Mastitis is one of the most common diseases of dairy cows, affecting the udder health, the quantity and quality of milk produced. Early detection of the disease can reduce the cost of treatment, maintain the health and milk production of animals. To diagnose subclinical and clinical forms of mastitis and study their effect on productivity, the authors monitored the udder surface temperature in healthy and sick animals. The research involved about 200 milking purebred cows of the Yaroslavl breed, among which pairs-analogues were selected in accordance with the requirements of OST 70.20.2-80 "Milking installations for cows. Program and test methods". One animal from the pair was in the experimental group, and the other was in the control group. The productivity of animals in pairs did not differ by more than + 5% (in a healthy state). Animals in the studied groups were in the third or fourth month of lactation. Animal productivity was assessed once a month by conducting control milkings. Thermal imaging studies were carried out on a working dairy farm using a Guide C400M thermal imager operating in the infrared range with an image resolution of 384 x 288. As a result of the studies, thermograms of the udder surface temperature in diseased animals and their healthy counterparts were analyzed and the following udder temperature ranges were identified: 32...35°C - in healthy animals with a negative test for mastitis; 36...37°C - in animals with a subclinical form of mastitis; 38...39°C - in animals with a clinical form of mastitis. For sick animals, the extremely high relationship between the critical increase in udder surface temperature and milk yields was confirmed by the linear Pearson correlation coefficient. The conclusion was made that the use of infrared thermography to determine the temperature thresholds of the udder is a fast and non-invasive way to obtain reliable information about an animal's health and productivity.

Comfortable keeping of animals directly affects their productivity. The authors analyzed the parameters of comfort for animals in loose housing: ambient temperature, relative humidity in the barn, stall bedding and standards for arranging passageways, feeding and watering areas. Studies have shown that the comfortable keeping of animals requires a number of parameters: temperature in the barn within 0...+12°C; sufficient space - at least 30 cub. m of space per animal; the box width of about 1.10...1.20 m; air exchange rates in winter of 4...5, in summer - of up to 20...30; stall bedding - sand or a rubber filling mattress. The optimal temperature and humidity index for adult cattle should be at least 68. To comply with all technological standards for the comfortable keeping of animals, the authors suggest using unified fasteners to adjust the width of the stall space to the required distance depending on the cow's body weight, set the overhead bar to ensure a convenient animal position, and change the location of the chest board. Compliance with the basic parameters of animal keeping and a possibility of adjusting the dividers for boxes make comfortable conditions for the animal to lie down and chew food longer, which contributes to an increase in the milk yield.

The authors studied the model of an axial-rotary threshing-and-separating unit (RF Patent No. 1665246) to expand the technological capabilities and adapt it to the changing conditions of grain harvesting. In the developed unit, the cage parts (a feeder, a threshing and separating part, a straw separating part and a straw unloading part) are freely connected with one another and can rotate independently. The unit also provides changing rotation speed of the cage parts relative to the rotor as they counter-rotate, co-rotate, or are at a complete stop. The study results describing the threshing and separation of the Rostovchanka and Severodonskaya wheat varieties and lupine-grass mixed crops with different moisture content can prove the validity of the developed scheme with independent rotation of the cage parts. The treshing and separation of the Rostovchanka and Severodonskaya wheat varieties and mixed lupine-grass crops were studied at grain moisture content of 9.6...13.0°/o, straw moisture content of 10.3...15.0%, ratio of grain-to-straw mass of 1:1.6...1.8. The authors have found that the operation of the rotor and the rotating cage in each separate part of the threshing unit has an impact on the threshing process. The best capacity results of the axial-flow threshing-and-separating unit are obtained when the rotor, the feeder cage and the threshing and separating cage co-rotate, or when the rotor and the cage of the straw separating part counter-rotate. The study has revealed that an effective separation and the least grain crushing are observed at a cage rotation speed of 28...42 min^-1, a rotor speed of 870...1000 min^-1, and set feed rates of 8.5...12.3 kg/s. The developed design provides more intensive operation of the threshing-and-separating unit, due to the increased number of the options for adjusting the thresher, and also facilitates cleaning the separating gratings and prevents stem mass bundling.

