Vol 18, No 1 (2023)

The study of variability of morphological features in red-colored varieties of amaranth and their correlations at different stages in the conditions of the Moscow region makes it possible to identify features that affect productivity, amount of amaranthine and other biologically active substances. After analyzing vegetative characteristics, the varietal features of amaranth plants were proved to have a smaller impact on ‘root length’, ‘plant height’ and ‘number of leaves’ characteristics than the cultivation conditions, especially at the initial stages (ISB (Influence share of the weather conditions) from 22 to 58 %). It follows from the phenotypic variability analysis that the genotypic component values varied significantly only at the last stages (Cvg > 35 %). The maximum values of phenotypic variability were marked in all varieties at the stage of active growth considering the ‘root length’ (Cve = 32…47 %) and the ‘number of leaves’ (Cve = 48…85 %). The generative characteristics seemed to be significantly influenced by the varietal factor (ISA (Influence share of varietal characteristics) = 40…88 %) starting from the third stage. The genotypic component of all varieties was high considering the inflorescence weight (Cvg = 75…86 %). In signs of general productivity, it was studied that the leaves (93…112 g/plant) contributed the most for amaranth forms, which mass in all varieties largely depended on weather conditions (ISB > 55 %). The interrelation of the leaves productivity was noted high with all the vegetative characteristics on phase III-V (r = 0.71…0.92) and with ‘inflorescence mass’ on phase V-VI.

As development of mushroom industry in Russia is growing, and the amount of spent mushroom composts is increasing, they are actively used as organomineral fertilizers for agricultural crops. Therefore, from the rather large problem of storing waste composts, these fertilizers began to be in great demand in the agricultural industry. Organic fertilizers are characterized by a high percentage of nutrients. They are able to improve physical properties of soil by increasing aggregative stability and reducing soil density. Organic fertilizers improve biological and biochemical properties of soil, and positively affect the development of soil microbial community. In the experiments, the content of nutrients in fresh compost and compost after one year of storage averaged: ash content - 8.0 and 74.1 %; organic matter - 66.3 and 25.9 %; NPK (%) - 0.50, 0.63, 0.44 and 0.45, 0.51, 0.39, respectively, under a favorable soil acidity (pH 8.0-7.3). In studies carried out on dark grey forest soils of the Ryazan region, the maximum productivity of agricultural crops was noted in variants with application of half-ripened compost: the yield of spring wheat was 2.82 t/ha (+ 0.23 t/ha compared to the control); spring barley - 3.21 t/ha (+0.17); spring rapeseed - 1.77 t/ha (+0.24); potato cv. ‘Vympel’ - 27.91 (+ 4.41); potato cv. ‘Kolobok’ - 11.21 t/ha (+1.63); pea - 2.10 t/ha (+0.21). The high efficiency of spent mushroom composts as fertilizers for increasing yields of spring barley and wheat, spring rapeseed, potatoes and peas was confirmed.

The aim of the research was to study water-physical properties of chestnut soils under different tillage practices when cultivating corn (Povolzhsky 89 MV hybrid) under irrigated conditions in the Lower Volga region. Therefore, the following characteristics of the soil were studied - soil density, soil moisture, field capacity, maximal hygroscopic moisture, wilting point and porosity. The results revealed that after chisel loosening, a qualitative improvement of soil water-physical properties was observed in comparison with the control variant - moldboard plowing. To describe the dynamics of changes in soil density by layers and tillage variants, a regression of the 2nd order was proposed, and coefficients of the equation were calculated. In order to maintain the specified irrigation regime during the observation periods, 7 to 9 vegetative irrigations with application rate from 2250 to 2750 m3·ha-1 were carried out in the variants with moldboard plowing, 7 to 8 irrigations with application rate from 2200 to 2600 m3·ha-1 in the variants with chisel loosening, and 6 to 7 irrigations with application rates from 2100 to 2500 m3·ha-1 in the variants with chisel moldboard plowing. The yield of corn in the variant with chisel moldboard plowing averaged 8.75 t·ha-1 during the research period, which is 18 % higher than in the control variant. Moreover, the cost of irrigation water for producing one ton of grain decreased by almost 20 %, and the coefficient of water consumption decreased by 17 %.

