It is shown that a singular second moment matrix with rank one may induce properties of a control system in a first order autoregressive time series. A growth law is associated with the non-unity root of the recursive system, so that it can be described by a single dimensional Markov process. Control laws are furthermore associated with the unity roots of the recursive system and their vectors, with special reference to the partitioning of feed intake energy into heat production and the deposition of fat and protein. It is shown that the time series description can be transcribed to an optimal linear discrete time feedback control system.