Animal by-products include: leather, wool, feathers, bone (for products such as gelatin), intestine and catgut (for sausage casings, instrument strings, rennet for cheese manufacture), hair (for brushes and furniture padding), blood (for animal feedstuffs), animal fats and lycerine (in confectionery and cosmetics). In addition to these more obvious products, many others are used in the manufacture of consumer goods considered essential to life although no mention of the animal origin is made on the label. Animal products are also widely sort as status symbols (rhinoceros horns as dagger handles), as trophies (animal heads, antlers, skins), as collectors items (birds eggs), as aphrodisiacs (horn), and as fashion accessories (fur).
In China, donkey skins are boiled to produce a brown gelatine, which is the essential ingredient in Chinese "ejiao" products - popular health foods and traditional medicines; ejiao gelatine can sell for up to $388 per kilo. China's donkey population dropped from 11m in 1990 to 3m in 2017. Suppliers now import skins from elsewhere, particularly Africa where the animals are such an important part of life for transport and farming in poorer communities. 1.8m skins are traded every year - according to estimates from UK-based charity The Donkey Sanctuary - but the demand is as high as 10m. Uganda, Tanzania, Botswana, Niger, Burkina Faso, Mali, and Senegal have banned donkey exports to China.