Discuss briefly: (a) Temperature; (b) Relative humidity; (c) Light; in relation to poultry production and state two ways of controlling the effect of each.

Environmental factors in poultry production

(a) Temperature

Temperature affects feeding, growth, egg production and comfort of birds. Very high temperature causes heat stress, reduced feed intake, panting and lower egg production, while very low temperature (especially for chicks) causes chilling, huddling and death.

Two ways of controlling its effect:

• Provide brooders/heat sources (lamps) to warm chicks in cold conditions.
• Provide adequate ventilation, shade and cool clean water, and orientate/insulate the house to reduce heat.

(b) Relative humidity

High relative humidity makes litter damp and cakey, encourages ammonia build-up, moulds and disease, and hampers heat loss from birds. Very low humidity causes dusty conditions and dehydration.

Two ways of controlling its effect:

• Provide good ventilation (open sides, fans) to remove excess moisture.
• Keep the litter dry by regular turning/replacement and avoid water spillage.

(c) Light

Light stimulates activity, feeding and, importantly, the reproductive system, thereby influencing sexual maturity and the rate of egg laying. Too little light reduces egg production; excessive/uncontrolled light can cause restlessness and vices such as cannibalism.

Two ways of controlling its effect:

• Provide artificial (electric) lighting to supplement day length and stimulate laying.
• Regulate the light duration and intensity using timers, dimmers or by curtaining/shading the house.