The terms “pig,” “hog,” and “swine” are often used interchangeably, leading to confusion about whether they represent different species or maturity levels. These words all refer to an animal from the same family, but their usage differs depending on size, age, and farming practices. Understanding the distinctions between these terms clarifies the language used in biology and livestock production.
The Scientific Reality: One Species, Many Names
All domesticated pigs, hogs, and swine belong to a single biological species. The accepted scientific name for the domesticated animal is Sus scrofa domesticus, a subspecies of the wild boar, Sus scrofa. Biologically, no genetic difference separates a “pig” from a “hog,” as they are simply different life stages or classifications of this one animal.
The term “swine” serves as the formal, overarching collective noun for any mammal in the family Suidae, which includes the domestic animal. Farmers and scientists commonly use “swine” as the most generic and official term for the species as a whole. Every pig and every hog is a swine. Therefore, the differences between “pig” and “hog” are based on human-assigned criteria rather than distinct biological classifications.
Defining Pig and Hog: Context and Usage
The primary distinction between a pig and a hog is typically based on the animal’s weight, size, and maturity in agricultural settings. In the United States, a widely accepted convention defines a “pig” as a younger, smaller animal, usually weighing under 120 pounds. This term generally describes animals that have been weaned but have not yet reached market weight.
A “hog,” conversely, refers to a larger, more mature animal, often weighing over 120 pounds and ready for market or slaughter. An animal classified as a hog is considered a market hog, signifying it has reached the ideal size for meat production. This distinction is mostly an industry standard, as the words are frequently used interchangeably in everyday conversation.
Gender and Age Specific Terminology
Specific names exist to denote the animal’s gender and reproductive status. An uncastrated male swine is known as a boar, especially one over six months of age used for breeding purposes. A mature female swine that has given birth to at least one litter is called a sow.
A young female that has not yet produced a litter is defined as a gilt. Conversely, a male swine that was castrated before reaching sexual maturity is referred to as a barrow. A shoat is a less common term used for a weaned, immature piglet, often weighing between 40 to 80 pounds. These precise terms allow farmers to track the reproductive cycles and growth stages of their livestock.