Microclimate is a complex of physical environmental factors in a limited space that influences the body’s heat metabolism.
In animal husbandry, microclimate is understood, first of all, as the climate of premises for animals, which is defined as the totality of the physical state of the air environment, its gas, microbial and dust pollution, taking into account the condition of the building itself and technological equipment. In other words, microclimate is the meteorological regime of enclosed spaces for animals, the concept of which includes temperature, humidity, chemical composition and air speed, dust content, illumination, etc. An optimal microclimate helps to increase animal productivity and reduce feed consumption per unit of production. , has a positive effect on maintaining the health of animals.
The factors that shape the microclimate in agricultural premises include:
local (zonal) climate, weather conditions and time of year;
thermal and humidity resistance of building envelopes;
the state of ventilation, sewerage, quality of manure removal, degree of lighting and heating;
animal keeping technology;
type of animals and their density;
quantity and quality.
Zoohygienic requirements for the microclimate parameters of livestock premises.
Keeping horses in a stable is inevitably associated with air pollution; with poor ventilation, this adversely affects the health of the animals. The air exchange through windows and gates is insufficient. Therefore, the stable must have ventilation - natural supply and exhaust or forced. However, with free air circulation, drafts should be avoided, otherwise sweaty animals after work, as well as foals, can easily catch a cold.
In some stables, during construction, a gap is left between the roof and the upper crowns of the walls: this technique allows stagnant air to evaporate, but eliminates drafts. But most often, stables are equipped with supply and exhaust ventilation with natural impulse.
The size of the exhaust pipe is at least 0.8 × 0.8 m, and the supply channel is 0.2 × 0.2 m. One pipe is equipped for every 12-15 horses. However, to more accurately determine the number of pipes, the volume of ventilation is calculated by air humidity or carbon dioxide (depending on the characteristics of the climatic zone). This ventilation works satisfactorily at sub-zero outside temperatures, but is ineffective at elevated temperatures. Exhaust pipes are equipped with deflectors in their upper part, and dampers are installed in the lower part to regulate the air being removed. The permissible air exchange - at least 17 m³ per hundredweight of the horse - is reduced during the cold period minimally to the limits necessary to maintain the temperature of the room, without normalizing its relative humidity.
In winter, the air temperature in the stable can drop to 4 degrees and even be below zero, but if there are no drafts, then both adult horses and foals will safely withstand it.
To heat the stables in damp and cold seasons, you can install central heating, use safe heaters (when warm air flows through pipes) or heat guns.
Microclimate optimization includes compliance with technological design standards during the construction of buildings, as well as constant monitoring of the main climatic parameters of the internal environment of livestock buildings.
In addition, to protect against the introduction of infectious agents and improve sanitary and hygienic conditions in the territory of livestock buildings, the following measures are carried out. The territory is surrounded by a fence no less than 1.8 m high and landscaped in 3-5 rows with trees and shrubs. Local plant species are selected for plantings, taking into account their sanitary, protective and decorative properties and resistance to industrial emissions. In the green areas in the summer months, the temperature is 2-2.5 °C lower compared to open areas, and the air movement speed is reduced by 60-80%, the amount of dust and microorganisms is reduced by 50-60%. Under these conditions, animals’ cardiac activity, breathing, gas exchange and heat exchange are normalized, and natural resistance and productivity are increased.
To protect livestock buildings from prevailing winds, sand and snow drifts, trees and shrubs are planted on the side of these winds, along the borders of the buildings, along internal roads, veterinary buildings and between buildings. Green spaces protect animal premises from overheating (in summer) and cooling (in winter), which helps improve their microclimate.
MINISTRY OF RURAL farms
ALTAI STATE AGRICULTURAL UNIVERSITY site
Department of Cattle and Horse Breeding
Course work
Microclimate in livestock buildings
Completed by: Udartseva Yu.V.
Checked by: Goncharova L.N.
Barnaul 2010
Introduction
- Literature review
1.2 The influence of microclimate on the health of animals and birds
1.3 Protection measures environment
- Brief characteristics of the farm and sanitary and hygienic assessment of the farm
4. Characteristics of a separate livestock farm, complex
5. Dimensions of buildings, sections, equipment
6. Technology of labor-intensive processes
7. Ventilation system
7.1 Natural
7.2 Artificial
8. Room heating systems
9. Room illumination
9.1 Natural light
9.2 Artificial lighting
10. Graphic part
11. Measures to improve the operation of premises and technological equipment
Conclusion
Bibliography
Introduction
Maintaining high productivity of animals and ensuring veterinary well-being on farms is impossible without observing the rules of hygiene in keeping, feeding, caring for, raising young animals and maintaining premises. Farm animal hygiene is a veterinary science about the prevention of stressful situations on the animal body, depending on climatic, meteorological, soil factors, feeding conditions, maintenance, and technological solutions for buildings included in the projects. Animal hygiene begins with the protection of livestock facilities from the introduction of infections and ends with the development of measures for the disposal of production waste; it prevents the aerogenic spread of microorganisms, develops veterinary gaps and sanitary protection zones; forms the principles of filling and emptying premises, preventive breaks in sections, determines the number of animals in sections and premises, as well as optimal conditions for keeping, feeding, watering and caring for animals to obtain from them environmentally friendly, safe for humans products that meet modern regulations and GOSTs .