An increase in the productivity of pneumatic systems of grain cleaners is achieved by increasing the size and number of pneumatic separating channels. But as the channel depth increases, the non-uniformity of the air flow velocity field in the separation zone increases too, and an uneven air flow is formed in the outlet of the pneumatic separating channel, due to the action of centrifugal forces, which negatively affects the quality of grain cleaning. The purpose of the study is to improve the quality of grain material cleaning with an air-separating device of a grain pre-cleaner by equalizing the air flow in the upper part and the front part of the air-separating channel outlet by installing a guide vane in the outlet and optimizing its parameters. The authors measured the air flow rates in the pneumatic separating channel and its outlet in the idle mode at the laboratory installation of the pneumatic system of a grain pre-cleaner, as well as analyzed the cleaning of the artificially prepared grain mixture with a moisture content of 14%, consisting of barley grain of the Zazersky variety (95%) and light impurities (5%). The specific supply of grain material to the pneumoseparating channel corresponded to 7.94 kg/(s•m), the loss of valuable grain to waste was 0.05%. As a result of an aerodynamic study of the pneumatic separating channel outlet without a guide vane, a significant non-uniformity of the air flow was established in its initial section: the coefficient of air velocity variation along the channel depth amounted to 0.29, which exceeds the target values (0.20...0.25). Installing a guide vane with optimal parameters contributes to the alignment of the air flow in the upper part of the channel and the front part of its outlet, which has a positive effect on pneumoseparation. With the vane radius of 0.20 m, an angle of its arc of 80°, depths of the inlet and outlet sections of the inner part of the outlet of 0.105 and 0.066 m, respectively, the cleaning effect of the grain material from light impurities increases by 6.6% (from 61.2 to 67.8%).

The use of single-operation and double-operation soil-cultivating tools for main and pre-sowing tillage leads to an increase in agrotechnical terms and the production cost. To combine several operations and increase the economic efficiency of tillage, a multi-operation tillage unit has been developed. The proposed unit is designed in such a way that the working tools are fixed on the racks of the main frame and are located with an overlap on the rear frames. The working tool is a cultivator center hoe, under the wings of which there are slitters mounted on three plates with grooves, corresponding to the parameters of the center hoe wings. One slitter is fixed in the center of the center hoe, and two - on the sides under the wings. Removing the central slitter doubles the distance between the slitters. The authors decided to make a slitter in the form of an arbitrary trapezoid with sides having a different inclination angle to the horizontal surface. It has been experimentally established that the optimal ratio of the frontal area of the slitter to its height is 1:10. The soil-cultivating working tool with the changing angle of its location by 180° and the changing curvature of the cutting edge of the working surface of the slitter can be used in different soil conditions and features the increased service life. It is recommended that pre-sowing cultivation be carried out to a depth of 10 cm. Performing four operations in one cycle by a tillage device: slitting, surface tillage with weed control, the final phase of tillage and surface compaction - ensure the increased economic efficiency of the entire process.

It is difficult to experimentally evaluate the traction and coupling properties of a tractor during its operation, so developing a method for an express analysis of slipping is an urgent practical task. According to GOST, traction properties are estimated against normalized soil backgrounds and the horizontal direction of the traction force vector, which differs significantly from production tests. To justify the methodology for estimating slipping when a machine-tractor unit operating on small-size sample plots, it is proposed to use a differential model. The methodology was tried based on the traction test results of the MTZ-80 tractor on winter wheat stubble and experimental studies of a chisel unit based on the New Holland S8000 tractor. The experiments were carried out for three levels of soil moisture: 11...13; 14...16; 17...19%. The tillage depth was 12...15; 17...20; and 22...25 cm. It has been established that the adequacy dispersions of the obtained dependences of slipping on the tractive effort coefficient for the compared options are practically homogeneous. For soils with a moisture content of 11...13%, the dispersion of adequacy is 0.117, for a moisture content of 14...16% - 0.637, for a moisture content of 17...19% - 0.827. With low soil moisture, the interaction of a wheel with the soil is more stable. The authors conclude that the method of express analysis of tractor wheel slipping when performing specific types of work, with a limited amount of experimental data, makes it possible to obtain dependences comparable in accuracy with the data of traction tests.

