by Lisa Heinzerling When an agency defends over three decades of inaction on an important problem by saying that acting would take too long, one hopes a judge reviewing the agency’s inaction will see through the pretense. This is exactly what happened this week, when a federal magistrate judge in New York ruled that the U.S. Food and Drug Administration had acted arbitrarily in citing time and resource constraints in declining to limit the use of antibiotics in animal feed. Some 80 percent of the antibiotics used in the United States are given to animals destined to become part of…