Veterinary hygiene is based on disease prevention, taking into account the ecological chain “air - soil - water - feed - animals - products - environmental protection - people”. Breaking this chain leads to irreparable consequences for both animal and human health. Therefore, all zoohygienic standards are coordinated with the State Sanitary and Epidemiological Service. Animal hygiene cannot be separated from veterinary sanitation, which includes measures for disinfection, deratization, etc., thereby facilitating compliance with animal hygiene standards.
Zoohygienic standards are developed by a number of scientific institutions (Giproniselkhoz, VNKIVSGE, VIZH, VIGIS, MGUPB and others), approved by the bureau of the departments of veterinary medicine and zootechnics of the Russian Academy of Agricultural Sciences, and then included in the “Departmental Standards of Technological Design” for animal species. Taking into account these VNTP, design institutes develop individual and standard projects for the construction, reconstruction and operation of farms.
To date, such standards have been developed for all types of farm animals, including those kept on farms. Animal health specialists participate in the development of design assignments and in the preparation of projects, in their examination, selection of areas for construction and acceptance of objects into operation; completing farms, quarantining, transporting animals.
In accordance with veterinary and sanitary rules and zoohygienic standards, any farm must operate on the “closed type” principle, be fenced, landscaped, divided into “black and white” zones, have a sanitary checkpoint, disinfection barriers and disinfection mats at the entrance to the territory and the entrance to the premises. All production processes on the farm they must go “front-to-back”, without crossing paths when regrouping animals and operating transport. Most premises, especially for young animals, must be operated according to the principle “everything is free - everything is occupied”, preventive breaks must be observed to carry out a set of veterinary and sanitary measures (cleaning, repairs, washing, disinfection with the provision of “biological rest”).
The farm itself, depending on the quantity, type and age groups animals must be provided with veterinary facilities: a veterinary center, an isolation ward, a quarantine, a slaughterhouse or a slaughterhouse, and have containers for collecting corpses and confiscated goods. All corpses must be taken to veterinary and sanitary plants, and only in their absence is disposal in biothermal pits allowed.
The qualifications of workers play a huge role in maintaining animal health and obtaining quality products. Therefore, livestock specialists and veterinarians must constantly conduct veterinary education with their staff, using materials on this topic.
1. Literature review
1.1 The importance of microclimate and factors of its formation
A natural sequence of atmospheric phenomena created in a given area as a result of long-term exposure to solar radiation, soil, movement air masses The conditions that determine a characteristic weather regime or a set of weather conditions observed over a long period of time in this area are called climate.
The climate of a particular area, as opposed to the weather, is more stable. Each geographical area characterized by its characteristic climatic features.
The climate of large geographical areas is called macroclimate. Conversely, the climate of a confined space includes the concept of microclimate.
In animal husbandry, microclimate is understood, first of all, as the climate of premises for animals, which is defined as the totality of the physical state of the air environment, its gas, microbial and dust contamination, taking into account the condition of the building itself and technological equipment.
Microclimate - indoor climate. It is of great importance for the formation of the animal’s constitution, its productivity and resistance.
The microclimate is composed of several parameters, temperature, humidity, lighting, air speed, gas composition of the air. Failure to comply with these parameters, at least one of them, will lead to pathological changes in the body. However, the significance and quantitative value of each of them depends on the purpose of the agricultural building and the animals that will be located in them. For certain groups of animals, one or another microclimate parameter will be more significant or, conversely, almost neutral. A number of specialists are involved in creating an optimal microclimate: livestock specialist, veterinarian, builders, engineers, mechanics and, as the final link in this chain, technical personnel, but the main role undoubtedly belongs to animal health specialists.
The formation of the microclimate in animal premises is significantly influenced by the local climate, the season of the year, the thermal and humid state of the surrounding building structures, the ventilation device and the level of air exchange, heating, sewerage, methods of cleaning and removing manure from the premises, lighting, as well as technology for keeping animals, density and placement, daily routine on the farm, type of feeding, methods of feed distribution, watering, etc. The construction, operational and design features of the building have a great influence. The terrain, as much as it can improve the microclimate, can worsen it by the same amount. The formation of microclimate is also determined by remoteness livestock farms from industrial enterprises and settlements, protection from the prevailing cold winds. Of considerable importance is the depth of groundwater and the location of the building to the cardinal points. Quite a lot important has an internal layout of buildings, area and cubic capacity per head, as well as the number of rows of stalls, pens, cages, sections, feed and manure passages, the presence of vestibules and a thermal curtain in them, the use of infrared irradiators for young animals, insulation of doors, size and the number of windows and their glazing. The construction of floors is important, since heat loss from 20 to 40% of all heat loss occurs through the floor; the incidence of colds in animals depends on the quality of the floor.
1.2 The influence of microclimate on the health of animals and birds
1.3 Measures to protect the environment
The main environmental issues are the disposal and storage of manure. When choosing a place to store manure, first of all, you need to take into account the climatic conditions of the area. As a rule, a manure storage facility is located on the leeward side of the farm. However, the most well-known way to dispose of manure is to apply it to fields as fertilizer. Thanks to the application of manure, the physical and chemical composition of the soil improves and fertility increases. The manure storage facility must be built in such places that the access of animals is excluded and the access of people is limited, since various pathogens may be present in the manure. Manure from isolators and quarantines must be collected and stored for 30 days in separate manure storage facilities or on concrete sites located in the yard of the isolation facility or quarantine. Disinfection, disposal and transportation of such manure is carried out in accordance with veterinary legislation.
It is necessary to provide for agricultural fields and irrigation of agricultural crops. Usage Wastewater for irrigation is not allowed in areas with standing groundwater at a depth of less than 1.25 m.
