1. Newcastle disease
[Diagnostic methods] It is common in production, mostly occurring in chickens that have not been immunized for a long time or have poor immune effect or failed immunization. Feeding intake decreases (10-20%) and laying rate decreases (20-30%). The quality of eggs decreased, the eggshell became white and thin, the number of deformed eggs increased, the stool was green and sparse, and some had neurological symptoms. Pathological examination showed that the gastrointestinal tract had characteristic lesions of the virus.
[Prevention and control measures] Comprehensive prevention and control measures can be implemented for diseased chicken flocks. For example, emergency immunization should be strengthened, disinfection management should be strengthened, and anti-viral drugs such as ricetin, Duke No. 1, ketoterol and special killers, ciprofloxacin, anthronofloxacin, doxycycline and other antimicrobial agents should be used, supplementary nutrition (increasing the dosage of Jinweidu) should be taken to improve the body's disease resistance.
2. Avian influenza
[Diagnostic methods] Sometimes it shows endemic epidemic. The feed intake and egg-laying rate of diseased chickens decrease (30-60%), depression, purple crown, edema of individual crown, eyelid and beard, purple-black bleeding spots on leg scales, respiratory symptoms of different degrees, tracheal rings with a large amount of mucus, pulling green feces, glandular-gastric papilla bleeding or mucus, myogastric-cornea peeling easily, intestinal tract showing. Flake or strip hemorrhage, fallopian tube edema, pus, follicular deformation, bleeding, easy to rupture. Renal enlargement and hemorrhage. Liver enlargement, often accompanied by lipid change or rupture and bleeding.
[Prevention and control measures] Comprehensive prevention and control of diseased chicken flocks should be adopted, feeding management should be strengthened, isolation and disinfection should be done well, body resistance should be improved, stress should be reduced and other outbreaks prevented. Drug treatment is necessary to reduce production losses. Banlangen Granule and antiviral drugs (ricknin, ketoterol or viral or virazole) can be used as drinking water or mixtures in large groups. It can also use amantadine VC, doxycycline and other drugs to reduce death and prevent secondary diseases. In the later stage of the disease, golden vitamin or golden egg powder can be used to promote the recovery of laying eggs.
3. Infectious bronchitis in chickens
[Diagnostic methods] Respiratory symptoms of adult chickens were obvious, but the egg laying rate decreased significantly, and the severity could be reduced by half. Abnormal eggs, thin-shelled eggs, faded eggs, thin protein, yolk and protein separation. Generally, laying eggs gradually recovered after 10 days. Variant infectious bronchitis in laying hens is caused by coronavirus, which occurs in laying hens and outbreaks more than 200 days old. The disease is closely related to stress, and all kinds of strong stress can induce the disease. In the early stage of the disease, the respiratory symptoms were mainly "grunting". In the absence of mixed infection, there was no cough or nose flick. The respiratory symptoms lasted for about 5-7 days, and the intake decreased by 5-20%. Faeces soften or pull water-like faeces.
(1) After the onset of new-born chickens, egg production rose slowly or stagnated or declined. After rehabilitation, it reached the original level.
(2) Egg production fluctuated 1-2 days before the onset of peak laying period, and declined rapidly after 2-3 days, generally 20-25%. Rehabilitation also reached the original level.
(3) After the onset of old age, the rate of laying eggs declined rapidly and rose slowly. At the same time, the quality of eggs decreased, the surface of eggshell was rough, the eggshell became thin, the color became white, the weight of eggs was small, the number of deformed eggs was large, and the abnormal eggs accounted for about 510%.