Common stress problems in the process of raising chickens

Common stress problems in the process of raising chickens

1. temperature: when the temperature is too high, too low or sudden large rise and fall. When the temperature is not balanced, if you suddenly encounter cold stimulation. It will damage the function of the respiratory mucosal barrier, stop the activity of ciliated epithelium, reduce the secretion of lysozyme, intensify the decomposition of tissue protein, increase the amount of macromolecular colloidal protein in the blood, and weaken the activity in the net, resulting in the weakening of the body's resistance. When the high temperature environment, the body to regulate metabolism for survival and reduce heat production, such as reducing feed intake, resulting in insufficient nutritional intake, so that economic production indicators are affected, laying hens and breeders egg production decreased, eggshell thinning brittle, fertilization rate decreased, chicken weight decreased, mortality increased. [Chickens have no sweat glands, and their epidermis has poor evaporative heat dissipation ability. They only rely on breathing to evaporate heat dissipation. When the external temperature reaches above 37-38 ℃ and the respiratory frequency exceeds 110 times/minute, the body will cause alkalosis due to cardiovascular failure and large exhaled carbon dioxide. Clinical respiratory diseases such as shortness of breath and wheezing are found, and then failure and death.

2. oxygen supply and harmful gases: The chicken house lacks scientific and reasonable ventilation and oxygen supply equipment in the construction, and the ventilation cannot be automatically adjusted according to changes in the amount of harmful gases. It cannot meet the oxygen demand of chickens. When the ventilation is poor, the body's oxygen supply is insufficient, harmful gases exceed the standard, causing the metabolic respiratory frequency of the chicken to accelerate, and the respiratory mucosa is stimulated by ammonia, hydrogen sulfide, carbon monoxide, etc., causing the cilia to fall off, causing the local defense function to decrease, leading to infectious diseases. occur.

3. humidity: chickens in chicken houses with humidity not lower than 50-60% and lasting less than 50% for seven days will suffer from nostril blockage due to continuous drying of nasal mucosa due to environmental dryness and large amount of dust, nostril discomfort sneezing and respiratory diseases.

4. density: when the breeder unilaterally pursues the scale benefit, in the relatively simple chicken coop, the feeding amount per square meter has exceeded the requirements of the standard environmental control chicken coop, or does not pay attention to the feeding density, and is divided into groups too late, it will lead to insufficient oxygen supply, insufficient water and materials, insufficient moving area, insufficient heat dissipation, increased pathogen transmission speed, and affect the growth of chickens.

In order to reduce the feeding cost, some small-scale chicken factories adopt early brooding in heat preservation houses and transfer to growth houses at about 20 days of age. Many chickens develop during this period of time, especially respiratory diseases cause changes in the internal environment of the body during the transfer and merge, resulting in a decrease in the body's resistance and an increase in the susceptibility of pathogenic bacteria.

The 6. group is too large: when a chicken coop is not blocked and the chickens are raised in a large environment, some local stresses will become the overall environmental stress, especially the non-environmental control chicken coop, which will increase the tendency density of the chickens in the environment due to good local ventilation, turning the local environment into adversity and causing respiratory tract.

7. raise chickens of different ages in the factory: chickens of different ages have different susceptibility to pathogens, and chicken houses of different feeding periods have different degrees of bacterial contamination. When chickens of different ages are raised on the spot, respiratory tract is more likely to occur, and it is difficult to cure after occurrence.

8. vaccination: there are several reasons for the respiratory tract caused by vaccination. 1. The virulence of the vaccine is too strong and the stimulation of the respiratory mucosa is too large. 2. The vaccine is contaminated by embryogenic mycoplasma, which pollutes the chicken body when used. 3. Before the chicken group is immunized, there is a potential respiratory disease, and the vaccine immunization causes respiratory disease. 4, drinking water immune stop time is too long, causing stimulation to the body. 5. When aerosol immunization, aerosol particles are too small to enter the deep part of the respiratory tract, resulting in tracheal spasm and respiratory disease.

9. feeding: chickens need to adjust their feed at least 2-3 times during the whole feeding process. during the feeding process, there will be changes in the shape, nutritional content and palatability of the feed, making the body reflect on it (mainly the stress of the chicken's internal environment and the changes in nerve and humoral regulation caused by it, which will reduce the body's resistance and lead to the onset of disease.)

The above-mentioned stresses are more susceptible to single or non-cruel chickens, but in actual production, they are usually cruel stresses and more than two stresses. Therefore, chickens with too fast growth rate and poor tolerance will show up in the form of diseases, and the incubation period is short, the speed of transmission is fast, and the course of disease is long and difficult to cure.