Animal Science

Humans vs. Cows

Ever wondered why people require coats and scarves to stay warm during the winter, while animals go without any clothes at all? Me, too.

​

Us humans have less fur a.k.a. more exposed skin to the environment than cows do. This increases the surface area from which heat is lost since we do not have an insulating layer of fur to trap the warm air against our bodies.

​

This picture is from a cold winter morning out at the calving barn. This human (me) had to bundle up with four layers of clothing in order to keep from shivering. The calf, on the other hand, seems to be doing just fine with his thick, furry hair coat. His TNZ is clearly lower than mine.

Incubators

On the other end of the spectrum, newly hatched chicks have a very high TNZ. They would surely freeze and die in the conditions that the calf was born into. They are most comfortable in an ambient temperature in the range from 99-102 degrees Fahrenheit to survive their early days. 

Pigs

Piglets share the chick's affinity for high temperatures at a young age. As the animal grows older its TNZ gradually decreases. This is because metabolic processes in older pigs contribute significantly to heat production and regulation. (This happens with mature poultry as well)

House pets

Our pets have grown accustomed to the preferred ambient temperature of their resident humans, yet are often still able to survive comfortably in a wider temperature range than humans can. This is because the TNZ is a product of both acclimatization to an environment AND inherited traits.