Mulesing - the surgical removal of skin around a Merino sheep's breech - was developed to prevent flystrike but causes significant pain. Humane alternatives are now viable and increasingly adopted.
Mulesing represents a painful solution to a welfare problem (flystrike) that was justified when alternatives were not viable but is increasingly difficult to defend as breeding alternatives prove effective. The acute pain of mulesing without analgesia is well-documented, and its widespread performance without pain relief in Australia for decades represents a significant historical welfare failure. The use of pain relief (Tri-Solfen spray and oral meloxicam) has improved the welfare of mulesed lambs but has not eliminated pain. The availability of plain-breeched breeding lines that are comparable in production metrics to wrinkled Merinos demonstrates that the industry can transition away from mulesing without sacrificing productivity. Market pressure from major fashion and textile companies has accelerated breeding-based solutions in parts of the industry, but mulesing of millions of lambs annually continues.