On June 3, 2026, the US Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) confirmed a case of New World Screwworm (NWS) in a 3-week-old calf in Zavala County, Texas, the first confirmed US case in decades, prompting responses from government and industry groups.
The larvae were detected in the calf’s umbilical area. As of now, no additional cases have been reported.
NWS is a destructive pest that can infest livestock, pets, wildlife, and, in rare cases, humans. The larvae feed on living tissue, causing severe wounds, animal health concerns, and significant economic losses.
Impact on cattle futures
Feeder cattle futures on the Chicago Mercantile Exchange (CME) opened sharply lower on Thursday as traders reacted to news of a confirmed case. Contracts later pared losses and moved sharply higher into positive territory following two consecutive days of steep declines linked to NWS concerns. Market participants cited ongoing uncertainty about US cattle supplies and movement restrictions following the reported case.
Earlier in the session, August feeder cattle fell to their lowest level since mid-April before recovering and reversing Wednesday’s losses. Live cattle futures also posted gains, rising between $1.575 and $2.375 at last check and forming bullish outside reversals.
In late 2024, the USDA imposed a ban on livestock imports from Mexico in an effort to contain the spread of the parasitic fly. The border was briefly reopened before being shut again in May of last year. Prior to these disruptions, the United States typically imported about 1.2 million feeder cattle annually from Mexico. Those animals are then fattened in US feedlots for up to six months before being sent to slaughter.
The US cattle herd remains at 75-year lows after ranchers sharply reduced herd sizes due to drought conditions.
While drought conditions have eased in recent weeks, they remain significantly higher than a year ago, with more than half of US cattle inventory currently in drought-affected areas, according to recent government data, compared with about 21% a year earlier.
Take action
If you want to see how exposed your supply book is – and what practical steps to take next – request a demo. We’ll show you real‑time price impacts, alternative supply options and a playbook to reduce disruption while the eradication effort continues.
Written by Courtney Shum