Animal corpses are transported to a collection point for raw materials to be sent to a plant for the production of meat and bone meal. From the collection points for raw materials, the corpses are transported to the veterinary and sanitary plant for the production of meat and bone meal in special machines of the plant. If there are no such factories, then groups of animals, as directed by the veterinarian, are disposed of in special trays in the disposal department of the slaughterhouse, with subsequent feeding to animals of another species or obtaining technical products. The corpses of animals that died from particularly dangerous diseases are burned in special workshops.
In order to protect the air, measures are taken to plant green plants along the perimeter and between buildings, which helps reduce air pollution by 3-5 times; compliance with veterinary and sanitary gaps between buildings (20-25m), buildings are located parallel to the prevailing winds so that polluted air is blown out of the farm territory. The intake of clean air is carried out from below from the end of the building, the exhaust is carried out upward, it is also necessary to maintain a veterinary and sanitary gap between the farm territory and the populated area, the manure storage facility.
2. Brief description of the farm
LLC “Zapadnoye” was formed in 1957. The central estate of the state farm is located three kilometers from the regional center of Klyuchi. The distance to the regional center of Barnaul is 370 km.
According to agroclimatic zoning Altai Territory The farm is located in a warm, dry area. In general, climatic conditions are favorable for growing crops. The climate is characterized by hot but short summers and cold winters with strong winds and snowstorms. The average air temperature in summer is +20+25C, the maximum temperature is +40+41C. The average air temperature in winter is -16-20C, the absolute minimum temperature is -40-41C.
Geomorphologically, the territory of the state farm is a flat, ridged plain with a small number of depressions occupied by lakes. The hydrographic network on the territory of the state farm is represented by lakes. The water of the lakes is suitable for watering livestock and for household needs.
The direction of production activity of the farm is cattle breeding with developed grain production.
The total land area of the farm is 21,342 hectares, of which arable land is 15,470 hectares, hayfields are 1,167 hectares, pastures are 2,756 hectares, and cattle are 800 heads.
The cattle farm is located 1500m from the road. Summer camps located at a distance of 300m from the complex, that is, 1800m to the village.
3. Zoohygienic requirements for choosing a site for the construction of livestock buildings
The land plot for the construction of livestock farms must meet zoohygienic requirements. The correct choice of site for their construction is of great importance for the production activities of farms and complexes. A well-chosen site allows for better use of forage lands and reserves, clearly organizing technological processes and the work of service personnel, rational transportation of feed, manure, animals, etc., correctly marking out the buildings and structures included in the farm, and, as necessary, expanding and developing the farm. .
When choosing sites for the construction of livestock farms and complexes, it is necessary to maintain the distance to roads. Here it is necessary to take into account both the necessary veterinary and sanitary gap, which ensures the possibility of localizing the work of the enterprise, and the convenience of transport connections with the main roads along which feed is imported and products are exported.
Veterinary gaps from complexes to highways of national, republican and regional significance of categories I and II must be at least 300 m, to highways of republican and regional significance of category III to cattle drives - at least 150m, to other highways of local significance - not less than 50m, with the exception of access roads to the enterprise.
You cannot build on a site with close groundwater.
The land plot must be: dry, not chipped
etc.................
INTRODUCTION………………………………………………………………………………..2
MICROCLIMATE OF LIVESTOCK PREMISES………………..3
INFLUENCE OF THE CHEMICAL COMPOSITION OF AIR ON THE PRODUCTIVITY OF FARM ANIMALS………..6
INFLUENCE OF PHYSICAL PROPERTIES OF AIR ON THE BODY
ANIMAL………………………………………………………………………………..8
CONCLUSION………………………………………………………………………………….10
LIST OF REFERENCES……………………………………...11
INTRODUCTION
Keeping farm animals in closed
in the premises of industrial livestock farms is associated with significant deviations of the parameters and gas composition of the air from normal conditions. Therefore, when designing livestock complexes, along with theoretical dependencies, experimental data obtained from experimental studies are usually used. Experiments to determine the influence of environmental parameters on the condition of animals and the biological changes occurring in their bodies under the influence of these parameters are carried out by scientists from domestic and foreign research centers. Under natural conditions, frequent and unexpected weather changes significantly complicate experimental work, resulting in an increase in the duration of research. The time required for conducting experimental research can be reduced by creating an artificial climate that simulates the conditions of a particular season. Such conditions can be created in a special installation consisting of a climate chamber, animal life support systems and control of machines and devices. It serves as a physical model of a livestock building and allows for research on farm animals in laboratory conditions.
Microclimate of livestock premises.
The microclimate of livestock premises is the totality of physical and chemical factors of the air environment formed inside these premises. The most important microclimate factors include: temperature and relative humidity of the air, the speed of its movement, the speed of its movement, the chemical composition, as well as the presence of suspended dust particles and microorganisms. When assessing chemical composition air is determined primarily by the content of harmful gases: carbon dioxide, ammonia, hydrogen sulfide, carbon monoxide, the presence of which reduces the body's resistance to disease.
Factors influencing the formation of the microclimate are also: illumination, the temperature of the internal surfaces of enclosing structures, which determines the dew point, the amount of radiant heat exchange between these structures and animals, air ionization, etc.
Zootechnical and sanitary-hygienic requirements for keeping animals and poultry boil down to ensuring that all indicators of the microclimate in the premises are strictly maintained within the established standards.
