Suspension of Zilmax sales prompts shortage of rival cattle feed additive

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.

Zilmax became the focus of attention in the livestock industry after Tyson Foods Inc said it will stop buying Zilmax-fed cattle for slaughter beginning next month. Tyson, the biggest US meat processor, said it was concerned about Zilmax potentially causing health problems for some cattle.

Last week Merck said it was temporarily suspending sales of the product in the US and Canada.