Repsol YPF

Definitions

Domestic animals are hometherms, which is to say, they must keep their body temperature within a narrow range. This obliges them to maintain a balance between the heat they lose to the outside environment and the heat they receive from their environment or produce themselves.                     

There is an environmental temperature range within which heat produced is enough to keep the body temperature constant. This temperature range is called neutral temperature. 

When the surrounding temperature falls below neutral, animals need to produce more heat to keep their body temperature constant. To do this, animals eat more food. If this is not possible, they obtain heat by burning the reserves in their own bodies, thus reducing breeding productivity. Temperatures below the neutral range are termed critical low temperature.

When the temperature of the surroundings is higher than the neutral range, animals balance their body temperature by releasing heat into the environment. This is a waste of energy that does not lead to production. Temperatures above the neutral range are termed critical high temperature.   

Within one animal species, critical low and high temperatures vary according to breed, age, amount and quality of food, and environmental conditions. Within neutral temperature range, optimum temperature is that which results in the best transformation rates.