Chicken fat is fat obtained (usually as a by-product) from chicken rendering and processing. Of animal-sourced substances, chicken fat is the highest in linoleic acid (over 23%). It is often used in pet foods, and has also been used in the production of biodiesel. Chicken fat is one of three types of animal fat referred to as Schmaltz, the others being goose and pig or pork fat. Food which is rendered inedible by use of chemical or physical means which affect its palatability or appearance to a degree which makes it unappealing or even toxic. An example of such implementation is adding Denatonium (which is normally used for poison) to food used for laboratory purposes where human consumption is not intended. Another example is denatured alcohol.