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Pullets Reared in Aviary Systems - Live Vaccines

This information is NOT a housing management guide. These sections were created to help explain the relationship between housing and oocyst ingestion. Please consult your veterinarian and bird management guide from the breeding company for housing management information.


The brooding and immediate post-brooding periods are important to vaccine success because this is the time where offspring vaccine oocysts can cycle in the barn at low levels. Essentially, the cycling during this phase is acting as an immunity booster to the original vaccine dose; without this cycling, the vaccine will not work as effectively.

Note: Oocyst transmission has yet to be studied in aviary systems. Methods used with litter or cage rearing may be tried but are NOT guaranteed to work.

General Good Barn Practice Provide chicks with clean, biosecure housing. Ensure that feed and water are readily available to the chicks when they are placed (1). Additionally, proper heat, ventilation and lighting as well as feed and water quality are required for good rearing management (1).

Physical Enriched Cage Environment During Brooding: Nipple Drinker Cups If nipple cups are attached to the drinkers this is a potential reservoir for oocysts.

General Good Practice for Coccidiosis Management During Rearing

Atmospheric Barn Environment: Get to Know Relative Humidity (RH) - Because barns require ventilation, the outside temperature and humidity can impact the environment of the barn; especially if the equipment does not measure and account for RH of the air feeding the barn.

Example of the minimum outside temperature needed paired with the temperature gradient needed in a generic chicken barn over the first 6 weeks of rearing (1) to achieve an RH of 35% inside the barn (if air handling equipment does not control the RH of the air feeding the barn).


 Day 1-2

Day 3-4

Day 5-7

Week 2

Week 3

Week 4

Week 5-6

 RH (%) inside the barn








 Temperature inside barn (°C)









Dew point outside barn (°C)








Click HERE to calculate Relative Humidity.

There is not a designated optimal relative humidity percentage set-out for oocyst sporulation but an RH of 35-70% is considered adequate (bird management guides recommend between 60-70%). Interestingly, good monitoring of RH may also help the welfare of the bird (2).

Atmospheric Barn environment: Oxygen Access - If the oocyst does not have adequate oxygen access during sporulation, it may not become infective. High ammonia levels resulting from accumulated manure can also kill oocysts.

Physical Aviary System Environment: Perches, Platforms and Dust Bath Areas - As the pullets grow to use the perches, platforms and dust bath areas fecal build-up may occur on or below these additions. Consequently, it is important to note these areas as potential reservoirs for oocysts. Additionally, this elevation may allow the birds defecate on each other which could be another way in which birds could ingest oocysts (3).


Figure 1. An example of a platform in an aviary pullet rearing system during use.  Fecal build-up can occur on this platform during rearing and if the feces are contaminated with infective oocysts this platform is another area where pullets can ingest oocysts. (Picture Credit: Guy Kostrey, Sceneskape Productions)


1. Anonymous. Layer management guide: Lohmann LSL Classic. In. Lohmann Tierzucht GmBh. 2005.

2. Stamp Dawkins, M., C.A. Donnelly, and T.A. Jones. Chicken welfare is influence more by housing conditions than by stocking density. Nature 427:342-344. 2004.

3. Appleby, M.C. The Edinburgh modified cage: effects of group size and space allowance on brown laying hens. Journal of Applied Poultry Research 7:152-161. 1998.