For many centuries, numerous terms designated a “swine.” For simplicity and legibility, a swine will be referred to as a “pig” in this article.
Often, when a person thinks of a pig, they think of a fat, dirty animal, whose single use is meat production. What if that nasty animal could save a person’s life? Or what if, without them, daily conveniences wouldn’t be so convenient? The pig is often depicted as dirty, even ugly, but it is vital to the production of many convenient and lifesaving products that people use; without the pig, people would not have access to many products, such as Insulin, inkjet paper, or durable leather, not to mention the delicious lean meat.
Evolution and Domestication
It is known, through fossil recovery, that the pig has roamed the earth for nearly forty million years, and that humans domesticated them for farm use approximately eight thousand years ago. The pig was essential to pre-colonial and industrial life because it was easy to raise and an excellent source of protein. The pig was first mentioned in a printed book circa the fourteenth and fifteenth centuries, and it was often mentioned with regards to farming practices and pig-based products. In the seventeenth century, managing the pig population on a farm was very important; improper management could lead to overpopulation or underpopulation of the herd, as well as disease and famine within the farm. Ranchers, after the pig was slaughtered for meat, would tan the skin to make leather items, and would cut the hair to make brushes. In pre-twentieth century life, ranchers would organize cycles of reproduction, slaughtering, and selling of the pig for economic gain, contributing to the idea that the pig was a staple of the rural economy.
The management of the pig, both on the farm and in the economy, was crucial to ranchers. In the early days, circa the sixteenth century, the pig was not profitable for ranchers. There are many contributing factors behind this – disease was common, they were expensive to feed, and there was a negative stigma surrounding the animal. Learning how to manage and treat disease within a population was important to the economic sustainability, as this was the primary reason why pigs were a net loss. This loss in revenue forced ranchers to look for alternative uses for the pig, and so instead of slaughtering the pig solely for its meat, they started selling the skin, hooves, hair, and organs. It wasn’t until ranchers realized the value in pig by-products that the pig became incredibly profitable to the rancher, and imperative to the economy. Since the pig is biologically similar to humans, the advancements made while combating disease within a pig population were also applicable in the realm of human medicine.
Pigs and Paper
Linguistic capabilities, in terms of writing and storing information, was fostered through the alternative uses of a pig. The sixteenth century saw a surge in the literacy capabilities of people and the necessity to be able to write down and store those literary pieces. Bookmakers struggled to find a durable product to cover books, until they found pigskin. Pigskin was the perfect density and color for a book cover, as it was flat, often whiteish, and substantially thicker and more durable than parchment or vellum. Paper deterioration was another struggle bookmakers faced. Paper is comprised of cellulose fiber strands, but when left untreated, those fibers decompose and break apart. Bookmakers needed to find a material that they could use to size the paper for durability purposes. Pig hooves, teeth, and other internal structures contain protein clusters, often referred to as collagen, needed to create a gelatin-based substance that would add durability and strength to the paper through a sizing procedure. Studies have shown that when sizing a paper in gelatin it retains 56% of its fold, and when using no form of paper sizing it only retains 16% of its fold. It is because of these advancements that books from the 16th century and earlier are still alive and able to be read.
The process of sizing paper can be done internally, where the sizing agent is added directly to the vat prior to formation, or externally, where the sizing agent is applied directly to the sheet of paper post formation. Both of these methods are done by spraying or soaking the paper (cellulose) material with the sizing agent. This “sizing agent:” (gelatin-based substance) protects the inner cellulose fibers from oxidization, adds adhesive qualities, and enhances the strength and durability of the paper.
The usefulness of pigs in our lives should not be overlooked. Approximately every forty seconds, someone has a heart attack. Heparin is the leading anticoagulant, found in almost every blood thinner, used to prevent heart attacks. Heparin is also a by-product of protein fibers found in a pig. Over 182,000 heart valves are replaced in people each year, and one of the most common replacements is a heart valve from pigs. Ten percent of Americans have diabetes, which impacts their ability to regulate sugar levels, due to a failure in the production of Insulin. Pig Insulin is commonly substituted when humans cannot generate their own, saving millions of lives per year. There are around a million books published per year, and every one of those books has had some type of gelatin-based paper sizing, consisting of pig collagen. The most consumed meat in the world is pork. Many people question the importance and necessity of the pig, but question no longer, the pig is more important today than ever. From the slaughterhouse to the dinner table, or even the operating room, the pig is vital to human survival.
Presented is a selective narrative, comprised of significant events and contributions that the pig has made to society - from paper sizing to saving lives, the pig could not be more integral to daily life. Although this narrative does not address certain topics in-depth, reading the following publications can offer a deeper look into some of the topics discussed here: The Role of Gelatin in Paper Permanence, PIG 05049, An Essay on the Management of Hogs. Pigs give their meat, skin, and so much more, for the enhanced quality of life for humans – take a moment to understand and acknowledge the critical aspect the pig has in our lives.
Special Collections in Memorial Library, University of Wisconsin-Madison
Kohler Art Library University of Wisconsin-Madison
Paper Through Time by Timothy Barret, University of Iowa
Portrait of a Hog by Ladis Da Silvia, Journal of South Asian Literature