At present, there is scientific and practical interest in the study of morphological and physiological features, criteria and tolerance of organs involved in protein metabolism in representatives of the order Chiroptera. Macro- and micrometric indicators of kidneys in soprano pipistrelle (Pipistrellus pygmaeus), as a result of adaptive transformations of the body to habitat conditions in the Bryansk region were studied. The study was conducted in the period from 2011 to 2022, 40 captures were carried out with a total of 481 individuals, of which 100 were selected for further study. On histological preparations of kidneys of soprano pipistrelle (Pipistrellus pygmaeus), morphometry of nephrons, podocyte parameters, nuclear-cytoplasmic ratio, areas of nucleolar organizers and their total area were studied. It was established that biological adaptation of the bats (Chiroptera), on the example of soprano pipistrelle (Pipistrellus pygmaeus), is manifested in development of biological properties of the species. The functional and protein-synthetic activity of cells, kidneys (cell volume, nucleus, cytoplasm and nuclear-cytoplasmic ratio), the number and increase in the total area of the argentophilic region of nucleolar organizers were determined by organ topography, gender and influence of anthropogenic negative environmental effects. The data obtained showed gender differences in female bats (Chiroptera) of Pipistrellus pygmaeus species living in an urban environment, having a large number in the colony, against the background of a combined anthropogenic load, under the influence of hydrocarbons, sulfur and nitrogen dioxides and suspended solids. It was found that phenotypic adaptation as an adaptation to flight triggers the main processes of biochemical cycles, the processes of endogenous intoxication and detoxification function in kidneys. In turn, it increases metabolism, which contributes to increase in the number of renal glomeruli and decrease in the cavity of renal glomerular capsule. New data characterizing nuclear-cytoplasmic ratio, number and total area of regions of nucleolar organizers in podocytes of glomeruli in kidneys of soprano pipistrelle (Pipistrellus pygmaeus), which may be a manifestation of genetic adaptation to environmental conditions, were obtained.

In Russia, the number of beef cattle until recently was concentrated mainly in Kalmykia and adjacent regions. However, the lack of purposeful breeding has led to the fact that the purebred livestock of Kalmyk meat breed has significantly decreased and lost its unique qualities. Introduction of embryo transfer biotechnology can solve the problem of restoring breed qualities under the condition of accelerated reproduction of genotyped livestock. The aim of the research was to study Kalmyk breed response to polyovulation considering further increase in transferrable embryo productivity - the main indicator specific to each breed. As the formation of the breed took place in pasture conditions with a pronounced seasonal sexual cycle, there were doubts about the possibility of using embryo transfer technology in any season. The experiments were carried out on Kalmyk cows at Kalmytskoye farm in 2010 and at the Regional Research and Production Center for Reproduction of Farm Animals, Kalmyk State University, in 2022. The results of the study showed that it was better to synchronize sexual hunting using prostaglandins after 3-4 months after calving (May-October). According to the results of immunogenetic testing, 10 breeding cows and 2 breeding bulls were selected as donors. In September-October, in order to test the embryo transfer method in nomadic animal husbandry, the first work was carried out to stimulate poliovulation and obtain embryos from 3 donor cows. A total of 23 embryos and eggs were obtained, 10 of which were suitable for transplantation. Transferrable embryos were frozen on a ZEM-4 software freezer after equilibration in 1.5 M ethylene glycol cryoprotector solution.

Changes in live weight, morphology of carcasses, their morphometric parameters, chemical composition of muscles during cage rising (group 1) and ground-grazing raising (group 2) were studied in hens (‘Smena 9’ cross) at the age of 1, 35, 42, 49 and 56 days. Generally accepted research methods were used. The hens were raised under the same conditions. The experiments revealed that chickens had a high growth rate at an early age. At 56-day age, live weight of hen from group 1 was 3438 g, which was 2.69 % less than in group 2, and carcass weight was 2.89 % less (P < 0.05). In carcasses of broilers from group 2, weight of muscle tissue was 3.14 % more (P > 0.05), however, fat and bones were less by 0.22 and 0.09 %, respectively. Compared to 1-day-old chickens, 56-day-old broilers had increased relative weight: muscle tissue in group 1 and group 2 - by 13.04 and 13.27 %, respectively; fat - by 4.02 and 3.80 %, respectively; while relative bone weight decreased by 16.25 and 16.34 % in group 1 and group 2, respectively. Ground-grazing raising of chickens is not inferior in meat productivity to cage rising. At the same time, veterinary and sanitary indicators differ in the quality of meat.

