Recently, there has been some concern about energy utilization in agricultural production. Shortages of natural and LP gas have affected many livestock producers, especially swine producers utilizing LP gas as a supplemental heat source in farrowing facilities. These shortages, coupled with an ever-increasing price for fuel and electricity, have encouraged many producers to begin looking for alternative energy sources.
Fehr, Robert L., "Energy in Agriculture: Energy for Swine Facilities Part II: Alternative Sources of Energy" (1978). Agricultural Engineering Energy Series. 35.