Battery cage chinchilla and foxes in fur farming, and most recently for the Asian palm civet for kopi luwak production of coffee. An early reference to battery cages appears in Milton Arndt's 1931 book, "Battery Brooding", where he reports that his cage flock was healthier and had higher egg production than his conventional flock. At this early date, battery cages already had the sloped floor that allowed eggs to roll to the front of the cage, where they were easily collected by the farmer and out of the hens' reach. Arndt also mentions the use of conveyor belts under the cages to
Cellular waste product as well as by cells called anaerobes that selectively perform anaerobic respiration even in the presence of oxygen. In anaerobic respiration, weak oxidants like sulfate and nitrate serve as oxidants in the place of oxygen. Generally, in anaerobic respiration sugars are broken down into carbon dioxide and other waste products that are dictated by the oxidant the cell uses. Whereas in aerobic respiration the oxidant is always oxygen, in anaerobic respiration it varies. Each oxidant produces a different waste product, such as nitrite, succinate, sulfide, methane, and acetate. Anaerobic respiration is correspondingly less efficient than aerobic respiration. In the absence