Table 1. Zootechnical and zoohygienic standards for the microclimate of livestock premises (winter period).
Premises |
speed |
carbon dioxide gas (by volume), % |
Illumination, lux. | ||
| Cowsheds and buildings for young animals | 3 | 85 | 0,5 | 0,25 | 10-20 |
| Veal breeders | 5 | 75 | 0,5 | 0,25 | 10-20 |
| Maternity ward | 10 | 70 | 0,3 | 0,25 | 25-30 |
| Milking parlors | 15 | 70 | 0,3 | 0,25 | 15-25 |
| Pig pens: | |||||
| for single queens | 16 | 70 | 0,3 | 0,25 | 5-7 |
| fatteners | 14 | 75 | 0,3 | 0,3 | 2-3 |
| Sheepfolds for adult sheep | 4 | 80 | 0,5 | 0,3 | 5 |
| Poultry houses for laying hens: | |||||
| floor content | 12 | 65 | 0,3 | 0,2 | 15 |
| cellular content | 16 | 70 | 0,3 | 0,2 | 20-25 |
These standards are established taking into account technological conditions and determine permissible fluctuations in temperature, relative air humidity, air flow speed, and also indicate maximum acceptable content harmful gases in the air.
With proper maintenance of animals and optimal air temperature, the concentration of cloacal gases and the amount of moisture in the air in the room does not exceed permissible values.
In general, processing supply air includes: dust removal, odor removal (deodorization), neutralization (disinfection), heating, humidification, drying, cooling. During development technological scheme supply air treatments strive to make this process the most economical, and automatic regulation the simplest.
In addition, the premises must be dry, warm, well lit and insulated from external noise.
In maintaining microclimate parameters at a level at the level of zootechnical and sanitary-hygienic requirements, an important role is played by the design of doors, gates, and the presence of vestibules, which winter time open when distributing feed with mobile feed dispensers and when removing manure with bulldozers. The premises are often overcooled, and animals suffer from colds.
Of all the microclimate factors, the most important role is played by the air temperature in the room, as well as the temperature of floors and other surfaces, since it directly affects thermoregulation, heat exchange, metabolism in the body and other vital processes.
In practice, indoor microclimate refers to controlled air exchange, i.e., the organized removal of polluted air from the premises and the supply of clean air through the ventilation system. With the help of a ventilation system they support optimal temperature but humidity conditions and chemical composition of air; create in different periods year required air exchange; ensure uniform distribution and circulation of air indoors to prevent the formation of “stagnant zones”; prevent condensation of vapors on the internal surfaces of fences (walls, ceilings, etc.); created in livestock and poultry buildings normal conditions for the work of maintenance personnel.
The air exchange of livestock premises as a calculated characteristic is the specific hourly flow rate, i.e. the supply of supply air, expressed in cubic meters per hour and referred to 100 kg of live weight of animals. Practice has established the minimum acceptable air exchange rates for barns - 17 m 3 / h, calf barns - 20 m 3 / h, pigsties - 15-20 m 3 / h per 100 kg of live weight of the animal located in the room in question.
Illumination is also important factor microclimate. Natural lighting is most valuable for livestock buildings, but in winter, as well as late autumn it's not enough. Normal lighting of livestock premises is ensured subject to the standards of natural and artificial illumination.
Natural lighting is assessed by the luminous coefficient, which expresses the ratio of area window openings to the floor area of the room. Artificial illumination standards are determined by the specific power of lamps per 1 m 2 of floor.
The optimally required parameters of heat, moisture, light, air are not constant and vary within limits that are not always compatible not only with the high productivity of animals and poultry, but sometimes with their health and life. To ensure that the microclimate parameters correspond a certain type, age, productivity and physiological state of animals and poultry at different conditions feeding, maintenance and breeding, it must be regulated using technical means.
Optimal and controlled microclimate are two different concepts, which at the same time are interrelated. An optimal microclimate is a regulated goal and a means to achieve it. The microclimate can be regulated using a set of equipment.
The influence of the chemical composition of air on the productivity of farm animals.
The concentration of vapors from animal excretions in indoor air above the permissible norm has a negative impact on health and productivity. It is measured by gas analyzers.
Animals absorb oxygen and release carbon dioxide and water vapor. 100 volume parts of air (without water vapor) contain: nitrogen 78.13 parts, oxygen 20.06 parts, helium, argon, krypton, neon and other inert (inactive) gases 0.88 parts, carbon dioxide 0.03 parts. At optimal air temperature, a 500-kilogram cow emits 10-15 kg of water vapor per day.
Nitrogen in the air in a gaseous state is not used by animals: the amount of nitrogen they inhale is the same amount they exhale. Of all the gases, animals absorb only oxygen (O2).
Relatively constant atmospheric air and by the content of carbon dioxide (CO 2) in it (fluctuations within 0.025-0.05%). But the air exhaled by animals contains much more of it than the atmosphere. The maximum permissible concentration of CO 2 in livestock yards is 0.25%. Over the course of an hour, a cow emits on average 101-115 liters of carbon dioxide. As the permissible rate increases, the animal’s breathing and pulse become much faster, and this, in turn, negatively affects its health and productivity. Therefore, regular ventilation of premises is important condition normal life.
In the air of poorly ventilated livestock buildings, you can find a fairly significant admixture of ammonia (NH 3) - a gas with a pungent odor. This poisonous gas is formed during the decomposition of urine, feces, and dirty litter. Ammonia has a cauterizing effect during breathing; it easily dissolves in water, is absorbed by the mucous membranes of the nasopharynx, upper respiratory tract, and conjunctiva of the eye, causing severe irritation. In such cases, animals develop coughing, sneezing, lacrimation and other painful phenomena. Acceptable rate ammonia in the air of barnyards is 0.026%.
