Chickens have become emblematic of the Anthropocene: They embody the age of acceleration, (post-) industrial value, and intensification in scientific and technological knowledge and practice. Contemporary chickens are the bearers of significant genetic and nutritional knowledge, experimented upon and ‘tweaked’ so much so that some have denied that contemporary commercial chickens are chickens at all. This article reconsiders chickens through a metabolic lens, and the notion of metabolism through chickens, arguing that attending to chickens opens up new conceptualizations of life and labour in the metabosphere. The article tells a metabolic history of chickens from ornament to enclosed monocrop, by way of the laboratory and nutritional experiments. Then, it looks at chicken metabolism in three conceptual modes: first, as a conduit for value, metabolizing and enhancing human life for the past century; second, through technological innovations extending the gut outside chickens’ immobilized bodies; and third, through the planetary impacts of metabolic porosity in geological manifestations, toxic atmospheres, and viral overflow. Ultimately, this article shows how techno-scientific production of chickens has taken place in and created the metabosphere as a site of experimentation and exploitation.