What are the environmental conditions for healthy brooding? How to control it?

The environmental conditions for healthy breeding of chicks mainly include temperature, humidity, light, air quality, density and so on. Controlling these conditions is very important for healthy farming.

1. Temperature control

Chicken's thermoregulation function is not perfect, and it is afraid of both cold and heat. ① Excessive ambient temperature affects the heat and water dissipation of chicks, leading to the disorder of heat balance, loss of appetite, growth retardation and increased mortality; (2) When the ambient temperature is too low, chicks will get together and move inflexibly, which will affect food intake and drinking; ③ When the ambient temperature is unstable, chicks are prone to catch cold and dysentery, and the mortality rate increases. See Table 5- 1 for the suitable temperature of chicks of different days.

Table 5- 1 Suitable temperature for chickens of different days.

It needs to be clear that the brooding temperature includes brooding room temperature and brooder temperature. For a plane brooder, the temperature of the brooder refers to the temperature of the edge of the brooder (such as a hot umbrella) 5 cm away from the ground or the net surface, and the temperature of the brooder room refers to the temperature measured on the wall 65,438+0 meters away from the brooder or indoor heat source. For brooding in cages, the temperature of brooder refers to the temperature of 5 cm above the bottom net of heat source area in cages, and the temperature of brooding room refers to the temperature of 1 m above the ground outside cages. There should be some difference between the two temperatures. Generally, the temperature of the brooding room is lower than that of the brooder, so that the temperature of the whole brooding environment can be divided into high, medium and low, which can not only promote the air flow, but also enable each chick to find the required temperature.

Besides the normal suitable temperature in Table 5- 1, the brooding temperature should be adjusted according to the chicken breed, constitution and external climate. For example, the feather growth rate of brown-shell chicken is slower than that of white-shell chicken, and the temperature in the early stage of brooding can be higher; The external temperature is higher when it is low and lower when it is high; It is lower during the day and higher at night. Generally, the temperature of brooding at night is 65438 0 ~ 2℃ higher than that during the day. Healthy chicks are lower and weak chicks are higher; The brooding of large groups is low, while that of small groups is high. With the increase of chicks' age, the temperature of brooding will drop continuously until they are out of body temperature. Generally, the cooling transition period is 4 ~ 6 weeks old, and the incubator drops by about 3℃ every week. Chickens should have an adaptation process to get rid of the temperature. At first, it will be warm during the day, at night, when the weather is good and on cloudy days. After 5 ~ 7 days, the chickens adapt to the natural temperature, and finally achieve complete temperature loss. The temperature of chickens depends on the season, and the temperature is about 30 days in the morning and evening in summer and 40 days in winter. If the chickens are found to be in poor health and underweight during the feeding process, it can extend the dewetting time and help the chicks recover their health.

In production, breeders should take the temperature of chickens as the main basis for temperature adjustment and take thermometers as a reference. Chickens are lively and active, full of energy, with brisk calls, good appetite, moderate water consumption, smooth and tidy feathers, normal feces, evenly distributed around the brooding cage or the bottom net of the brooding cage at rest after satiety, straight head and neck sleep, no abnormal state or uneasy calls, and quiet in the henhouse, indicating that the temperature is suitable. If the chicks are found to be slow-moving, fluffy, shivering, crowded under the heat source, huddled up, afraid to go out to eat, making sharp and short calls from time to time, and in poor mental condition, it means that the temperature of brooding is too low. If chicks are found to be far away from the heat source, crawling on the ground, spreading their wings, stretching their necks, panting with their mouths open, drinking too much water and losing their appetite, it means that the temperature is too high. Mastering this "biological thermometer" is very important for brooding.

2. Moisture regulation

Laying hens are not as strict in humidity requirements as temperature during brooding, but under special conditions, or when combined with other environmental factors, improper humidity will do great harm to chicks. In general, the relative humidity of the henhouse is 60% ~ 65%, and 40% ~ 72% is the suitable humidity for chickens. More than 85%, the air is too humid, which affects heat dissipation; Below 35%, the air is too dry, which will affect the defense ability of mucosa and skin, easily cause respiratory diseases, and also make chicken feathers grow poorly, leading to dehydration of chicks. Proper humidity should be mastered flexibly. Chickens of different ages, regions and seasons need different suitable humidity. The general feature is that the front is high and the back is low. 60% ~ 70% after 10 day, and 50% ~ 60% after10 day.

