Researchers, consultants and others working in Australian states have developed worm management programs and information documents that will assist you to effectively manage worms on your property.

This information is additional to the information in the 'Ask the Boss' section of WormBoss which mainly focuses on the 'drenching decision' part of worm management.

Queensland is a summer rainfall area. The rainfall distribution divides the sheep raising districts into two zones:

• the vast western pastoral zone and;
• the smaller SE Maranoa / Darling Downs zone

The Great Dividing Range forms a natural barrier between the drier inland grazing area and the higher rainfall SE corner.

The pastoral zone receives on average, about 350 to 550 mm rain per year but often experiences periods of extended drought.

The SE zone registers a higher rainfall and receives rain in most years. The rainfall varies from 750mm in the east of the region falling to 380mm towards the western areas. Periods of dry weather are also a feature of this zone. Most sheep graze native pastures. The holdings in the pastoral zone are large and sheep are stocked at low stocking rates.

In the SE zone holdings are somewhat smaller and stock are grazed more intensively. Some improved pastures and crops are sown and stock are turned onto crop stubble.

Barbers pole (Haemonchus contortus) is by far the most common and pathogenic worm found in Queensland flocks. Black scour worm (Trichostrongylus colubriformis) is also common but not to the same extent as barbers pole worm. Nodule worm (Oesophagostomum columbianum) can be a problem is some seasons.

Liver fluke (Fasciola hepatica) can be present in wet areas in the south east of the state.

Brown stomach worm (Ostertagia sp) may be present, but rarely in sufficient numbers to be of concern.

Tapeworm (Monezia sp) is common but does not cause any problems and should be ignored. There are no other worms of significance.

Also see:

• Principles of worm management in Queensland
• Drench resistance in Queensland

 Principles of worm management in Queensland

Worms thrive in the higher rainfall districts of the south east zone where stocking rates are high. The incidence of disease in this region requires constant intervention to control stock losses. In the pastoral zone however, worms are only a seasonal problem.

For sheep pastured in the higher rainfall areas east of the line from Mitchell to Dirranbandi and south from Roma to the border, the Department of Primary Industries and Fisheries, Queensland, conducts an integrated worm control program called Wormbuster.

The program strongly recommends monitoring worm infestations using worm egg counts so that drenches are given at the right time and drench resistance tests are conducted every two to three years.

Advice on non-chemical worm control methods such as pasture rotation and selecting sheep for increased resistance to worms is provided to support drenching recommendations.

A program of monitoring worm populations is recommended for producers in the drier areas west of the line.

Regular monitoring identifies rising worm populations and allows early intervention before production losses occur. Monitoring can also avert the outbreaks of clinical disease that occur after periods of prolonged rainfall.

The Wormbuster program runs a laboratory that provides worm egg counting (Early Bird Wormcheck) and drench resistance-testing services.

The laboratory also provides a monthly 'Wormbuster laboratory report', a two page report. It features data taken from the results of Early Bird Wormcheck tests submitted to the Wormbuster laboratory at Yeerongpilly, Brisbane in the previous month, as well as the latest worm management news relevant to Queensland.

The report is distributed each month via email. Request the report by sending an email to Arthur LeFeuvre.

Other relevant information can be found on the Wormbuster website or by calling the DPI Call Centre on 13 25 23 for the cost of a local call within Queensland to contact a sheep and wool officer.

 Drench resistance in Queensland

Widespread drench resistance in the high rainfall zones has forced producers to better use the few drenches still available for worm control and to pursue non-chemical alternatives.

A drench resistance survey conducted by the Department of Primary Industries and Fisheries, Queensland, in the Wormbuster target area in 1998 showed drench resistance to be a serious problem (Table 1).

Testing by the Wormbuster laboratory indicates that resistance has increased significantly since 1998, particularly to the ML and Closantel groups.

Producers in the south east sheep districts should conduct resistance tests on all drenches every two to three years.

Table 1. The number and proportion of flocks in which anthelmintic resistance was detected in a survey conducted in the south east sheep raising districts of Queensland, April to June 1998.

Other relevant information can be found on the Wormbuster website or by calling the DPI Call Centre on 13 25 23 for the cost of a local call within Queensland to contact a sheep and wool officer.