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Causes and preventive measures of broiler lung injury

Broiler lung injury is a serious respiratory disease, usually caused by the interaction of multiple pathogenic infections, environmental stress and many other factors. The high mortality rate brings huge economic losses to the poultry farming industry. Therefore, understanding the cause of broiler lung injury and taking effective measures to prevent it is the top priority of the current broiler farming industry.
1. Causes of broiler lung injury The
lung is a gas exchange organ. After the bronchus enters the lungs, it does not branch step by step to form a bronchial tree as in mammals, but forms interconnected tubes, and finally separates countless tiny pulmonary capillaries (also known as respiratory capillaries) from the tube wall, which are connected with the pulmonary blood vessels. The place where the blood directly exchanges gases.
Calculated per gram of body weight, the total respiratory area of the pulmonary capillary is dozens of times larger than that of mammals, which is compatible with the strong metabolic needs in the body. Chicken lungs can also perform double respiration, that is, gas exchange can be performed when inhaling and exhaling, thereby greatly increasing the ventilation volume of the lungs and improving the efficiency of gas exchange in the lungs. The air sac is a unique organ of poultry. It is a membranous sac formed after the branch of the bronchus leaves the lung, and most of it communicates with the lumen of many bones.
The lungs have an important impact on the physiological activities of chickens and are also the most vulnerable organs. Common lung injuries are generally caused by the following reasons.
1. Environmental factors
1.1 Temperature
1) At low temperature, cold air stimulates the respiratory mucosa and lung tissue, causing local vasoconstriction and circulatory disturbance, resulting in local nutritional deficiency, weakening or stopping of ciliated epithelial activity, increased tissue protein decomposition, and large Molecular colloid protein increases accordingly, and the activity of reticuloendothelial system weakens. The barrier function is damaged, the body's ability to resist infection is reduced, the respiratory mucosa is easily invaded by pathogenic microorganisms and spread to the lungs to cause lung infection, or the formation of new alveoli slows down, and abnormal gas exchange (oxygen, carbon dioxide) causes pulmonary hypertension , causing lung damage.
2) When the temperature is high, the first reason is that the chicken will breathe faster to dissipate heat, and the number of breaths will increase, which will lead to blood vessel congestion in the respiratory tract mucosa. Over time, due to the expansion of blood vessels, exudative inflammation will easily occur, and the cilia will easily fall off, exposing the mucous membrane, causing damage, and easily Infection with pathogenic microorganisms promotes the formation of pneumonia. Pulmonary congestion-congestion edema occurs. The second is that the heart rate increases at high temperature, shallow breathing leads to insufficient oxygen in the blood, the compensatory acceleration of the heart rate, and heart failure after the tachycardia can lead to venous blood return obstruction, pulmonary congestion, edema, and hypoxia in the body.
1.2 Humidity
1) Humidity is too high: if the humidity is greater than 70%, it will affect the body heat dissipation of the big chickens, and speed up breathing for heat dissipation to promote breathing and heat dissipation. High humidity increases the intrapulmonary pressure and causes congestion of the respiratory organs. Over a long period of time, pulmonary congestion-congestion-edema will occur, and lung consolidation will cause pneumonia.
2) Humidity is too low: the humidity is less than 30%, the air is dry, and there is a lot of dust (fine feathers, dust, powder, etc.). After inhalation, it enters the respiratory system with the air. Attached, too much will cause obstruction and poor breathing. If the number of microorganisms attached is large, it is also easy to cause respiratory infection or lung infection.
1.3 Negative pressure
The negative pressure of standardized chicken houses for broilers is required to be within -0.08 Mpa, and if the negative pressure exceeds -0.08 Mpa, it will cause a certain degree of damage to the lungs. When the negative pressure exceeds the standard, the back wind speed in the chicken house exceeds the normal standard, the amount of oxygen discharged from the chicken house increases, and the amount of oxygen entering the chicken house from the air inlet is not enough to replenish the oxygen to the normal value required by the chickens, and hypoxia causes pulmonary vasoconstriction , Pulmonary capillary venous pressure increases; on the other hand, hypoxia stimulates a large release of catecholamines, causing systemic circulation vasoconstriction, increased peripheral total resistance, increased left

Thursday, December 1st, 2022

I notice there are no preventative measures listed.
I assume a balanced temperature of 70F and humidity of 50% in coop.
Not easy to achieve in a domestic situation.

Cork Wyandotte
Sunday, December 4th, 2022

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