[1] Examples are meat, fat, blood, milk, eggs, honey, and lesser known products, such as isinglass, rennet, and cochineal.
Increased production and consumption over the past 50 years has led to widespread environmental and animal welfare impacts.
These range from being linked to 80% of Amazonian deforestation[3] to the welfare implications of using chick culling shredders on live day old-chicks for 7 billion of them each year.
[10] It uses between 20 and 33% of the world's fresh water,[11] Livestock, and the production of feed for them, occupy about a third of the Earth's ice-free land.
[20] Habitat is destroyed by clearing forests and converting land to grow feed crops and for grazing, while predators and herbivores are frequently targeted because of a perceived threat to livestock profits; for example, animal husbandry causes up to 91% of the deforestation in the Amazon region.
Standards and laws for animal welfare have been created worldwide, broadly in line with the most widely held position in the western world, a form of utilitarianism: that it is morally acceptable for humans to use non-human animals, provided that no unnecessary suffering is caused, and that the benefits to humans outweigh the costs to the livestock.
[26][27][28][29][30] Live export of animals has risen to meet increased global demand for livestock such as in the Middle East.
[34] Animal by-products, as defined by the USDA, are products harvested or manufactured from livestock other than muscle meat.
[37] Slaughterhouse waste is defined as animal body parts cut off in the preparation of carcasses for use as food.
[38] Many large, well-known pet food brands use animal by-products as protein sources in their recipes.
This can include animal feet, livers, lungs, heads, spleens, etc or an admixture in the form of meat and bone meal.