1. Environmental characteristics of plastic greenhouses
Common duck houses raise ducks in winter, and the main source of house temperature is the biological heat emitted by the ducks. The outside temperature is low, the duck house has poor thermal insulation performance, and the duck body emits more heat. This will not only increase the duck's feed intake, but also cause the duck's death in severe cases. In addition, the investment in the ordinary duck house is relatively large, which increases the cost of breeding, and the risk is also greater. Raising ducks in plastic sheds can well retain the biological heat emitted by the ducks. It can also use the light energy of the sun to convert people into heat to raise the room temperature. It has certain advantages in winter. At the same time, it saves investment and can be used for injection. The ultraviolet sterilization in the sunlight can enhance the immunity and disease resistance of ducks, promote the bone development of ducks, stimulate appetite, promote digestion, and can also promote the development of the body temperature regulation function of ducklings. Its breeding superiority goes without saying Metaphor. However, due to the poor air permeability of plastic sheds, the temperature and harmful gas content in the house are often too high during breeding. Therefore, when plastic sheds are used, they must be designed reasonably, and necessary ventilation and auxiliary adjustment facilities should be considered to maintain the environment in the shed. The best microclimate for duck growth.
2. Design and technical requirements of plastic greenhouses
Plastic greenhouses should be built in places with high dryness and sufficient sunlight. Tall buildings and woods should be avoided as much as possible. There should be tap water or clean water sources nearby, as well as power lines, and the transportation must be convenient and without interference. Don’t let the wind go, the scaffolding is best for east-west orientation. The structural requirements of the plastic greenhouse are as follows.
3. The slope of the shed roof
When the angle between the sunlight and the plastic film is 90°, the light transmittance is the highest. According to my country's winter solstice at noon, the incident angle of sunlight is 21°33'-26°33', the angle between the plastic film and the ground should be 63°27'-68°27'. Such a slope is completely covered by plastic film on the roof, and the duck-raising shed is completely achievable.
4 The height of the shed
The height of the plastic greenhouse in the design should generally reach about 2.5m, which is not only conducive to the operation of the breeding staff, but also conducive to ventilation in the house.
5. The orientation of the shed
When designing a greenhouse, the main axis is generally east-west axis, sitting north to south, which is conducive to direct sunlight into the house and makes full use of solar energy.
6. Plastic film material
It is more appropriate to use polyvinyl chloride film in the plastic shed for ducks, and the thickness of the plastic film should be 0.08-0.12mm.
7. Setting of ventilation openings
The exhaust outlet of the shed should be located on the leeward side of the shed, and a windproof cap should be installed at the exhaust outlet 50cm above the roof of the room. This not only prevents cold air from filling people, but also facilitates smooth ventilation. The air inlets of the shed should be located at the gables on both sides. The size of the exhaust vent should be determined according to the number of ducks raised. For example, a greenhouse for raising meat ducks on the ground (such as a greenhouse with a length of 20m, a width of 5m, and a greenhouse with 1,000 meat ducks in the later stage) can be set up with an area of 25cm×25cm leeward There are 5 exhaust ports on the surface and 5 exhaust ports on the roof.
8. Technical performance and environmental regulation of plastic greenhouses
The plastic shed is a close-closed specific environment, and each factor of its environmental conditions has its own special law of change. The success of the breeding of meat ducks in the shed depends on the degree of influence of various factors in the shed environment on the meat ducks, on the other hand, it depends on the adaptability of the meat ducks and the ability to manually adjust the environment of the shed. Understanding the requirements and adaptability of meat ducks to the environmental conditions of the shed, and being familiar with and mastering the general changing laws and artificial control methods of environmental factors before and after raising meat ducks in plastic sheds are the basis for doing a good job of raising ducks in plastic sheds.
