Chicken is one of the most versatile animals on the planet, used far beyond the dinner table. While cooking is the most obvious application, chicken and its byproducts play roles in vaccine manufacturing, joint health supplements, cosmetics, pet food, biodiesel production, biomedical research, and even cultural rituals. Here’s a closer look at each major use.
Food and Nutrition
Chicken is the most widely consumed meat in the world, and its nutritional profile explains why. A 3-ounce serving of roasted chicken breast contains about 24 grams of protein and only 3 grams of fat, with 170 calories. Chicken thigh delivers a similar 23 grams of protein but with 9 grams of fat and 210 calories per serving. Both cuts provide zero carbohydrates, making chicken a staple in high-protein and low-carb diets.
Globally, chicken appears in an enormous range of cuisines and preparations: roasted, grilled, fried, braised, stewed, ground into sausages, dried into jerky, or simmered into broth. Chicken stock forms the backbone of soups, sauces, and risottos in nearly every culinary tradition. Global meat production reached an estimated 365 million metric tons in 2024, with poultry accounting for a major share of that growth.
Flu Vaccine Production
Every year, billions of fertilized chicken eggs are used to manufacture influenza vaccines. This egg-based process has been the standard method for more than 70 years. Vaccine manufacturers inject candidate virus strains into fertilized eggs, incubate them for several days while the virus replicates, then harvest the fluid. For standard flu shots, the virus is killed and purified. For nasal spray vaccines, a live but weakened version of the virus is used instead.
This process requires enormous quantities of eggs, which is one reason flu vaccine production takes months and must begin well before flu season starts. While newer cell-based and recombinant methods exist, egg-based manufacturing still produces the majority of flu vaccines distributed in the United States.
Joint Health Supplements
Chicken sternum cartilage is the primary source of a supplement called undenatured type II collagen, commonly labeled UC-II. This powdered ingredient provides glycine and proline, two amino acids important for cartilage stability and renewal. A typical supplement capsule contains about 40 milligrams of UC-II material, delivering roughly 10 milligrams of native type II collagen.
UC-II has been studied primarily in animals with osteoarthritis, where it reduced lameness and pain during movement. Regulatory agencies have recognized it as generally safe for human consumption, and it’s now a common ingredient in joint health products marketed to people and pets alike.
Pet Food
Chicken is one of the most common protein sources in commercial pet food. Beyond whole chicken meat, the industry relies heavily on poultry by-product meal, which the Association of American Feed Control Officials defines as the ground, rendered parts of a slaughtered chicken carcass: necks, feet, undeveloped eggs, and intestines. Feathers are excluded except in trace amounts unavoidable during processing. This meal provides concentrated protein, fat, calcium, and phosphorus, making it a cost-effective and nutrient-dense ingredient for dogs and cats.
Industrial Uses of Feathers and Fat
Chicken feathers, which are about 90% keratin protein, have become a surprisingly valuable industrial material. Rather than ending up in landfills, processed feathers now serve as raw material for animal feed supplements, biofertilizers, cosmetics, bioplastics, and even textile fibers. Feather keratin can be broken down into peptides that show up in skincare products. Low-molecular-weight keratin peptides have demonstrated skin health benefits and water-retention properties, making them candidates for anti-aging creams and hand care products. Keratin-based enzymes are also used in dehairing creams, nail treatments, and acne and scar products.
Chicken fat, meanwhile, can be converted into biodiesel through a chemical process called transesterification. Rendered fat from processing waste is combined with methanol and a catalyst to produce fuel. Blending 10% chicken fat biodiesel into conventional diesel doesn’t significantly change engine torque, though fuel consumption rises by about 6.3% because biodiesel has a lower energy density. On the emissions side, carbon monoxide and hydrocarbon output drop by 15% and 10% respectively, though nitrogen oxide emissions increase by about 10%.
Biomedical Research
Chicken embryos have been a cornerstone of developmental biology for over a century. The chicken genome was fully sequenced and published in 2004, which reinforced the species’ importance as a research model. Scientists favor chicken embryos because they’re inexpensive, easy to access and manipulate, and develop in ways that closely mirror early human organ formation. Researchers can observe heart development, neural tube formation, and blood vessel growth in real time. The eggs essentially function as self-contained, transparent laboratories, making them especially powerful for cardiovascular research and genetic engineering studies.
Cultural and Ritual Significance
Chickens have carried symbolic weight across cultures for thousands of years. Ancient Romans used them as oracles, interpreting divine will by observing how sacred chickens ate or how they moved in flight. This practice, called alectryomancy, predates modern poultry farming by millennia.
In Jewish tradition, a ritual called kapparos involves swinging a rooster overhead on the afternoon before Yom Kippur as a symbolic transfer of sins. The meat is then given to the poor for their pre-fast meal. Across Southeast Asia, roosters hold deep significance in animist fertility beliefs and sacred cockfight rituals. In Balinese Hinduism, certain funeral ceremonies within the Toraja society include cockfights as part of the religious observance. These traditions reflect how central the chicken has been to human spiritual life, not just human nutrition.