Coccidiosis E. necatrix, Mid Intestinal, in Laying Hens
Layer pullets suffering outbreaks at 7-20 weeks of age or even hens during the egg production may suffer mortality, loss of uniformity and decreased egg-laying potential. (1, 2)
Coccidiosis rarely occurs in layers and breeders during the laying cycle, because of prior exposure to coccidia and resulting immunity, if a flock is not exposed to a particular species early in life or immunity is depressed because of other diseases, outbreaks may occur after layers are moved to production houses. Outbreaks of any species in layers can reduce or eliminate egg production for several weeks (1, 2)
E.necatrix along with E.tenella is the most pathogenic of the chicken coccidia. Droppings of infected birds often contain blood, fluid, and mucus. Some birds may show ruffled feathers. (1, 2)
Infections with mid-intestinal species of coccidia are a major predisposing factor for Clostridium sp. infection. Colonization of small intestine by Eimeria sp. may lead to intestinal mucosal damage which may then, in turn, provide natural substrates (plasma proteins) required for Clostridium sp. proliferation. (1, 2)
Observed Clinical Signs Happenings
- Egg production drops gradually
- Decreased egg-laying potential
- Low mortality or increases gradually
- Good bodily condition (“full crop”)
Visibly sick birds
- Few visibly sick birds
- Droppings of infected birds often contain blood, fluid, and mucus
- Ruffled feathers
Coccidiosis E. necatrix, Mid Intestinal, in Laying Hens DOES NOT exhibit or manifest any of the following clinical signs happenings:
- Egg production declines rapidly
- High mortality or increases rapidly
- Dead birds
- Poor bodily condition (“Skinny body”)
- Many visibly sick birds
- Flock behaviour activity change
- Respiratory abnormalities
- Neurological Nervous
- Lameness or unusual movements, incoordination, ataxia
- Eyes abnormalities
- Head, Comb, Wattles, Face, Nostrils, Sinuses, Mount, Beak, Earlobes, abnormalities (except eyes)
- Body Parts (Neck, wings, breast, abdomen, shanks, legs, hocks, feet, joints, vent, and skin, abnormalities), skinny body, retarded growth, weight depression
- Feathers abnormalities
- Feed Consumption Changes
- Diet or Feed Changes (Recent Feed delivery, Recent formulation /diet, Other silo or improper storage, another feed brand)
- Shell quality defects
- Internal Egg defects
- Causing Agents
- Protozoal Infection parasites . E. necatrix. Small parasite found in the intestine and caecum
- Affected Systems/Organs
- Intestinal tract. Small Intestine (middle).
- Infective agent is found in litter, droppings and contaminated objects. Spread is primarily via the faecal-oral route
- Mainly Affects
- Liveability and Egg production Potential. The extent of the disease is proportional to the amount of infective agent ingested
- Adequate Pullet coccidial immunization program. Anticoccidial drugs. Good hygiene practices, vaccinations, coccidiostat in feed or water.
- Suggested Actions
- Can be managed with feed additives, off-the-shelf medications
- Can be managed with vaccination programs
- Diagnosis should be confirmed with rapid assays and/or a certified laboratory
- Veterinary intervention is recommended
Impact on Egg quality
Impact on Liveability
Impact on Production
Overall Economic Impact
- Y.M. Saif.2008.Disease of Poultry. 12th Edition. Page
- David E. Swayne. 2013. Diseases of Poultry 13th Edition. page
- Mark Pattison, Paul F. McMullin, Janet M. Bradbury. Dennis J. Alexander. 2008. Poultry Diseases. 6th Edition.
- Paul McMullin. 2004. A Pocket Guide to Poultry Health and Disease. First Edition.
- Steven Leeson, John D. Summers. 2008. Commercial Poultry Nutrition. Third Edition.
- Donald D. Bell, Williams D. Weaver. 2009. Commercial Chicken Meat and Egg Production. Fifth Edition.
- Gail Damerow 1994. The Chicken Health Handbook.