PATHOLOGICAL CHANGES IN THE BODY OF PIGLETS WITH RESPIRATORY SYNDROME

Abstract

In pig farms, diseases of viral and bacterial etiology, with a predominance of damage to the respiratory system, occupy a significant proportion. Such animals have the conditions for the involvement of respiratory pathogens such as mycoplasma, actinobacillus bacteria, pasteurella and other microorganisms in the pathological process. Respiratory pathological processes in the respiratory system have a significant spread in young animals. The main etiological factors are also the violation of the parameters of the microclimate, the maintenance of piglets and the influence of specific and non-specific microflora on the animal body. Based on the results of research, it was determined that the causes of the development of respiratory pathologies can be invasive pathogens, especially nematodes, which have a specific location in the respiratory tract. The peculiarity of the development cycle of metastrongylus parasites, roundworms and their penetration into the respiratory system leads to the manifestation of respiratory syndrome in the early stages of growth and development of the organism. It follows the fact that due to the incomplete development of the immune system, in immature piglets, the respiratory tract is susceptible to numerous pathogens that cause a number of potential respiratory diseases. Piglets at weaning are particularly sensitive to changes in housing and feeding conditions, which is manifested by an energy-deficient state and a decrease in resistance. The research was carried out in the farms of VSK «Zorya», PSP «Kamishanske» of two bordering regions of Sumy and Chernihiv in the period 2021-2022. To establish the etiology of respiratory diseases and the energy-deficient state of piglets after weaning, samples of blood and pre-starter compound feed were taken. The selected material was sent for research to the regional laboratory and to DNDiLDVSE. Gas composition and concentration of bicarbonates were determined in the immunological department. The concentration of glucose, triglycerides, lactate, total cholesterol, which play a significant role in energy deficit in the body of young animals, was evaluated. Feed samples were examined in the toxicology department. The effectiveness of the transition from the dairy period to vegetable feeds depends on the digestibility of the components of compound feed. Our work was aimed at researching selected samples of compound feed. Examination of laboratory studies confirmed the presence of mycotoxins in 1 kg of compound feed with a probably permissible concentration. Despite this, it has been proven that their continued feeding contributes to the accumulation of mycotoxins in the body of piglets at weaning, and provokes the development of pathological processes in internal organs. Early changes in biochemical indicators in the piglets’ body were determined. For this purpose, three groups of clinically healthy piglets were formed at weaning of 10 heads each. By age: at 28, 45 and 60 days after birth. Blood gas composition and bicarbonate concentration were measured using a gas analyzer. When evaluating the effectiveness of antibacterial drugs, which were used for the preventive stage of respiratory syndrome in piglets, the active substance of the drug was taken into account. A semi-synthetic antibiotic of the group of macroliths was used tulorithromycin in a dose of 100 mg/ml. Our research was aimed at establishing the effectiveness of antibacterial agents in preventive measures. As a result of the conducted research, when analyzing the morbidity and survival of piglets, it was established that during the last two years the number of piglets dropped by 37.7% due to various reasons. This figure was 14.7%, especially in the area of rearing piglets. Based on the results of research, changes in the acid-alkaline balance in the body of animals were analyzed. In the blood of piglets, at the age of two months of their vital activity, blood oxygen saturation decreases with a simultaneous decrease in partial pressure. A simultaneous increase in the concentration of carbon dioxide and the level of bicarbonates is monitored. Studies have proven that the concentration of glucose in the blood of piglets decreases by 2.2 times, TG by 2.26, OX by 1.82. A simultaneous increase in lactate concentration by 2.4 times, CT by 1.97 was observed. The energy deficit that occurs in piglets at weaning is due to many factors, one of which is the acidity state of the body, the process that develops with respiratory tract pathology. Respiratory disorders, with the accumulation of non-oxidized decay products in the blood leads to the blocking of the enzymatic system, which provides the body with energy. In the clinical manifestation of such disorders, aerobic oxidation of carbohydrates occurs and a simultaneous increase in the processes of anaerobic oxidation. This process is accompanied by the accumulation of lactate and ketenes bodies in the body. The residual level of lactate and KT, which include acetoacetic and B-oxybutyric acid, leads to the development of metabolic acidosis. Persistent metabolic acidosis increases the acidotic state of the body. It is not possible to increase the energy deficit by feeding the animals compound feed, because precisely by inhibiting the processes in the piglets’ body, they lead to a decrease in appetite, rejection of feed, a decrease in live weight and even to their death. It is determined that after weaning, in the following two weeks, poor digestibility of feed, insufficient assimilation of nutrients is observed. These factors contribute to a decrease in immunity, resistance of the body and a decrease in average daily gains. Such parameters indicate, first of all, morpho-physiological changes in the gastrointestinal tract of young animals. Therefore, especially in the postweaning period, compound feed enriched with proteins and a complex of vitamins is used to prevent the death of piglets. Modern piglet farming is aimed at the application of scientifically based, universal feeding schemes. Feeding of piglets in farms, starting from the four-day age of vital activity, is carried out with special pre-starter compound feeds, the daily dose is provided for 20g. Already in the post-weaning period, the animals begin to get used to the new feed, it is important that the piglets have free access to it. An insufficient indicator in animal feeding is a sharp change in the components of compound feed and their component recipes. Most often, this leads to a violation of digestion, metabolism and, accordingly, the general condition of piglets. Effective preventive measures are the basis for preventing the occurrence of respiratory diseases in piglets at weaning, which lead to the development of a persistent acidotic and energy-deficient state. To prevent the disease of young animals, a large number of antibacterial drugs are currently produced and used. It was determined that the system of developed preventive measures with the use of the antibacterial drug «Draksin», the active substance of which is tulorithromycin, which suppresses the biosynthesis of proteins, thanks to the connection with the bacterial cell. The effectiveness of the drug was determined by the survival of piglets by 96.7%. The circulation of opportunistic and pathogenic microorganisms in the weakened body of young animals with low resistance increases their virulence and characterizes the premorbid stage of the development of respiratory syndrome in piglets. The prospect of further research in this direction is the development of comprehensive prevention of respiratory pathology and the search for effective means of protection for piglets at weaning.