When feces rot as a result of decomposition in liquid receivers and in other places, hydrogen sulfide (H 2 S) accumulates in the air of rooms with poor ventilation, which is a highly poisonous gas with an odor. rotten eggs. The appearance of hydrogen sulfide in the premises is a signal of poor sanitary condition of livestock premises. As a result, a number of disorders occur in the body: inflammation of the mucous membranes, oxygen starvation, dysfunction nervous system(paralysis of the respiratory center and blood vessel control center), etc.
Influence physical properties air on the animal's body.
Ambient temperature has a huge impact on the body, in particular on the heat generation processes that constantly occur in all cells of the body. Low external temperature increases metabolism in the body, delays the return internal heat; high - on the contrary. At high air temperatures, the body transfers internal heat to the external environment during breathing through the lungs, as well as through heat radiation through the skin. In the second case, heat is emitted in the form of infrared rays. When the air temperature rises to the animal's body temperature, radiation from the surface of the skin stops. Therefore, into the room barnyard it is important to maintain a normal microclimate (Table 1), and temperature fluctuations should not exceed 3°. The maximum room temperature for most types of farm animals should not exceed 20 °C.
Air humidity is determined by hygrometers. Absolute humidity is characterized by the amount of water vapor (g) in 1 m 3 of air, maximum humidity is the maximum amount of water vapor that can be contained in 1 m 3 of air at a given temperature. Humidity can be expressed as a percentage - as the ratio of absolute humidity to maximum humidity. This is relative humidity and is determined using psychrometers.
Indoor air humidity is important. With high humidity and temperature and weak air movement in the room, heat transfer is greatly reduced, resulting in overheating of the body, and this can lead to heat stroke. Under such conditions, the animals’ appetite, productivity, resistance to diseases decrease, and lethargy and weakness appear. High air humidity at low temperatures has a negative effect: it causes the body to lose large quantity heat. To make up for these losses, the animal requires additional food.
At any temperature, animals feel better and produce better in dry air conditions. Heat transfer in dry air and high temperatures is carried out by the body through sweating and evaporation of moisture through the lungs during breathing. At low temperatures, dry air helps reduce heat transfer. Solar insolation plays an important role in the life of the body. Under the influence sun rays Metabolism in the body is enhanced, in particular, the supply of organs and tissues with oxygen is better, and the deposition of nutrients in them - proteins, calcium, phosphorus - is enhanced. Under the influence of sunlight, vitamin D is formed in the skin. Sunlight, neutralizing pathogenic microorganisms, creates for animals favorable conditions, increases the resistance of their body against infectious diseases. In case of insufficient sunlight the animal experiences light hunger, as a result of which a number of disorders occur in the body. Too much solar insolation also has a negative effect on the body, causing burns and, often, sunstroke.
The sun's rays intensify hair growth, enhance the function of the skin glands (sweat and sebaceous), while the stratum corneum thickens and the epidermis thickens, which is very important for strengthening the body's resistance.
During the winter stable period, regular walks for animals should be organized and their artificial ultraviolet irradiation should be practiced (with the necessary precautions taken).
Conclusion.
Failure to comply with indoor microclimate requirements leads to a decrease in milk yield by 10-20%, a decrease in weight gain by 20-30%, an increase in the waste of young animals to 5-40%, a decrease in egg production of chickens by 30-35%, the consumption of additional amounts of feed, and a reduction in service life equipment, machines and buildings themselves, reducing the resistance of animals to various diseases.
Bibliography.
1. Melnikov S.V. Mechanization and automation of livestock farms and complexes. - L.; Ear. Leningr. department, 1978.
2. V.G. Koba, N.V. Braginets, D.N. Musuridze, V.F. Nekrashevich. Mechanization and technology of livestock production; Tutorial for agricultural universities- M.; Kolos, 1999.
3. N.N. Belyanchikov, A.I. Smirnov. Mechanization of livestock farming. - M.: Kolos, 1983. - 360 p.
4. E.A Arzumanyan, A.P. Beguchev, V.I Georgevsky, V.K. Dyman, etc. Animal husbandry. - M., Kolos, 1976.-464p.
5. N.M. Altukhov, V.I. Afanasyev, B.A. Bashkirov et al. A short reference book for a veterinarian. - M.: Agropromizdat, 1990. - 574 p.
6. S. Kadik. Ventilation and ventilation are different. /Livestock production in Russia/ March 2004
When the microclimate of livestock premises for cattle does not meet the standards, the farmer himself suffers first of all. Lack of light, high humidity, heat and other, sometimes unobvious factors reduce the productivity of animals and their lifespan. In addition, they affect the durability of the equipment and the premises themselves. By organizing the keeping of animals according to all the rules, you may incur additional expenses at first, but they will more than pay off in the future.
On the importance of environmental indicators
Microclimate is all environmental indicators together. Air temperature, humidity, light, air composition, presence of bacteria.
The microclimate is influenced by a number of factors. These are the climate in the region, the time of year, the number of animals, ventilation systems and the size of the premises, their thermal conductivity, daily routine, the way the livestock is kept and even its age.
