Pig Snout Sweat

I was out in the yard with Willie the other day, and noticed beads of sweat appearing all in a neat, straight line on the priphery of his snout stopper - so cool!

Apparently these are non-functional sweat glands, however; An e-friend offered the following:

Besides a well-developed snout, the pig has a sparse hair coat. Wild pigs actually have a thicker hair coat than domestic pigs – one assumes early pig breeders selected against a thick hair coat in common breeds. The sparse hair coat facilitates heat loss from the skin surface of the pig since the pig’s skin is open, unimpeded by hair, to evaporate water. The trouble is, the pig does not have functional sweat glands on its skin. The pig has a form of sweat gland on its skin, but they do not work. The pig can lose a small amount of water, and thus heat, through passive diffusion through the skin – but not much. So instead of sweating, the pig uses behavioral thermoregulation to cool itself. Behavioral thermoregulation is actually a more powerful mode of heat loss than is sweating – and the pig does not become dehydrated. Behavioral thermoregulation is an effective means of cooling as long as the animal has access to cool substrate.