per 1 kg of weight gain - about 4800 kcal of feed, with values of 1 kg of growth - 30 g of nitrogen and 1720 kcal.
The formation of energy processes is closely related to the features of the functions of other body systems and, in particular, the respiratory and cardiovascular systems. At birth, the first extrauterine respiratory movements occur, which is facilitated by the resulting significant negative pressure in the pleural cavity, which favors the expansion of the lungs. At the same time, it reveals great amount capillaries of the lungs, and blood from the right ventricle enters the pulmonary circulation. And then the blood is brought through the pulmonary veins into the left atrium, where high pressure is formed and the Eustachian valve closes the foramen ovale between the atria. In connection with the restructuring of blood circulation, the walls of the umbilical vessels collapse, the orange duct and umbilical arteries become obliterated.
The ability to maintain a constant body temperature is accompanied by increased oxygen consumption, the formation of greater heat production. This is facilitated by the activation of the central mechanisms of thermoregulation, an increase in the tone of the skeletal muscles and the activity of the respiratory muscles due to irritation of the receptors of the skin and lungs. Muscle tone is further enhanced if the cow licks the newborn. Licking or rubbing the body of a newborn causes it to be released from the waters covering the eyes. makes it possible to dry faster and thereby save the cost of your * shta. After birth, from the first minutes of life, the formation of heat in calves is more intense, less pronounced in newborn piglets and lambs. The establishment of perfection in thermoregulation in lambs occurs from the 2nd-3rd to the 16th day, and in piglets - by the 20th day of age.
The heart rate and respiratory rate in calves during the neonatal period is 134 and 47, in lambs 210 and 70-90, in piglets 248 and 86. 162 and 45, in piglets - up to 124 and 41.
In newborn young animals, the bronchi are narrower, there are few collagen elastic fibers in the lungs, and the diameter of the alveoli is smaller than in adult animals. This is associated with the presence of shallow breathing and with a lack of active movements, the preservation of atelectasis in certain areas of the lungs. During the neonatal period, the mechanisms of sympathetic regulation of the heart are predominantly carried out and this is manifested by its more frequent contractions.
Newborn young animals already have reflexes of a general and local nature from almost all receptors, and some of the reflexes are formed after birth. In the first days of life, a number of them appear, namely: sucking (food), motor, protective (blinking). With growth and development, sensitivity to pain reactions increases. On the 3rd-4th day of life, a conditioned reflex to certain time feeding, which is expressed in excitement and anxiety, an increase in the content of leukocytes in the blood before the start of the feeding period, etc. During the neonatal period, the adrenal glands and pancreas are actively functioning, but the endocrine function of the gonads is low and only increases with age. In general, anabolic hormones predominate at a young age. The motor reflex is manifested in calves in motor activity, which ranges from 200-500 movements in the first hours of life and 400-500 movements in the first day. The standing posture is realized in physiologically mature calves from 10-20 minutes to 70-80 minutes after birth.
Depending on the degree of deviations of environmental conditions from the required parameters, a stress reaction occurs, and as a result, either the adaptation of the organism or the occurrence of various pathologies takes place.
Classification of diseases of young animals. Growing healthy young animals, their safety from disease and death is one of the main tasks of animal husbandry. Its difficulty lies in the fact that the body of a newborn in the first days is poorly adapted to adverse environmental conditions due to morphological and functional features in the early postnatal period. Therefore, a number of diseases, their course, measures to combat them have their own characteristics.
The incidence and death of young farm animals from internal non-communicable diseases cause significant economic damage. The share of young animals accounts for approximately 75-90% of the case compared with adult animals, which indicates the great importance of timely diagnosis, treatment and prevention of diseases. Morbidity and mortality are most often observed during the neonatal period. In subsequent periods of growth and development of young animals, there are also features in the course of non-contagious pathology compared to that in adult animals.
The classification of diseases of young animals by origin provides for their division into the following four conditional groups: diseases caused by intrauterine fetal development disorders (antenatal); pathology in the offspring that arose during the mother's birth (perinatal); diseases during the neonatal period (neonatal) and diseases of the subsequent growth and development of young animals (postnatal).
According to the localization of the main pathological focus in individual organs or systems of the body, diseases of young animals are divided into diseases digestive system, respiratory, as well as a special group associated with metabolic disorders - deficiency diseases. The most specific of them are described in this section, and a number of others are described in the previous chapters of the textbook.
The objective of this section is to reveal the characteristics of diseases, taking into account the antenatal, perinatal and postnatal periods of development. The manifestation of diseases in the early postnatal period is closely linked with the morphological and functional characteristics of the offspring, which must be known and used in the targeted prevention of pathology, taking into account the antenatal conditions of the development of the organism.