Egg Industry Center to Fund Research on Air Quality in Aviaries


The Egg Industry Center will offer challenge grant awards to develop proposals to investigate air quality in a aviaries. The issue arises from 2016 data collected by scientists conducting a research project comparing conventional cages, enriched colonies and aviaries under the auspices of the Coalition of Sustainable Egg Supply. In the event, the study was seriously flawed by high mortality in the pullets transferred from rearing to the laying aviary. This was a function of mismanagement, incompetence and a disinclination to follow the advice of specialists. Early mortality as a result of dehydration, persecution obviously impacted the financial return from the aviary group.

EGG-NEWS commented adversely on the results obtained by the scientists concerned and advised that the calculated financial return should have been adjusted to account for mortality. The only conclusion that could have been derived from the study was that dead hens do not lay eggs.

The selection of air quality which the EIC Advisory Board considered “a challenge” is in all probability spurious. Effective ventilation in houses or compartments containing upwards of 100,000 hens, if adequate in terms of fan capacity and with effective control systems is not responsible for either particulate contamination or ammonia levels which are injurious to flocks or caretakers.

There are far more important aspects of aviary housing which should be evaluated. Based on experience, shell damage is an important consideration with some operations experiencing in excess of 15 percent downgrades. Investigation shows interactions between strain, equipment design, lighting, management of the flocks and operation of egg collection and rate of grading.

Each one percent increase in shell downgrades on a complex of one million hens represents a loss of $250,000 annually given an average of 80 percent hen-week production and a nominal nest-run value for cage-free eggs of $1 per dozen.

Shell damage in aviary housing is a complicated issue and may involve defects in the design and installation of curtained nesting areas; transport of eggs on belts over distances exceeding 400 feet; damage on elevators which may move eggs among four levels and the design and operation of graders extending from accumulator tables through to crack detection.

Soiling of eggs may be a substantial cause of downgrading. This is in part due to floor laying. Surely research should be extended to causes and prevention of the source of loss through downgrades. The intensity and spectrum of light, positon of lamps in aisles, strip lighting on tiers  and under-module illumination should be evaluated to provide appropriate recommendations to producers as they transition from conventional cage housing in high-rise units to modern aviaries.

There is little work on the welfare and production aspects of multi-tier aviary installations. It appears that the industry is moving from three-tier to two-tier configurations, that with limited experience reduce the tendency of flocks to concentrate on the highest level where there is imperfect visualization of flocks and imbalanced stocking density within the house.

 If the Egg Industry Center assigns a considerable sum of money to a consortium to evaluate air quality, which may in fact not be a problem, other more pressing and financially significant problems associated with aviary housing will be neglected. In any event, the time required to plan and execute a field trial on the atmosphere of aviary houses and the prolonged period for scientific groups to analyze and publish their results will be of little immediate benefit to the industry. The proposed study will not contribute to the mission of the EIC, which is to acquire and disseminate science-based information for the benefit of producers.