Bulletin Samara State Agricultural Academy

The purpose of the research is identify the most productive combinations of locally bred varieties and rootstocks adapted to the soil and climatic conditions of the region, ensuring an increase in the efficiency of horticulture in the Middle Volga region. The features of the growth and development of apple trees in combinations of various varieties and clone rootstocks of different growth strengths were studied and the productivity indicators of stock-scion combinations of apple trees in a young fruit-bearing orchard were determined. In the studied stock-scion combinations, the Kuibyshevskoe variety had the maximum projection area, crown volume, and cross-sectional area of the stamb provided by rootstocks 64-143 and Ural 14, the Spartak variety – Ural 8, and the Zhigulevskoe variety – Ural 14. The minimum development of the crown in its horizontal projection and the least development of the garden area by the crowns were in the Kuibyshevskoe and Spartak varieties on the Ural 2 rootstock, and in the Zhigulevskoe variety on the Ural 8 rootstock. According to the productivity of one tree, the Kuibyshevskoe variety had combinations with rootstocks 64-143 (14.2 kg/tree) and Ural 14 (11.4 kg/ tree). The Spartak variety had the most productive trees on the Ural 14 rootstocks (6.7 kg/tree). The most productive combinations of the Zhigulevskoe variety were with the Ural 2 (4.7 kg/tree) and Ural 14 (4.6 kg/tree) rootstocks. The productivity of one tree depended most on the rootstock and the interaction of the variety and the rootstock. In general, according to a set of indicators (productivity per 1 m² of crown projection area, 1 m³ of crown volume, 1 cm² of stamb cross-sectional area), combinations of Kuibyshevskoe variety with rootstocks 64-143 and Ural 14, Spartak variety with rootstock Ural 14, Zhigulevskoe variety with rootstocks Ural 2 and Ural 14 stood out the most.

The purpose of the research – is to perform an experimental assessment of the lubricity of rapeseed and camelina biokerosene based on the results of tribological tests on a TU four-ball tribometer and an HFRR apparatus. The global trend in achieving carbon neutrality is the reduction of harmful emissions from land transport vehicles contained in exhaust gases and generated during the combustion of hydrocarbon fuels in internal combustion engines, through the wider use of alternative motor fuels with a small carbon footprint. For the Russian Federation, with its huge reserves of hydrocarbon raw materials, at the present stage of economic development, a smooth energy transition from traditional types of hydrocarbon-based motor fuel to alternative fuels is advisable. A promising alternative motor fuel for transport diesel engines is biokerosene, which is a fuel composition based on aviation kerosene with the addition of vegetable oil and a cetane-increasing additive in a certain amount. Therefore, there is a need to experimentally determine not only the indicators of the basic physicochemical and operational properties (density, viscosity, cetane number, lower calorific value, fractional composition, fluidity, environmental friendliness, etc.) of biokerosene, but also its lubricity. For this purpose, comparative tribological tests of friction prototypes were carried out using a TU tribometer and an HFRR apparatus using the average wear spot of balls in four lubricating media: petroleum summer diesel fuel, aviation kerosene and biokerosene obtained by adding rapeseed and camelina oils to aviation kerosene.

The purpose of the study is to improve the quality of the technological process of longline tillage. For deep tillage in many countries, simple and reliable tools with a frame on support wheels and several ripping organs are used. A ripper with a straight or curved rack and a chisel is typical. According to agrotechnical requirements, the top layer of soil is cut off and laid at the bottom of the furrow, then the bottom layer is placed on top. Samara Agrarian University has developed a method of tillage with simultaneous loosening of the lower part and the under-arable layers, followed by a turnover of the lower layer. To implement this method, a combined plow was created, consisting of a frame and working bodies of the upper and lower tiers. The section of the combined plow includes a ploughshare body of the upper and a ploughshareless body of the lower tiers. The quality of treatment was assessed by the completeness and depth of embedding of weed seeds and the quality of soil crumbling. The analysis was carried out by layers. The samples were taken with a nine-fold repetition. The research was carried out in the fields of the Volga Scientific Research Institute of Breeding and Seed Production. Plowing was carried out by tractors T-150K and HTZ-16131. The tests were carried out in areas with an inclination angle of no more than 2 °. The soil on the site was homogeneous. Plowing with a serial ploughshare of the STUMP-4-42 led to a ridge on the daytime soil surface exceeding the permissible values of agrotechnical requirements by 0.03 meters. The combined plow improved the situation: the ridge was 0.052 meters, which meets the requirements. The combined plow makes it possible to improve the quality of tillage: improve soil crumbling, reduce rippling and increase the depth of embedding of plant residues. As the processing depth increases, the quality of the crumbling decreases, but better results are achieved at higher operating speeds. The average height of the ridges after processing with a combined plow is 0.052 meters, and the amount of embedded residues is 97.7-98.8%. The depth of their embedding exceeds 0.18 meters, and the degree of crumbling meets agrotechnical requirements.