Besides hygrometer, the relative humidity of the brooding room can also be judged by the breeder's own feeling and the performance of chicks. When the relative humidity is appropriate, people will feel hot and humid when they enter the brooding room, but their nose and mouth will not feel dry, their feet will be moist and delicate, and their mental state will be good. When the chicken flies, there is basically no dust in the room. If you feel dry nose and mouth when you enter the brooding room, the chicks will keep drinking water around the water fountain, indicating that the humidity in the brooding room is too low. If the utensils and walls in the brooding house are wet or have dew, it means that the humidity is too high. In the production practice of laying hens, in the early stage of brooding, the relative humidity in the shed may be insufficient, and in other cases the relative humidity is high. There are several points to control the humidity of the brooding room: the chicken farm should be built in a high and dry place, and the inner surface of the house should be about 30 cm higher than the outer surface of the house, and it should be treated with moisture. The newly-built henhouse should be fully dried before use: reduce the water leakage of the water supply system, control the amount of sprinkling water, often clean the feces or replace the wet padding, or add absorbent calcium superphosphate (0. 1 kg per square meter) to the ground and padding, but avoid using quicklime. In dry season, ventilation is used to change indoor humidity, but attention should be paid to heat preservation. To improve humidity, spray disinfection is mainly used for humidification, steam generated by boiling water, sprinkling water on the ground and hanging wet curtains indoors.

3. Lighting control

Lighting control is the control of the brightness of henhouse, which is related to the luminous intensity and luminous flux of light source. Illuminance is the ratio of luminous flux to illumination area, also known as illuminance. The unit of illuminance is expressed in lux (lx), which refers to the illuminance generated when the luminous flux of 1 lumen (1m) is uniformly irradiated on the area of 1m2. The light intensity in the henhouse can be roughly calculated by bulb wattage, lamp height and lamp distance. Generally, the illuminance per square meter 1 watt bulb or 27 watt bulb can reach 10.76 le in an area of 0.37m 2. Generally, the bulb height is 2 ~ 2.4m, and the bulb spacing is 1.5 times the bulb height. Use more 25W or 40W bulbs. Illumination includes illumination time and intensity, and natural light sources and artificial light sources can be used in actual production. Before the chicks are 3 days old, they should be exposed to strong light for a long time, generally 20 ~ 23 hours and 20 lux, so that the chicks can drink water and start eating as soon as possible. 4 ~ 7 days old, light for 20 hours every day, and then reduce the light time 1 hour every week. The light intensity is about 50 lux before the age of 3 days, 20 lux at the age of 4 ~ 15 days, and 10 ~ 15 lux thereafter.

Natural lighting should take into account the weather conditions, trees outside the window, the size and location of the window, indoor equipment, different locations in the room, the presence or absence of glass and the cleanliness of the glass. When the window glass is dirty, the illuminance in the room will be reduced by about half, and the light transmission effect of plastic film is similar to that of dirty glass. Setting skylight or transparent belt on the roof will obviously improve the lighting effect in the middle of the henhouse. Painting the south window glass can reduce the light intensity in the south of the house. When using artificial lighting, the bulbs should be staggered evenly, especially in a flat and maintained henhouse. In the cage chicken house, there are obvious differences in the light intensity between the upper and lower floors, especially in the stacked chicken cage, and the light intensity difference between each floor will be even greater. It is necessary to install light bulbs at multiple levels to ensure the proper light intensity of the lower cage. The artificial light source can be incandescent lamp or fluorescent lamp. Fluorescent lamps with the same power produce illumination 3 ~ 4 times that of incandescent lamps. However, the investment of fluorescent lamps is large, and the light efficiency decreases at low temperature. Using incandescent lamp shade can improve illumination by 50% by reflecting light. If the light bulb is too dirty, it will reduce the illumination by 30% ~ 50%, so it is necessary to clean the light bulb once a week.

