Poultry CRC CEO, Mingan Choct

A survey of farms across the Australian broiler industry was conducted to establish the prevalence of serotype 1 Marek’s Disease virus (MDV1) in dust collected from the sheds at the end of the batch and to identify risk factors associated with this prevalence.

The survey included up to 4 sheds on each of 72 farms (288 sheds in total) involving 8 broiler companies. Industry cooperation was exceptional with a 90% response rate and all states were included.

Data were collected using a comprehensive management and performance questionnaire covering factors including proximity to other farms, biosecurity practices, hygiene, HVT vaccination, shed design and ventilation, brooding, bird density, chicken strain and bird performance (mortality, growth rate, FCR).

Factors identified as significant risk factors for the presence of MDV1 in dust were birds hatched in summer-autumn, farms with more than 4 sheds and farms with another chicken farm within 2 km.

The provision of clothing for visitors on farm and using wood-based litter (compared to straw or rice hulls) were found to be protective against the presence of MDV1 in dust.

MDV1 was not ubiquitous on broiler farms, contrary to conventional wisdom.

Poultry CRC CEO, Mingan Choct, said industry is already successfully using results from Project 3-27, which investigated dustbath materials for health and welfare in layers.

“The litter material is usually the first point of contact for the birds in the shed and therefore it becomes the first ‘food’ item for them,” said Mingan.

“As we have shown, birds eat a significant amount of litter, and hard litter materials, such as wood shavings, are good for gut development.”

“A more robust gut usually means a more resilient animal.”