Humans and animals share a long and complex relationship, evolving from basic necessity to specialized partnership. For millennia, animals have been integrated into nearly every facet of human existence, providing resources, labor, and knowledge that shaped civilization. These interactions cover a spectrum of roles, from the global industrial system of food production to modern scientific research. Understanding the scope of animal use today reveals how deeply their contributions remain woven into the fabric of modern society.
Providing Sustenance and Raw Materials
The most widespread use of animals globally centers on providing food and industrial materials through animal agriculture. This massive system supplies meat, dairy, and eggs, sustaining billions of people worldwide. At any given time, an estimated 31 billion land animals are being farmed, with fish accounting for an additional 38.8 to 215.9 billion individuals globally, underscoring the immense scale of this production. Animal agriculture occupies 77% of the world’s agricultural land, primarily for grazing and growing feed crops.
Beyond nutrition, animals provide a surprising array of raw materials used in countless consumer and industrial products. Non-food items derived from livestock include fibers such as wool, cashmere, and silk, as well as hides used to produce leather and suede. By-products from the slaughter process yield fats like tallow and lard, which are used in cosmetics, soaps, and even polymer banknotes.
Specialized materials are also extracted from animal sources for use in manufacturing and medicine. Gelatin, derived from collagen found in the skin and bones of cattle and swine, is used in food, photographic film, and pharmaceutical capsules. Other components include lanolin from sheep’s wool, used in moisturizers and lubricants, and casein, a milk protein used in glues, plastics, and paints. Even insects contribute, with carmine, a vibrant red pigment derived from crushed cochineal beetles, used as a dye in foods and lipsticks.
Supporting Labor and Human Assistance
Animals have historically provided the muscular power necessary to build and maintain human societies. For centuries, species like oxen, horses, and water buffalo served as draft animals, plowing fields, turning mills, and transporting goods and people. Though mechanical transport has replaced much of this labor, horses and donkeys continue to be used for transportation and hauling in many parts of the world, particularly in arid or underdeveloped regions.
Modern working animals are defined by their sensory capabilities, particularly their acute sense of smell. Highly trained dogs are deployed by police and military units for detection tasks, including locating narcotics, explosives, and accelerants with precision unavailable to human officers. These canines also play a role in search and rescue operations, working to find missing persons following natural disasters or in wilderness environments.
A separate category of working animals provides individualized assistance to people with disabilities. Service dogs are trained to perform tasks that mitigate the effects of a person’s disability, such as guiding the visually impaired or alerting a handler to a low blood sugar level. This functional role distinguishes them from emotional support animals, whose contribution is providing comfort and companionship.
Advancing Scientific and Medical Knowledge
The use of animals in controlled laboratory settings is rooted in the biological similarities they share with humans, making them effective models for studying disease and testing new treatments. Mice, rats, and other small mammals are the most commonly used species in biomedical research. Their short life cycles allow scientists to study diseases that develop over long periods in humans, such as cancer and Alzheimer’s disease.
Animal models are used throughout the drug discovery process, from basic research to safety testing. Researchers develop induced disease models in healthy animals to study the mechanisms of human conditions, or they use genetically modified models to investigate the role of specific genes in disorders like autism. Toxicology testing requires animals to assess the safety and potential side effects of new chemical compounds and pharmaceutical drugs before they can be administered to human subjects.
The goal of this research is to understand how potential medicines are metabolized and distributed throughout the body, and to identify any adverse effects in major organ systems. Animal models have aided the development of vaccines, surgical techniques, and treatments for human and animal diseases, but the process is governed by strict ethical frameworks. Scientists are required to adhere to the “3Rs” principle—replacement, reduction, and refinement—to minimize the number of animals used and improve their welfare.
Facilitating Recreation and Companionship
Animals are integrated into human life for enjoyment, emotional connection, and leisure activities. The most prevalent form is companionship, where pets like dogs, cats, fish, and birds are welcomed into homes. This relationship provides emotional support and psychological benefits, offering comfort and joy from caring for and interacting with a companion animal.
Beyond the home, animals are central to various forms of organized recreation and entertainment. Structured environments such as zoos and aquariums allow the public to observe and learn about species from around the world, contributing to conservation awareness. Competitive sports involve animals in events like horse racing, show jumping, and other equestrian disciplines, where they are trained to achieve peak athletic performance.