Molecular genetic technologies are taking an increasing place in breeding work to improve existing breeds and populations of chickens, as well as in programs to preserve a valuable gene pool. Small local breeds are a source of valuable genes that can be used in breeding. The aim of this work was to obtain new knowledge about the structure of genomic DNA of six chicken populations using multilocus analysis with a labeled molecular probe (GTG)5. Multilocus analysis using labeled DNA probes provides working simultaneously with a large number of genetic loci and calculating population genetic parameters both within populations and between them. The data on use of the multilocus probe (GTG)5 in molecular hybridization reaction in six breeds and populations of chickens were analyzed. The results revealed a large genetic distance between Black-and-White Australorp and the Bald-necked chickens (D = 0.155). Bald-necked chickens are bred in isolation from other breeds to maintain the unique trait of ‘naked necks’. According to the criterion of average heterozygosity, the population of Bald-necked chickens surpassed the Yurlov Crowers and Black-and-White Australorps. Obviously, this is due to the intensive breeding work carried out in the last two populations, which reduces genetic diversity. Marker DNA fragments specific for individual breeds were identified. The effectiveness of multilocus analysis as a tool for identifying the features of genome organization in chicken breeds and populations was confirmed.

To date, there is no registered injectable dosage form of levocarnitine for veterinary use on the territory of the Russian Federation. Based on the above, the purpose of our work was to conduct preclinical studies of L-carnitine of subchronic toxicity for veterinary use in laboratory animals. Experiments to test the toxicity were performed on outbred rats in October 2021 at the vivarium of St. Petersburg State University of Veterinary Medicine. The study involved females weighing 190…210 grams, purchased from RAPPOLOVO Laboratory Animal Nursery. To study subchronic toxicity via subcutaneous injection, L-carnitine was administered in 2 dose levels. The doses were determined based on the results of the acute toxicity experiment: 1/5 and 1/10 of the maximum tolerated dose. The first experimental group (n=10) received the drug subcutaneously at a dose of 0.08 mg/kg (1/5 of 2000 mg/kg). The second experimental group (n = 10) received the drug subcutaneously at a dose of 0.04 mg/kg (1/10 of 2000 mg/kg). The control group (n = 10) received sodium chloride 0.09 % subcutaneously at a dose of 1/5 of 2000 mg/kg. The drug was administered subcutaneously daily for 42 days. Killing and blood sampling from the second half of the animals was carried out after assessing the recovery period (10 days after drug cancellation). As a result of studies of subchronic toxicity of subcutaneously administered L-carnitine for veterinary use in laboratory animals, it was found that the dosage of 1/5 of the maximum tolerated, and the dosage of 1/10 of the maximum tolerated, do not cause external signs of toxicosis and death of rats. No significant changes in the hematological parameters of blood of animals from the experimental and control groups were found.

Acute bacterial cholangiohepatitis of cats is a common disease associated with the inflammation of bile ducts and liver parenchyma, characterized by development of a pronounced hepatodepressive syndrome (hypoalbuminemia), cytolysis (increase in serum activity of alanine and asparagine transaminase), cholestasis (increase in serum concentration of bilirubin, cholesterol, activity of alkaline phosphatase and gamma-glutamyltranspeptidase), intoxication, dehydration, mesenchymal-inflammatory and pain syndromes. The aim of the research was to study the effectiveness of treatment for acute bacterial cholangiohepatitis in cats with average severity of the pathology course. According to inclusion and exclusion criteria, the study included a cohort of cats (n = 12) with acute bacterial cholangiohepatitis. Clinical, hematological, ultrasonographic, statistical methods of investigation were used in this work. For sick cats with medium severity form of cholangiohepatitis, when administered as a complex therapy the combination of marbofloxacin, metronidazole, ursodeoxycholic acid, cyancobolamine, tocopherol acetate, infusion therapy also had a good therapeutic effect, which was accompanied by improved clinical and laboratory performance. In the blood of cats with cholangiohepatitis, in the background of intensive therapy, there was a significant decrease in white blood cell count, erythrocyte sedimentation rate, and in serum, there was an increase in albumin concentration, reduction of creatinine, aminotransferase activity, alkaline phosphatase, gamma-glutamyltranspeptidase, lipase.