4. Air quality control

Due to the respiration and excretion of chickens and the decomposition of organic matter such as feces and feed, the proportion of the original components in the air in the henhouse will change, thus increasing the contents of harmful gases such as ammonia, hydrogen sulfide, methane, hydroxymercaptan and stench, as well as the contents of dust, microorganisms and water vapor. If the concentration of these gases and substances is too high, chicks are prone to respiratory diseases and eye diseases, and are prone to airborne infectious diseases, and the mortality rate will also increase. Air quality can be judged by measurement and the feeling of the breeder. In most cases, it depends on the feeling of the breeder to judge whether the content of harmful gases exceeds the standard. If the breeder feels smelly when entering the henhouse, and it will irritate his eyes for a long time, it indicates that the ammonia concentration and carbon dioxide content exceed the standard. At this time, the content of harmful gases in the air should be changed by ventilation while ensuring the temperature. The experience of production practice proves that in order to maintain good air quality in the henhouse, the number of air changes and airflow speed should reach: 0.7 ~ 1 m3/h kg body weight in winter, 0.2 ~ 0.3m3/s; In spring and autumn,1.5 ~ 2.5m3/hr kg body weight, 0.3 ~ 0.4m3/s; In summer, it is 5 m 3/ h kg body weight and 0.6 ~ 0.8 m 3/s. It is best to use good ventilation equipment for mechanical ventilation and combine it with natural ventilation. As long as people enter the henhouse without obvious smell, irritation and astringency, and feel chest tightness, breath holding and suffocation, they can think that breathing is appropriate.

The best time for ventilation is around noon on a sunny day. Ventilation should be carried out slowly, doors and windows should be opened from small to large, and finally they will be semi-open. Don't suddenly open the doors and windows, let the cold wind blow directly, and make the room temperature suddenly drop. Don't blow the chicken directly through through flow and intermittent wind, so as not to catch cold. Ventilation can also be achieved by installing gauze or curtains, opening blinds or adding buffer rooms, so as to achieve the purpose of ventilation under heat preservation conditions. In production, we should also pay attention to cleaning up the feces in time, keeping the house dry, changing the padding regularly, reducing the dust in the house, and adding compound enzyme preparations to the balanced diet.

5. Feeding density control

Feeding density refers to the number of chickens per square meter. Feeding density has a great influence on the growth and development of chicks. The density is too high during the brooding period, the range of the flocks is small, the flocks are crowded, the strong eat more, and the weak eat less, which easily leads to uneven individual size, which can induce many diseases and pecking habits and increase the mortality rate. The density is too small, which leads to the waste of henhouses and equipment, and is not conducive to heat preservation. Feeding density can be determined according to the specific situation. When the outside temperature is high, the density can be reduced accordingly. When the outside temperature is low, the feeding density can be increased accordingly. Compared with winter and spring, the density in summer and autumn should be reduced by 3 ~ 5 per square meter. The feeding density of heavy chickens should be lower than that of light chickens. Weak chickens are worse than strong chickens and can't stand crowds. In addition to feeding separately in groups, the feeding density should be reduced. When the ventilation is good, the feeding density can be increased, and when the ventilation is poor, the feeding density should be reduced. We should be flexible in production. Generally speaking, when the ground bedding is raised at 1 week, it is 30 ~ 40 animals /m2, and the weekly feeding density will decrease accordingly, reaching 10 animals /m2 at 7 ~ 8 weeks. Flat or online flat culture can increase the flat culture density by about 20%, and the three-dimensional cage culture is 40-50 heads /m2 in 1 ~ 4 weeks, and 20-30 heads /m2 in 5-1~ 0 weeks.

6. Other conditions control

Noise and the change of breeders will also affect the production of chicks, because chicks are timid and easily frightened and are particularly sensitive to changes in external conditions. They are often surprised by the noise or strangers entering the henhouse, which is manifested by screaming, jumping around and crowding together. Therefore, the environment should be kept quiet and the breeders should be fixed during brooding.