HOUSTON, April 16 — Tyson Foods and ConocoPhillips have cooked up a new recipe for your pickup truck. The two companies announced Monday that they were forming an alliance to produce and market diesel fuel made from pork, poultry and beef fat. It was another sign that farmers and agribusinesses, which are now producing corn for ethanol, will be playing an increasingly large part in the country’s energy future. The new brew should be available at the neighborhood filling station by the end of the year. The companies said that the diesel, which will be shipped and distributed through existing...