The purpose of the research – improvement of metabolism in the body of young pigs under the influence of feed additives Tetra+ and Glimalask, introduced into the diet during the fattening period of animals. The biological value of diets affects the level of metabolism and productive qualities, which is important to consider when conducting modern livestock farming. A scientific and economic experiment was carried out on 3 groups of young pigs during fattening. Large white breed pigs were used in the experiment. In the main period of the experiment, the young animals of the control group were given the basic diet (BR), consisting in the 1st period of fattening - from SK-6 and in the 2nd period - from SK-7. Animals of the 1st experimental group were fed Tetra+ in addition to OP in the amount of 40 g per 1 kg of feed, 2 experimental groups in addition to the OP - Glimalask at a dose of 40 mg per 1 kg of feed. Against the background of scientific and economic experience, studies were carried out to study the balance in the body of nitrogen and mineral elements: calcium and phosphorus in pigs. Research has established that in animals of all groups the balance of nitrogen, calcium and phosphorus was positive. However, young animals of the 1st and 2nd experimental groups, compared with the control, had more nitrogen deposits in the body, respectively - by 11.8 and 9.6%; calcium - 3.9 and 1.9%; phosphorus - 17.4 and 1.4%.
A higher level of metabolism in pigs of the experimental groups had a beneficial effect on productive qualities. Young animals of experimental groups 1 and 2 had higher growth energy, as well as slaughter yield indicators, respectively - by 2.1 and 1.7%, meat weight - by 11.35 and 6.35%. The best results for the studied parameters in pigs were found when Tetra+ was used in addition to the main diet.

The purpose of the research is to evaluate the influence of the Mandolong breed gene pool on the productive and biological qualities of Kalmyk beef cattle. The main disadvantage of Kalmyk cattle is a weakly muscled hip part of the trunk and intense fat deposition at an early age. To eliminate the problem, it was decided to ask for the blood of the Mandolong breed, which is recognized as one of the best modern meat breeds. The main problem when crossing Kalmyk and Mandolong breeds to obtain first-generation (F1) crossbreeds is the large body weight of newborn calves, since the Mandolong breed is more than twice the live weight of the Kalmyk breed. The difference in live weight of F1 hybrid bulls, compared with the Kalmyk breed, was 7.3 kg (27.8%; P<0.001), F1 "in itself" – 6.2 kg (23.6%; P<0.001). The growth of mongrel bulls in all age periods was more intense than that of purebred peers of the Kalmyk breed. As a result, live pregnancy at the age of 8 months. it was higher in F1 crossbreeds – by 59.5 kg (23.9%; P<0.001), in F1 crossbreeds "in itself" – by 50.2 kg (20.2%; P<0.001), at the age of 12 months, respectively, by 71.2 kg (20.3%; P<0.001)
and 63.4 kg (18.1%; P<0.001), at the age of 15 months – by 86.2 kg (20.2%; P<0.001) and 73.4 kg (17.2%; P<0.001), at the age of 18 months – by 102.2 kg (20.6%; P<0.001) and 88.7 kg (17.9%; P<0.001). F1 crossbreeds significantly outperform purebred peers in all major body measurements, which characterizes a higher intensity of their growth and development, while the difference between F1 crossbreeds was not statistically significant. A slight decrease in the intensity of growth in crossbreeds during self-breeding can be explained by the use of young bulls that are untested in the quality of offspring.

The aim of the research is to evaluate the activity of enzymatic antioxidants in bull sperm after thawing, in order to understand the molecular mechanisms of reducing the fertilizing ability of sperm during cryopreservation/thawing. The object of the study was the sperm production of black-and-white Holstein bulls at the age of 3 years. The sperm was diluted with a sterile BioXcell medium. The same ejaculate was subjected to two treatments: fresh – evaluated immediately after adding diluent at 37°C and defrosted – evaluated 60 and 120 minutes after defrosting. The intensity of free radical processes in spermatozoa was determined by determining the concentration of malondialdehyde in cells. The effectiveness of the enzymatic link of the antioxidant system was determined by changes in the activity of superoxide dismutase and catalase. Based on the conducted studies, it was found that after cryopreservation, the content of malondialdehyde was higher by an average of 25%. The antioxidant potential of superoxide dismutase after cryopreservation did not depend on the incubation period and increased by an average of 23%, the activity of catalase after freezing / thawing of sperm did not change. Assessing the level of oxidative stress and the activity of the antioxidant system is important for understanding the molecular mechanisms associated with a decrease in cattle productivity.

The article describes a clinical case of hemangiosarcoma treatment in a 7-year-old Labrador dog, local tumor control using intravenous bleomycin and subsequent tumor removal, as well as combined administration of calcium gluconate directly into the area of the tumor node. Hemangiosarcoma is a malignant tumor that is quite common in dogs in middle and older age. Labradors, German Shepherds, and Retrievers are the most susceptible to this disease. The causes of the identified cancer are not yet known, but it is safe to say that the main organs that are affected more often in an animal are the spleen, right atrium, skin and subcutaneous tissue, omentum, mesentery, liver. In 25% of dogs with a spleen tumor, the heart is affected. Tumors affecting only the epithelium of the skin are conditionally malignant. Less often – lungs, kidneys, mouth, muscles, bones, bladder, left ventricle, adrenal glands, brain, diaphragm, peritoneum, lymph nodes, tongue and fingers. Hemangiosarcoma is a highly aggressive tumor that metastasizes hematogenously or implantationally. Dogs without treatment live up to 3 months, with treatment – up to 6 months, 10% of patients survive a year. Along with the treatment of hemangiosarcoma, the diagnostic process is described, since the main problem is to differentiate hematoma - hemangioma – hemangiosarcoma. The difficulty lies in the fact that cytological examination is uninformative due to dilution of the sample with blood, and fine needle aspiration biopsy often gives false negative results, since there are extensive areas of hematomas and normal blood vessels inside the tumor. As a result of the research, the authors reduced the volume of tumor masses by 70% due to the use of electrochemotherapy procedure "Bleomecin" and eletroporation with calcium glucanate.