9. Thermal insulation and temperature control of greenhouse
On the one hand, the heat of the plastic shed comes from the sun’s radiation, and on the other hand, it comes from the biological heat emitted by the ducks. No heat preservation measures are taken, and the indoor temperature difference between day and night is 10-15 ℃. Such a large difference in temperature between day and night is harmful to the feeding of meat ducks. Therefore, it is necessary to reasonably set up heat preservation devices to increase the indoor temperature and reduce the temperature difference between day and night. In a sense, the quality of temperature management will directly affect the success or failure of meat duck breeding. Therefore, when a reasonable plastic greenhouse structure is selected correctly, certain heat preservation measures must be taken through the adjustment of the size of the vents and the cover and roll. Insulation curtains are used to adjust the room temperature, and the greenhouses must be equipped with "quilts" and straw curtains. At night, the paper "quilt" should be covered on the surface of the plastic film; when the outdoor temperature is very low, a straw curtain should be added to the paper "quilt", and the back ventilation window can be closed if necessary. When the outdoor temperature rises during the day, the straw curtain and paper should be rolled up and fixed on the top of the greenhouse. The ventilation windows can be opened for ventilation and cooling from 12:00 noon to 14:00 pm.
10. Humidity characteristics and dehumidification of plastic greenhouses
High air humidity is the main feature of duck breeding in plastic greenhouses. The greenhouse has a small space and poor air permeability. When not paying attention to ventilation, the airflow will be relatively stable. During the day when the temperature is high, the amount of evaporation is large, and the greenhouse environment is relatively closed, and it is not easy to convection with the outside air, so the indoor humidity often appears to be too high. At night, on cloudy days, especially when the temperature is low, the relative humidity of the air is even saturated. Such high humidity conditions are harmful to the feeding of meat ducks. The humidity in the greenhouse mainly comes from the evaporation of feces and breath of meat ducks, especially during the daytime when eating and exercising, its metabolic rate is high, the respiratory rate is fast, and the feces are more concentrated in the daytime excretion, so the duck shed during the day The humidity will be higher than at night. To reduce the humidity in the shed, in addition to paying attention to the topography when choosing a shed site, it is also necessary to pay attention to timely ventilation. The best choice for ventilation is during the day, because the ducks in the room have a high metabolic rate during the day, and they defecate more and are humid. At the same time, the temperature is high during the day and the ducks have a large heat dissipation capacity. At this time, ventilation will not cause the shed temperature to drop suddenly. In addition, the feces discharged by the ducks should be cleared in time during the feeding, and the bedding should be replaced in time if the greenhouse is raised with bedding. As long as it is properly adjusted, the humidity can be controlled well.
11. The air condition of the plastic greenhouse and the removal of harmful gases
Plastic greenhouses are often airtight. If ventilation is not strengthened, the concentration of H2S, NH3, CO2 and other gases in the shed will be much greater than that in the air, which will affect the normal growth of meat ducks. Effectively controlling the time and frequency of ventilation is an important task in the management of duck breeding in plastic greenhouses. Under the premise of not affecting the indoor thermal insulation, the design should be designed according to the maximum ventilation. A reasonable amount of ventilation can be selected according to the needs when using it. The size of the ventilation is mainly determined by the adaptability of the meat duck. It can be more appropriate during the day, and the adult duck is more than the young duck.
12. Light transmittance and light management of plastic greenhouses
The superiority of raising meat ducks in plastic greenhouses is especially obvious in winter when the climate is good and the sun is shining. However, at this time, the intensity of the sun will be too high due to direct sunlight into the shed, especially at sunny noon, which makes the radiation intensity stronger. Although this is helpful to increase the room temperature, it will also cause duck pecking habit due to excessively high illumination. Therefore, when the illuminance is high, the ducks in the greenhouse should be shaded. When using shading measures, in order to allow sunlight to penetrate into the room in winter to increase the room temperature, a straw curtain can be placed tens of centimeters away from the plastic film in the shed to block the light; shading should not be done outside in winter to avoid affecting the temperature in the shed, but in summer When raising ducks in a large shed, in order to prevent the temperature in the shed from being too high, it is necessary to perform shading treatment outdoors. At the same time, due to the short sunshine time in winter, especially on cloudy days, the only natural light can not meet the feeding time of meat ducks and the needs of night heating, and it is even inconvenient for the keepers to observe. Therefore, it is necessary to supplement the light time in the greenhouse.
