Winter worming in sheep – Why timing matters

As temperatures drop, it can be easy to assume parasite pressure slows down completely through winter.

But while seasonal conditions change, internal parasites can still impact feed conversion, condition and overall production performance, particularly in young stock or higher challenge environments.

Winter worming is not just about treating parasites. It is about protecting performance during a time when feed quality, nutritional demand and seasonal pressure can already place livestock under additional stress.

Why worm burdens still matter through winter

Internal parasites can quietly impact productivity without always causing obvious clinical signs.

Reduced growth rates, poorer feed utilisation and animals struggling to maintain condition can all point to underlying worm burdens limiting performance.

Young stock are often more vulnerable during this time, particularly where pasture contamination levels remain high or seasonal conditions place additional pressure on nutrition and growth.

In higher rainfall or ongoing challenge environments, worms such as barber’s pole worm, brown stomach worm and black scour worm may still remain relevant through cooler months.

Even low-level burdens can impact how efficiently sheep convert feed into growth and production. Protecting feed conversion becomes particularly important through winter when feed costs increase and pasture quality begins to decline.

Why timing matters

Strategic winter worming is not simply about following a routine treatment calendar.

It is about identifying periods where intervention is likely to protect performance, reduce pasture contamination and support livestock through seasonal pressure.

Well-timed treatments may help reduce the impact of existing burdens before animals enter more demanding periods such as late pregnancy or poorer seasonal feed conditions.

Where long-acting treatments fit

Long-acting parasite control products can play a role in helping manage ongoing worm challenges while reducing repeated handling and treatment pressure.

Products such as the new Moxistar Long-Acting Injection for Sheep provide extended activity against key internal parasites in sheep and may assist in maintaining protection through periods of ongoing exposure.

As with any parasite management strategy, treatment decisions should be guided by seasonal conditions, risk profile and overall production goals.

Winter worming is not just about parasite control.

It is about protecting condition, feed conversion and overall production efficiency during the colder months.