When cultivating corn, large farm holdings use a wide range of various modern herbicides to control weeds. For many small farms, herbicidal weeding of crops is practically impossible due to expensive inputs. To minimize corn production costs, the author analyzed the effectiveness of combining cultivator working tools for row-to-row processing of corn crops. The experiment was conducted in the Tambovka district of the Amur region. A "Bereginya" seeder was used to sow medium-ripened Falcon maize (hybrid). The seeding rate was 80...90 thousand germinating grains per 1 ha. The seeding depth was 4...6 cm. The cultivation operations involved pre-emergence harrowing and cultivation. To combat weeds and loosen the soil, two inter-row treatments were carried out during the phase of the first- and fifth-leaf formation. The experiment included four combinations of cultivator working tools: flat hoes (blades), universal center hoes, chisel-shaped hoes and hoe wheels. A variant with the use of a herbicide mix was adopted as the standard. The tillage depth with one-sided flat hoes (blades) was 6...8 cm, with universal center hoes - 10...12 cm, with chisel-shaped hoes - 15...20 cm, with hoe whells - 8...10 cm. It was experimentally established that the use of a herbicide mix contributed to obtaining the highest corn yield of 3.87 t/ha. Mechanical weeding of row spacing using two universal center hoes with a chisel-shaped hoe and hoe wheels or two one-sided flat hoes with a center hoe made it possible to obtain yields of 3.39 and 3.38 t /ha, respectively, and increase the profitability of corn production by 3.8...38.6%o as compared with the use of a herbicide mix. The study has proved the effectiveness of combining cultivator working tools in inter-row cultivation of corn crops.

Due to the change in the retirement age and the increase in the proportion of elderly tractor drivers in agricultural enterprises, it became possible to increase the number of emergencies and accidents in the field. The methodological basis of the research was the study and analysis of changes in human cognitive abilities with the increasing age (decreased attention, memory, and performance) and operating environment factors of tractor drivers that affect their fatigue and performance. It has been established that the risks of increased number of emergencies and accidents may grow due to natural biological processes occurring in the body of most people after reaching the age of 60. The age-related decline in attention, memory, decision-making speed, and efficiency of elderly tractor drivers can be aggravated by the presence of harmful production factors in the workplace. At the same time, over many years of work in unfavorable sanitary and hygienic conditions, the risks of occupational diseases may also increase. The author draws conclusions about the need for agricultural managers to adjust the system of both assessing occupational risks and managing the health and safety of elderly tractor drivers. It is advisable for the labor protection services of agricultural enterprises to develop and implement a system for managing the risks of overwork, organizing fatigue preventive measures for elderly tractor drivers and, accordingly, the probability of various incidents and accidents. It is necessary to conduct research on the combined effect of microclimate and noise parameters on the fatigue, reaction speed, and attentiveness of elderly tractor drivers to develop requirements for their work and rest modes and clarify the requirements for the arrangement of tractor cabs and mobile agricultural machines.

The fault inspection of the main parts of gearboxes aims to determine their technical condition and assess the degree of wear of the working surfaces and the possibility of their further use. In the process of fault inspection, parts are usually sorted into three groups: fit, unfit (irrepairable reject) and requiring repair (recoverable reject). The parts are separated into particular groups based on the measurement results of controlled parameters obtained using selected optimal measuring instruments (a micrometer, a caliper, an indicator, etc.). The authors have carried out a study of the dimensions of new and worn parts forming the 040H7/k6 "shaft-to-gear bushing" connections used in farm machinery gearboxes. It has been found that the hole size defect amounts to 12.45%, and the shaft size defect is 8.69%. The study has revealed that the greatest wear of the holes reaches 0.082 mm, about 19% of gears are subject to replacement during repair due to their enlarged internal diameter, the shafts wear out to 0.12 mm, and about 23% of the shafts are defective. The authors have shown that a new connection has a transitional fit, as evidenced by the presence of both gaps and tightnesses, the latter prevailing. The reject is 0.91% to the left of the fit tolerance and 0.47% - to the right. This indicates that all new holes and shafts can be allowed for assembly, including those that turned out to be defective, but the resulting connection will be practicaly defectless. When connections are formed from worn parts, more than 25% of defects are due to the largest gap; therefore, fault inspection and continuous monitoring are necessary in this case. The article shows that the inspection analysis of parts in case of defects must be carried out taking into account the quality assurance parameters of the connection assembly.