Changes in the microclimate invisible to the eye can seriously affect the health of animals and reduce their productivity by 20-40%. The increase in live weight decreases, and young animals die more often. Also when unfavorable conditions the number of diseases in the barn increases, which leads to a general loss of livestock. This is especially difficult for calves, highly productive cows and breeding stock. At the same time, if we talk about temperature, both very low readings and heat are harmful. Moreover, cattle endure the stuffiness especially hard.
In addition, a poor microclimate almost triples the service life of agricultural premises and requires more frequent and expensive repairs. It also affects the health of the company’s employees.
Temperature standards in premises for cattle in summer
Air temperature directly affects heat exchange processes in the body of animals. Its unfavorable values lead to a decrease in milk yield, changes in appetite, and disturbances in the functioning of internal organs.
Cows tolerate high temperatures in summer worse than cold. It is especially dangerous when there is high humidity and lack of ventilation. In the heat, cattle's metabolism slows down, the production of digestive enzymes and gastrointestinal motility decreases. As a result, appetite decreases, nutrients from feed are poorly absorbed and productivity decreases.
In addition, cows sweat, losing salts and vitamins. Their hemoglobin decreases and the overall composition of their blood changes.
The optimal temperature for a barn is from 8 to 22 degrees Celsius. Then the processes of “inhibition” begin in the cattle’s body.
If the thermometer in the animal room shows 30 degrees in the summer, this is unacceptable. Therefore, it is very important to cool the barn in hot weather.
Cooling systems for livestock buildings
The barns are cooled by ventilation. It also helps purify the air. Ventilation systems can be of various types:
- using mixers;
- supply and exhaust (or natural) ventilation;
- tunnel ventilation;
- cross ventilation.
Fans or mixers should have a radius of 70 cm and be located at a distance of 10-12 m from each other at an angle of 15 degrees. This way the air will actively circulate between them. However, in hot weather, these devices are ineffective, since the source of air for them is either the street or a barn.
Tunnel ventilation works well in narrow barns. Fans are installed at one end of the room so that they drive air at a speed of 7 m per second. Heated air is also drawn out.
Cross ventilation is different in that it is used in barns with large area. Fans are placed throughout the room, arranged lengthwise.
Where the air comes from, you can install cooling radiators to reduce the temperature. This is quite expensive, since fans are installed every two meters.
More about natural ventilation
Such a ventilation system can be pipe or pipeless. The first one is more effective. It includes openings for air flow in the walls and exhaust pipes with valves that extend beyond the roof ridge.
A pipeless system is ventilation through windows, openings in walls, and gates. Its disadvantage is that it is practically impossible to adjust and is highly dependent on weather conditions, but this is the most common system.
In summer, all air openings are opened. It’s good if the building is tall and wide enough - in hot weather there should be about 40 cubic meters of space per cow. Windows are made in the longitudinal walls for air flow. Their transoms open inward to allow air to flow parallel to the roof line. Windows must be equipped with protective screens. A light ridge on the roof of the barn is also necessary. In this case, the roof should have overhangs of up to 1 meter so that rain and direct rays of the sun do not fall on the cattle.
Air exchange rates in summer: 70 cubic meters per hour per hundredweight of adult animals, from 100 to 120 cubic meters for calves, for young animals - 250 cubic meters per hour.
Ventilation and temperature in the cold season
Cows tolerate cold well, so in those countries where there is no strong minus, cowsheds are often built, similar to a barn, with almost completely open walls. When it gets colder, the openings in the walls are covered with a special film. However, this method is not suitable for Russia. Especially for regions where there are frosts above 20 degrees.
In winter, the barn should be protected and well ventilated at the same time. Although cows love cool weather, the temperature should not fall below +4 degrees. Optimally, as we have already written, from +8 degrees. Theoretically, it could be colder, but this entails excessive consumption of feed, injury to animals from freezing manure, and damage to equipment.
Thermal insulation of enclosing structures plays an important role. In winter, it allows you to retain the heat generated by animals without interfering with the cooling of the premises in summer.
The air flow in winter should be in a volume of 17 cubic meters per hour for each centner of adult cows, from 20 cubic meters per hour for calves and 60 cubic meters for young animals. Air movement speed is no more than 0.5 meters per second. It is also necessary to take into account that air penetrates into the room through various cracks, so for the winter all supply openings are reduced by 30%. The size of the holes in the skate area should be 10 cubic meters. m.
Which humidity is better - low or high?
In fact, neither one nor the other. Humidity, just like temperature, greatly influences thermoregulation. In particular, on heat transfer. Moreover, humidity above 85% is harmful both at very high and low temperatures.
The optimal humidity level for keeping livestock is 50-70%. High humidity slows down metabolic processes, reduces the body's resistance to infections. So, if the barn is very humid, animals are much more likely to suffer from gastrointestinal, colds and skin diseases. Calves living in rooms with a humidity of 90-100% and a temperature of +10 to -2 degrees gain 15-20% less weight.
At the same time, too low humidity is also dangerous. If it is less than 30-40%, and the temperature in the barn is higher than normal, this not only causes severe thirst and dry mucous membranes in livestock, but also has a detrimental effect on the immune system.
The influence of the chemical composition of air on cattle health
In the process of life, cows secrete various substances, so the air where they are kept is not at all the same as outside. With a lack of fresh air masses and excess various gases animals begin to get sick, even to the point of death. That is why, speaking about the microclimate of barns, we cannot ignore this topic.
Ammonia and carbon monoxide (carbon monoxide) are also dangerous.
