Pigs do not have fur; instead, their bodies are covered in hair or bristles. This distinction is important because while both fur and hair are made of keratin, they possess different structural characteristics and serve varied functions. The coarse covering on pigs is adapted to their environment and lifestyle, differing significantly from the soft, dense undercoat typically associated with fur-bearing animals.
Understanding Pig Coverings
Pigs possess a body covering composed of coarse hair or bristles, which fundamentally differs from the soft, dense fur found on animals like cats or rabbits. Pig bristles, particularly those longer than 5 cm growing on the neck and backbone, are primarily made of keratin, the same fibrous protein found in human hair and nails. These bristles are characterized by their stiffness, resilience, and a slightly rough texture. Unlike the softer secondary hair (wool hair) of some animals, pig bristles have a thick rind and often contain marrow, contributing to their robustness.
A single pig bristle features multiple layers, including an outermost cuticle with overlapping scales, a cortex providing strength and elasticity, and a central medulla that can be hollow or air-filled. Many pig bristles also have a distinctive trifurcate, or three-pronged, tip, which is a characteristic distinguishing them from other animal hairs. The density of pig hair can vary, with some areas like the head having a higher density of hair follicles compared to other body parts. This structural composition gives pig hair its unique feel and appearance, setting it apart from the definition of fur, which typically refers to a denser, softer, and often multi-layered coat.
The Purpose of Pig Hair
The hair covering on pigs serves several biological functions well-suited to their natural behaviors and environments. Pig hair provides insulation, protecting the animals from both cold and heat. In colder conditions, pigs can increase the insulating capacity of their coat through piloerection, where tiny muscles cause the hairs to stand upright, trapping a layer of still air close to the skin. Conversely, in warm environments, pilorelaxation flattens the hairs, reducing trapped air and enhancing heat loss.
Beyond thermoregulation, pig hair offers physical protection. The coarse bristles shield their skin from abrasions as they move through varied terrains or forage. This hair also provides defense against biting insects, which can be a significant nuisance. Furthermore, specialized tactile hairs, or vibrissae, contribute to their tactile sense. These sensitive hairs, often concentrated around the face, help pigs explore their surroundings, detect objects, and discriminate textures, aiding in their foraging activities and overall navigation.
Diversity in Pig Hair
The appearance and density of pig hair vary considerably across different breeds, largely influenced by selective breeding and adaptation to specific climates. While many common domestic pigs have relatively sparse hair, some breeds exhibit dense, unique coats. A notable example is the Mangalitsa pig, a Hungarian breed known for its thick, curly coat that can resemble a sheep’s fleece. This woolly covering is particularly prominent during colder seasons and provides substantial protection against harsh weather.
The Mangalitsa’s hair can come in various colors, including blonde, red, and swallow-bellied (black with a white belly). This breed’s distinctive coat is a result of centuries of natural adaptation to cold environments and selective breeding. In contrast, some specialized breeds are almost entirely hairless. These hairless pigs demonstrate the wide spectrum of hair coverings that can exist within the broader pig family and highlight how human intervention has influenced their physical traits.