Merck & Co’s decision to suspend sales of its Zilmax cattle feed additive has caused such a surge in demand for rival Eli Lilly & Co’s Optaflexx that Lilly is telling some new customers it cannot immediately supply them, some US-based customers have told Reuters.

CATTLE farming may have peaked “forever” in the US, according to an industry leader. Higher input costs will force ranchers into long-term herd reduction, processors will reduce excess capacity, and consumers will pay more for beef, said Dick Bond, chief executive of Tyson Foods Inc, the largest US meat processor.