Ammonia is a product of the decomposition of feces and urine. In animals it causes diseases of the respiratory tract, mucous membranes, and anemia. Carbon monoxide happens where there is equipment that runs on fuel, gas-burners. It causes severe symptoms of poisoning and even coma. In the barn it should be no more than 2 mg per cubic meter. m.
Why are hydrogen sulfide and dust dangerous?
Hydrogen sulfide, even in small quantities, interferes with the “breathing” of cells, blocking the delivery of oxygen to them. As a result, animals begin to experience tachycardia, a sharp decrease in blood pressure, apathy, and weight loss. In rooms where adult animals are kept, the concentration of hydrogen sulfide can be no higher than 10 mg per cubic meter. m. For young animals it is two times less.
Hydrogen sulfide accumulates due to poor ventilation, sewage, untimely removal of manure and dirty bedding.
Dust is also harmful. It can be organic and mineral. Causes diseases of the respiratory system and mucous membranes. Dust irritates the eyes, causing conjunctivitis, and also disrupts protective function mucous membranes, which allows microbes to enter the body.
When it settles on the skin, it causes itching, irritation and, as a result, skin diseases. In addition, dust in the air reduces light levels in the barn.
To prevent dust, trees and shrubs are planted around the barn. Dry harvesting is never carried out in the presence of livestock. Also, the cows themselves are not cleaned in common areas.
Microbiological condition of the barn and lighting
The amount of light affects the health and productivity of any animal. This is important for the premises where they are kept, be it a barn, a poultry house or a pigsty. Its deficiency disrupts metabolic processes, the absorption of certain microelements, and promotes the deposition of excess fat.
Animals show the best results at illumination of 50-100 lux with a daylight duration of 12-18 hours. At the same time, organizing natural lighting of such intensity is not always possible or practical (due to the need for a large number of windows), so in practice artificial light is more often used.
Noise level and ion composition of air
The number of ions in the air is directly related to its purity. The more ions, the better. Thus, in mountainous areas there are up to 3 thousand ions in one cubic centimeter. At the same time, in ordinary places where the air is clean, there are about 1 thousand of them, in cities there are very few - 400-100 per cubic centimeter. In livestock buildings, the number of ions is two orders of magnitude lower than in the air outside.
However, ions have a positive effect on metabolism, the amount of oxygen in the blood, and hormonal levels. They also reduce air pollution from dust and germs. Therefore, artificial air ionization is recommended in barns.
In premises intended for cattle, the microclimate also includes the noise level. The acoustic background is created by all surrounding sounds combined. Due to noise, cows have disturbed sleep, anxiety and chronic stress.
For adult animals, noise intensity of no more than 70 decibels is acceptable, for calves – 65.
To improve the acoustic background, if possible, all noisy mechanisms are taken outside the barn, into a barn or other premises; Sound insulation is installed, tractors for manure removal and feed distribution are replaced with conveyors. Street noise is muffled by green spaces.
Control in animal premises
Measurement of microclimate parameters is carried out 3-4 times a month three times a day: early in the morning from 5.00 to 7.00, then from 12.00 to 14.00 and from 19.00 to 21.00. If necessary, the procedure is carried out for up to 12 days in a row.
Measurements are made with special instruments, selecting 2-3 zones in the barn: the place where the cows lie, where they stand and the area where the staff is located. The latter is important, since the microclimate also matters in occupational safety.
Measure at three points. In the middle of the room, then in two corners located diagonally. The distance from the end walls should be 3 m, from the longitudinal walls 1 m.
Measured at a level of 0.6 and 1.5 m from the floor in premises for adult livestock, for calves - at 0.3, then 0.7 and 1.5 m. Illumination, the amount of gases and microorganisms, temperature, humidity, intensity are taken into account noise.
In shaping the microclimate of premises, the terrain is of great importance, taking into account which the construction site is selected. The most suitable areas for locating farms are those located in elevated areas, with low groundwater levels, sheltered from cold northern winds and protected by forest plantings.
The location of the site relative to other farms, settlements, roads, industrial facilities. Failure to comply with sanitary gaps leads to contamination surrounding atmosphere, penetration of dust, microflora, harmful industrial gases, pathogens, industrial noise, etc.
Woody vegetation has a beneficial effect on the microclimate. It helps to reduce the air temperature in the territory and in livestock buildings by 3...6 and 7...13°C, respectively, in hot summer months. Under its influence, the air temperature rises by 2...4°C during the cold season. In the green zone and adjacent areas, the relative air humidity increases by 8.2% in summer, the speed of its movement decreases by 70.8...81.2% in summer and by 18.4...37.8% in winter. On sunny summer days, green spaces reduce the intensity of insolation by 40...50 times compared to open areas of the farm.
The presence of plantings around the farm reduces the amount of dust in the air by 51.1...72.8% in summer and by 8.7...23.1% in winter and thereby significantly affects the number of microorganisms in it. Thus, with green spaces, the number of microorganisms in the air decreases in winter by 22.7...52.6% and in summer by 5.8...16.3%. This is explained not only by their mechanical retention along with dust particles, but also by the active bactericidal effect of leaf phytoncides on the microbial cell.
Green spaces retain and absorb gases, reducing by 31.0...42.3% the spread of specific odors from farms, especially from open manure storage facilities. In addition, in the greening area, the air contains more negative ions, which have a beneficial effect on the body of animals and humans. Planting trees and shrubs around the perimeter of the farm and between buildings dramatically reduces the possibility of polluted air flowing from one room to another.
