Mary Allen
As soon as the chicks have hatched from the egg, the first diseases are already waiting for them. One of the most widespread is coccidiosis, in which mortality often rises sharply in the first few weeks. Vaccinations offer protection.
Vaccination is an integral part of rearing young chicks in commercial poultry farming. After an ingenious lapse of time, the animals in Switzerland are vaccinated several times in order to keep mortality and thus economic losses as low as possible. Vaccination is not as common among hobbyists, however, because it is often very difficult to obtain small doses of vaccine. For most vaccinations, the packaging unit is designed for a thousand animals.
In the first few days of life, chicks are at risk from three diseases in particular: coccidiosis, Marek’s disease, and infectious bursitis, also known as gumbo (see table). However, with the right prophylaxis, poultry farmers can prepare and protect their chicks from the start.
Dangerous Diarrhea
Coccidiosis is one of the most common diseases in chicks and, according to the vaccine manufacturer MSD Tiergesundheit, is one of the economically most important poultry diseases. The disease can cause high mortality during rearing and thus economic damage due to large losses in performance.
Coccidiosis is caused by protozoa. These destroy intestinal cells, which triggers the symptoms. The chicks appear sleepy and have watery to bloody diarrhea that can be fatal. The pathogens are mainly transmitted from animal to animal by picking up infected feces. The parasites can be detected in the feces or by examining dead animals. Illness can be counteracted with strict hygiene measures. However, it cannot be prevented entirely. Even in the cleanest barn, the animals can contract coccidiosis.
There are two variants of preventive measures. One of them is vaccination. It takes place between the first and the ninth day of life via drinking water. The vaccine manufacturer MSD Tiergesundheit recommends using a vaccine for breeds poultry, in particular, that is effective against all relevant coccidia species and protects the animals throughout their long lives. With the vaccine, the coccidia circulates in the herd. They are absorbed, multiply, and are excreted again. This creates immunity in the animals.
The other preventive measure is the administration of rearing feed with coccidiostats. These feed additives protect the animals from infestation and may not be used in adult animals if their eggs are intended for human consumption. If both preventive measures were used, the result would be that the feed additives would kill off the vaccine strains and the vaccination would lose its effectiveness. Poultry farmers must therefore decide on one of the two measures.
Dormant Paralysis
Marek’s disease is spread by a herpes virus and is found all over the world. The transmission of the disease occurs mainly through dust containing the pathogen. In the feather follicle dust of infected animals, the pathogen remains infectious for more than a year. Young chicks in particular are susceptible to transmission from animal to animal. With increasing age, the susceptibility of the animals decreases rapidly.
The onset of the disease is not immediate. The sick animals often only show the symptoms between the 8th and 20th week of life. In hens, the start of laying activity often leads to the outbreak of Marek’s disease. This usually manifests itself as paralysis involving the sciatic nerve and causes the young chicks to lie on their side or stretch one leg forward and one leg backward. In addition to nerve damage, tumors can also form in the most important internal organs such as the liver, spleen, and kidneys.
In many poultry farms, the animals are protected with a vaccination through an injection on the first day. Sick animals cannot be cured. In unvaccinated animals, the mortality rate is between five and 50 percent, as MSD Animal Health has determined from studies.
Persistent Virus
Infectious bursitis, also known as gumbo, is often seen in young chickens. The viral disease is highly contagious to chickens but harmless to humans and other species. The virus is difficult to get rid of in infected farms. The pathogens spread easily from animal to animal via the feces, nasal or eye secretions.
The disease occurs between the third and twelfth week of life and shows itself in dull and pale animals. The chicks crouch down, show little desire to move, and often have watery diarrhea. In a diseased stock, it can lead to severe courses with a mortality rate of five to 100 percent. The diagnosis is based on the swollen “Bursa Fabricii”, the organ above the cloaca. Since there is no treatment available, vaccinating chicks is the best preventive measure.