High mortality, decreased feed intake, lower than expected body weight gain, poor feed efficiency, reduction in egg production and poor eggshell quality are common adverse effects of heat stress often seen in meat- and egg-type poultry flocks.

Heat stress in commercial poultry farms is again at the center of attention, and for this reason I thought it would be a good time to briefly talk about heat stress. 

High mortality, decreased feed intake, lower than expected body weight gain, poor feed efficiency, reduction in egg production and poor eggshell quality are common adverse effects of heat stress often seen in meat- and egg-type poultry flocks.

The magnitude of heat stress-related problems may vary from region to region and from one farm to another (in the same region). These effects may not even be the same in different barns of a farm. There is no doubt that temperature itself is a determining factor, but farm structure (house design, ventilation system, stocking density, etc) and the way that farm managment/staff handle heat stress are also important and can affect the outcome of this problem. Additionally, birds - depending on type and stage of production - react differently to heat stress conditions. You may not expect to encounter similar adverse effects in a 4-week-old broiler flock and a 40-week-old broiler breeder flock.

There are many publications on how we can reduce or minimise adverse effects of heat stress on birds in commercial poultry operations. Strategies such as temporary feed restriction or feeding at specific times of the day, increasing density of nutrients in diet (because feed intake decreases during heat stress), providing birds with extra electrolytes and vitamin (especially through drinking water), and changing the lighting programme may all be helpful in managing heat stress-induced problems in poultry. It is always recommended to provide birds with cool water, but I am not sure how this can happen when the temperature is 50ºC.

1. How do you specifically deal with heat stress in your farm?

2. As today's birds are genetically selected for different traits, do you think that selection for heat tolerance could lead us to some point to be able to cope with heat stress?