One of the conditions influencing the formation of the microclimate is the location of buildings. The territory should be planned taking into account the parts of the world and the prevailing winds in a particular area. The direction of the latter along the axis of the building promotes better ventilation of the space between them and prevents overcooling of the premises in winter. The direction of the building axis from north to south ensures good daylight premises and heat preservation in it. In the southern zones, on the contrary, by positioning the building from west to east, across the direction of the prevailing winds, good ventilation of the rooms is achieved and they are protected from overheating due to solar heat.
When developing the territory of farms and industrial complexes, the most important hygienic importance is the observance of sanitary gaps between individual buildings, as well as between interconnected rooms. Exhaust air emitted from one building is 5...7% sucked in forced ventilation adjacent room. To purify exhaust air, it is necessary to use filters and equipment exhaust ventilation chop visors directing the ejection upward. If such devices are available, sanitary gaps between buildings can be reduced to 30 m, and in their absence, they can be increased to 60 m or more.
The microclimate of livestock buildings is significantly affected by interior layout premises. For example, it is widespread to keep fattened young pigs in two- and three-tier cage batteries, in which an air environment of varying quality is formed. If the air temperature near the floor is conventional machines 17.3...19.6°C, on the first (lower) tier - 20.3...21.3°C, then on the top 22.3...22.5°C. Relative humidity air is also subject to changes - respectively 67.5...70.9; 62.5...67.5 and 59.1...66.9%. The temperature of the floor surface of the machines is 3.6 and 4.6 °C lower than on the lower and upper tiers.
The highest microbial air pollution (153...161 thousand/m3) was observed in the machines near the floor, while on the lower and upper tiers it was lower by 26.1...44.1%. The concentration of ammonia in the pens near the floor was 0.015 mg/l, on the lower and upper tiers it decreased by 20 and 33.3%; the carbon dioxide content is 0.17 and 0.14...0.13 mg/l, respectively. The speed of air movement in the machines was 12.5...15.8% higher than in the tiers of the cell battery. In the lower tier, illumination sharply decreases.
In pigsties for weaned piglets with lattice fences on pens, their contamination is 2-3 times greater than in pens where the lattice wall is only in one part of it - at the point of contact with adjacent pens. As a rule, in this part there is a defecation zone, which is much smaller in size than in machines with solid lattice walls. As a result, the area of contamination of machines is reduced, moisture evaporation and the release of harmful gases are reduced, and the air in the pigsty becomes drier and cleaner.
It is impossible to create a microclimate in livestock buildings without effective thermal protection of enclosing structures. Thermal insulation allows you to reduce heating costs, quickly regulate microclimate parameters and avoid the formation of condensation on the walls.
The thermal protective properties of buildings determine the thermoregulatory functions of animals.
Good thermal protection of the enclosing structures of livestock buildings in winter allows rational use of animal heat, and in summer it creates coolness, protecting animals from exposure high temperatures from outside.
When constructing livestock buildings, the choice of building materials is determined primarily by the purpose of the structure, local conditions and climatic characteristics of the area.
For example, in areas with stable temperatures of minus 25...30°C it is necessary to use Construction Materials with a coefficient of thermal resistance (Ro) in the range of 8.37...10.47 kJ/(m 2 HHH°C). However, now in most typical livestock buildings the parameters of thermal resistance to heat transfer of walls are set at the level of 3.35...4.61, and for coatings - at the level of 5.44...5.86 kJ/(m 2 HHH°C), while in the construction practice of foreign countries (USA, Sweden, Norway, Poland, Germany, England) thermal resistance it is designed twice as much (for walls 5.86...10.47, for coatings 8.37...10.47 kJ/(m 2 HHH°C), although the average winter design temperature in these countries is much higher. Improving the heat-protective properties of enclosing structures requires additional costs, so it must be economically justified.
Particular attention should be paid to bedding material. Heat loss through the floor is 30...40% of all heat loss in the room, therefore it is necessary that the heat absorption rate does not exceed 41.86...50.24 kJ/(m2HHH°C); if it is above the upper limit, then a lot of the physiological heat of the animals is spent on warming the floor, and this can lead to hypothermia of the body. The use of bedding material not only reduces heat loss, but is also used to absorb moisture.
The microclimate in livestock buildings largely depends on the normal functioning of the sewage system, as well as on how regularly the manure is removed. Without properly equipped and trouble-free sewage systems in buildings and on farms, it is impossible to create an optimal microclimate.
The problem of creating a microclimate in industrial livestock farming cannot be solved without effective systems ventilation.
With the concentrated type of feeding and high animal productivity, increased demands are placed on the air environment. Good feeding helps to increase metabolism; therefore, for the oxidation and absorption of feed, it is necessary that the animal’s body contains clean air sufficient oxygen was supplied. The more intense the metabolism, the more animals consume oxygen from the air and the more carbon dioxide they release when breathing, at the same time significant amount heat and water vapor. Therefore, when keeping animals for a long time in indoors the role of air exchange increases. Air exchange not only allows you to create optimal temperatures in livestock buildings, but also humidity conditions and maintain the gas composition of the air in accordance with zoohygienic standards, but also helps remove dust and microorganisms. That is why ventilation is one of the most effective means, with the help of which we can change the influence of the air environment on the physiological state and productivity of animals in the direction we need.
One of the main requirements for ventilation systems is to ensure the most perfect air exchange from a physiological and economic point of view. Insufficient air exchange creates an unsatisfactory microclimate, which ultimately leads to increased feed costs per unit of production, decreased animal productivity, premature culling and large economic losses.