Wax flystrike factor: study

Wax content in the wool of Merino sheep can play an important role in reducing the incidence of flystrike, according to UWA PhD student Joseph Steer.

At the Young Agriculture Professional Forum last week at CSIRO Centre for Environment and Life Sciences in Floreat, Mr Steer said the resistant group of sheep in his study averaged 16 per cent wax content.

"In comparison, the susceptible group of sheep averaged 12 per cent," he said.

Mr Steer said higher wax content could help reduce moisture absorption but more scientific research was needed to establish a minimum average value of wax content for a flock to reduce the incidence of flystrike.

His study involved taking crutch samples from both groups to analyse wax content and fatty acid composition. The homogenised samples were also compared by counting the number of dead flies, egg masses, hatchings, and larvae numbers.

Apart from the chemical breakdown of the wool components, Mr Steer said more research into how wool absorbed and retained moisture was essential because these determined the desiccation of eggs, larvae and induction of oviposition.

Using analytical methodology to compare faecal and wool samples, Mr Steer found flies were more attracted to the latter, suggesting flystrike was influenced by the wool component.

"But I feel what is more important than the wool is what the skin is doing," he said.

"The skin, which produces the wool, is a living component capable of altering in response to flystrike."