Hot and cold chickens

At the University of Manchester we are using our new infrared thermal imaging camera to keep track of how broiler chickens lose body heat. In addition to our ongoing research into the metabolic rate of broilers (see previous posts!), energy balance can be better understood by measuring how much heat is lost by the birds to the environment. We are able to track changes in heat loss as the birds age using infrared thermography. The special camera we use (FLIR i7 infrared camera) detects radiation in the infrared spectrum. Since the amount of radiation emitted by the birds increases with temperature, an image of spatial variation in temperature can be generated.

 

FLIR i7 thermal imaging camera used to photograph broilers in the lab.

FLIR i7 thermal imaging camera that is used to photograph broilers in the lab.

 

We are particularly interested in how much heat the birds lose through their legs and feet since this might affect how the birds use behavioural changes to manipulate energy consumption, i.e. if they lose too much heat via the unfeathererd portion of the lower leg (tibiotarsus) perhaps they change posture to minimise the energetic cost of maintaining a high internal body temperature. Additionally, feathers are developing fast as the broilers grow, so we can track how well insulated the bird is over development.

Here's a thermogram of a 2-week old broiler. See that the lighter colours correspond to hotter surface temperatures.

Here’s a thermogram of a 2-week old broiler. See how the lighter colours correspond to hotter surface temperatures – the legs in this bird are a main site of heat loss.

This is a 4-week old bird in a sitting posture. The feathers are more developed providing a good degree of insulation but the head and abdomen still act as areas where much heat is dissipated.

This is a 4-week old bird in a sitting posture. The feathers are more developed providing a good degree of insulation but the head and abdominal areas remain as locations where much heat is dissipated.

 

 

 

 

 

 

 

 

 

 

 

You can see how the warm bird stands out against the cooler background. Areas of interest in the photographs can be analysed to find how the surface temperature varies according to anatomical location and how this changes with ambient temperature. By taking some simple anatomical measurements such as beak, leg and foot dimensions we can estimate the heat lost to the environment using the thermal images taken with our camera.

We expect that this method will offer an interesting perspective on broiler biology, helping to understand the link between temperature, energy consumption, chicken development and anatomy.


2 Comments

  1. Nice to see that the areas covered by the wing primaries/secondaries/tertials are cooler from our point of view: they have a double dose of feathers between the skin and us.

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