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As a follow-up on our previous post on Management factors that cause reduced egg production in Layer Birds, we will now discuss disease factors and organisms that cause remarkable reduction of egg production in Layer birds.

Disease micro-organisms that affect poultry include various organisms of bacterial, viral, fungal, protozoan, and parasitic origin. Generally, any disease that affect laying birds consequently results to a reduction of egg production in a poultry flock. This is because once a disease affects a bird’s general well-being, it has a direct outcome on the frequency and quality of egg produced. However, some of the diseases are particularly significant in causing reduction and eventual stoppage in the production of eggs in laying birds. These include the following;

  1. Parasites

Parasites could be internal parasites (a.k.a endoparasites – parasites that lives and feed inside its host) or external parasites (a.k.a ectoparasites – parasites that lives and feed on the body of its host).  Such internal parasites include the roundworms and the tapeworms while the external parasites include lice, northern fowl mites, fleas. There are different types of anti-helminthic drugs that are commercially available to effectively and efficiently eliminates these worms. Likewise, there are insecticides and treatment regimens to manage and eliminate ectoparasites from a poultry farm.

  1. Fowl Pox:

This is a viral disease that has a characteristic scab-like lesion on the unfeathered parts of the body. There is also the wet type (diphtheritic) that affect the mucous membranes of the mouth and the respiratory tract. Fowl pox causes growth disturbance that will lead to a poor feed conversion efficiency and a consequent fall in egg production. Fowl pox can be transmitted by contact with affected birds or by biting insects.

  1. Newcastle disease

This is also a viral disease that has varying levels of virulence and pathogenicity (that is, the number of invading microorganisms and impact of the disease) on layer birds. This variation may lead to only a marked reduction in egg production, or production of rough or malformed eggs, or a complete stoppage.  Generally, Newcastle spreads rapidly and can affect the whole flock with clinical signs that include loss of appetite, coughing, depression, dropping wings, paralysis, greenish watery diarrhea. There are no effective treatments for Newcastle but laying birds could be vaccinated at the appropriate time to prevent against the disease.

  1. Avian Influenza

Avian influenza is another viral disease that affects the respiratory, digestive and the nervous systems of birds. The clinical signs that accompany Avian influenza include facial swelling, dehydration, cyanosis, coughing, respiratory distress. The severity of the disease results to a decline in the production of eggs. To prevent avian influenza, good biosecurity measures must be taken at all times on the farm.

  1. Coccidiosis

Coccidiosis is a protozoan disease of birds that affects the intestines and causes diarrhea. The disease is said to be found anywhere a poultry farm and production exists. Some of the clinical signs of coccidiosis include emaciation, diarrhea, bloody droppings, and poor feed consumption. These issues invariably leads to a marked drop in egg production in the layer birds. To prevent or manage an incidence of coccidiosis in the layer birds, there are feed additives known as coccidiostat that effectively curbs coccidiosis.

  1. Infectious Bronchitis

This is a highly contagious viral disease among poultry birds. Infectious bronchitis is characterized by respiratory signs, decreased egg production, poor quality eggs. It is imperative to know that layer birds that have been previously affected by Infectious bronchitis have high probability of being bad layer birds for life. This implies that the birds might never fully get to the optimum productivity of daily and quality egg production.


Other diseases that could result in the reduction and stoppage of egg production in layer birds include, Avian encephalomyelitis, Egg drop syndrome, Mycoplasma gallisepticum infection, fowl cholera and infectious coryza.

Conclusively, reduction or stoppage in egg production on a poultry farm can be mitigated against if adequate attention is paid to good management practices and high-level biosecurity. A poultry farm with a good biosecurity measures and management protocol will have less scourge of diseases that could cause layer birds to reduce or stop laying eggs which eventually result in economic loss for the farmer.



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