How to prevent and treat the main epidemic diseases in free-range chicken farming
Free-range chickens have strong disease resistance; some diseases that easily occur in improved-breed chickens rarely occur in free-range chickens. The main diseases affecting the health of free-range chickens include 3 viral diseases, 3 bacterial diseases and 3 parasitic diseases. Targeting the diseases to which free-range chickens are susceptible and taking into account local epidemic conditions, carrying out corresponding prevention and control work can effectively increase the survival rate of free-range chickens.
I. Prevention and treatment of 3 viral diseases
1. Newcastle disease: caused by Newcastle disease virus, generally manifested as difficulty breathing, diarrhea, green feces, depression and neurological symptoms, swelling of the head and face, cessation of egg laying, etc. The mortality rate of sensitive flocks is often as high as 90%-100%. Preventive measures: at 7-10 days of age, chicks are given the first immunization with Newcastle disease strain IV vaccine by drinking water or intranasal drops, the second immunization at 18 days of age, and intramuscular injection of Newcastle disease strain I vaccine at over 60 days of age;
2. Infectious bursal disease: caused by infectious bursal disease virus, with symptoms of sick chickens passing white or light green watery feces, listlessness, drooping head, closed eyelids, ruffled feathers, and finally dying from extreme exhaustion. Preventive measures: at 14-21 days of age, use attenuated bursal disease vaccine in drinking water, with 2% skimmed milk powder added to the water.
3. Fowl pox: caused by fowl pox virus; nodules can be seen on various parts of the sick chicken's body, and in the diphtheritic form of fowl pox, ulcers or yellowish-white lesions can be seen on the mucous membranes of the oral cavity, esophagus and trachea. Preventive measures: at 14-21 days of age, use fowl pox vaccine by wing-web stab vaccination.
II. Prevention and treatment of 3 bacterial diseases
1. Pullorum disease: caused by Salmonella, with sick chickens showing poor spirit and appetite, drooping wings, ruffled feathers, tendency to squat, and passing yellow-white or green feces. Prevention and treatment measures: use norfloxacin, ciprofloxacin or enrofloxacin in drinking water.
2. Fowl cholera: caused by Pasteurella multocida; in the most acute form sick chickens die suddenly, while in the acute form sick chickens have ruffled feathers, do not eat, breathe rapidly, discharge foamy mucus from the nostrils and mouth, pass yellow, gray or green watery feces, body temperature rises to 43°C-44°C, coma occurs, and death occurs in 1-3 days; the chronic form shows arthritis, lameness, difficulty breathing, etc. Prevention and treatment measures: after 30 days of age, intramuscular injection of inactivated fowl cholera vaccine; after onset of the disease, treatment with sulfa drugs, penicillin, streptomycin and erythromycin is effective.
3. Colibacillosis: caused by Escherichia coli; chicks show anorexia, ruffled feathers, reluctance to move, and finally death; adult chickens show atrophy of the comb, pale face, and some have diarrhea. Local infections show local clinical symptoms, such as arthritis, ophthalmitis and accompanying respiratory symptoms. For prevention, use E. coli oil-emulsion vaccine by intramuscular injection at 1 month of age; for treatment, antibiotics (such as kanamycin, neomycin, chloramphenicol and streptomycin), sulfonamides and nitrofurans are all effective.
III. Prevention and treatment of 3 parasitic diseases
These include tapeworm disease, roundworm disease and coccidiosis.
1. After chickens are infected with tapeworms and roundworms, they show stunted growth and development, pale combs, anemia, ruffled feathers, drooping wings, enteritis and diarrhea, etc. Using albendazole at 5 mg per kg of body weight can expel these two parasites.
2. Chicks from half a month to 3 months of age are most susceptible to coccidiosis, often showing symptoms such as anemia, emaciation, diarrhea and blood in the feces. Drugs for expelling coccidia include robenidine, furazolidone, qiu jing, and Sanzi coccidiosis powder, etc.