As ventilation settings shift from winter minimums to transitional airflow, litter tends to dry out, dust levels rise, and airborne irritants become more prevalent. Dust particles carry a cocktail of threats— ammonia, bacteria, fungal spores, and endotoxins—that can irritate the respiratory tract and compromise mucosal defences. In free-range systems, where birds are exposed to wider pathogen pressures and variable weather, these airborne risks can quietly erode flock performance.
Mild respiratory irritation may not always present clearly, but the effects are visible in shell quality, feed conversion, and persistency of lay. Once inflammation sets in, nutrient absorption can suffer and shell deposition becomes less consistent. This is especially relevant in flocks already past peak, where even small dips in resilience can lead to higher seconds and rising mortality.
Ventilation is the starting point. Free-range houses often struggle with airflow uniformity, particularly where pop-holes introduce cold drafts or cause dead spots in the shed. Regular checks on in-house temperatures, airspeed, and humidity—alongside simple dust plate monitoring—can highlight issues before they escalate. Adjustments to inlet angles and fan run times may be needed as the weather turns warmer, especially on still days.
From a nutritional standpoint, support for the respiratory and immune systems can help mitigate airborne stress. Vitamins A and E are central to mucosal health, while selenium and zinc support immune responsiveness. Levels should be reviewed during periods of increased dust or mild respiratory challenge, as birds’ requirements often exceed baseline inclusions when under pressure.
Managing litter condition is just as important. Excessively dry litter increases dust load, while wet patches around drinkers raise ammonia levels. Small adjustments in water pressure, sodium content, or feed texture can help stabilise litter quality without impacting intake.
Heading into spring, performance targets naturally take centre stage— but air quality shouldn’t be an afterthought. For free-range flocks to stay productive and resilient through the season, the air they breathe matters just as much as what they eat.