Further development of mechanical engineering requires new and improved existing technologies, including hardening and restoration of parts, as well as technologies for obtaining functional coatings. Electrical contact welding is an effective method of obtaining functional coatings on the working surfaces of parts for various purposes. The article considers technological capabilities, the experience of using various materials, hardness and wear resistance of coatings obtained during with electrocontact welding. The authors consider the main technological equipment and make recommendations on choosing the suitale tools. The article presents a classification of the processes of obtaining functional coatings by electrocontact welding, taking into account their physical and technological features. Based on this classification, one can make a rational choice of the kind and type of equipment to be used, the process algorithm, the filler materials, as well as the means of process intensification based on the needs and capabilities of a particular production process.

The agro-industrial sector is currently experiencing a shortage of personnel. Despite the fact that agriculture has radically changed in terms of technologies and methods of production, many people still consider farm-related jobs tedious, consumptive, monotonous, and thus unattractive. Unmotivated schoolchildren with low USE scores often enter agricultural universities. "Agroclasses" is one of the career guidance areas aimed at motivating schoolchildren and forming their readiness for a conscious choice of an agricultural profession. The propaedeutic stage of professional self-determination of schoolchildren is important not only for higher education, but also for secondary vocational education and training (SVET). The SVET objectives are not limited to the training of qualified workers and mid-level specialists. The authors also proved the relevance of the career development trajectory "college-higher education (secondary and tertiary professional training programs)" associated with the problem of teaching content continuity, including "shortened" university curricula. This goal requires modernization of the list of academic curricula of agrarian universities. The competitiveness of higher agrarian education at the stage of technological development "AgroTech 4.0" depends on the implementation of the principles of continuity and succession of professional education through the introduction of flexible module-based inter-disciplinary programs.

The practical skills of agroengineers include the skills of operating technical means used in the agricultural sector. The variety of brands and modifications of training simulators and their functionality creates difficulties in obtaining the full range of skills required fror operating transport and technological machines. To expand the practical skills of students, the authors conducted analytical and patent studies of training simulators. As a result, they present a simulator using the technology of augmented reality terrain emulation, which can simulate dynamic force effects on the vehicle cab, when driving at a uniform speed on roads with different surface profiles and rotation angles, displaying the dynamics of translational motion with visual images. The impact of the vertical road terrain on the vehicle and the operator's cabin is simulated by four vertical linear pneumatic actuators acting on the inclined platform using control devices, by means of short-term lifting and the return movement of the rods. The lifting height is modeled by the pressure in the receiver and the duration of the open state of the valve and is consistent with the road relief-modeling program. With the controls, the trainee simulates the control of the vehicle movement along the road. The central microprocessor device displays an image of the road with a visible profile of rhe vehicle's body part and the trainee, who feels the dynamic effect on the receptor-muscular system through mechanical movements of the simulator cabin, creates a psychophysical perception of the full range of real control factors over the machine. The proposed prototype of the training simulator for the movement of a technological vehicle will increase the effectiveness of training operating skills.

The article considers the features of the implementation of a practice-oriented approach in organizing the training of secondary vocational education (college) students. The modern economy puts forward requirements for improving the quality of training of college graduates, and therefore it is necessary to modernize professional education, including the introduction of adaptive, practice-oriented, and flexible training programs. The use of a practice-oriented approach requires a change in the content and methodological aspects of education, which will entail a reorientation of the training process from transferring mainly knowledge and ideas to students to developing their skills to carry out practical actions, acquire and accumulate skills and experience of practical work in their chosen field of activity. For this purpose, first of all, it is necessary to develop cooperation between educational institutions of secondary vocational education and employers, i.e. establish a system of dual education, which can be considered as the leading pedagogical condition for the modernization of practical training. Along with this, important conditions also include: improving the material and technical equipment of the educational process to synchronize it with the demands of manufacturing enterprises; advanced training of teachers who implement practical training of students and diagnosing the development of their professional competences; organization of students' participation in competitions of professional skills and olympiads; improving the content and methodology of production practices as the top line in practical training; promoting the employment of college graduates. The features of the implementation of these pedagogical conditions are exemplified by the experience of Polytechnic College No.8 named after twice Hero of the Soviet Union I.F. Pavlov (Moscow).