Subtropical Rangelands
While you may be researching or planning a program for a specific parasite that is a problem for your property, it pays to be aware of what other parasite risks may be approaching and make an integrated plan.
Programs for the key parasites, ticks, buffalo fly, lice, worms and fluke can be opened below. The recommendations are generic and therefore need to be customised to the needs of individual producers and delivered by those with knowledge in the field.
Be aware that chemical resistance can develop in both targeted and non-targeted parasites.
Use of chemicals to control one type of parasite can also unintentionally select for resistance in a different group of parasites. It is important to read the label to determine which parasites will be controlled. Resistance is a significant issue in ticks, buffalo flies and cattle worms. When choosing a chemical to control one of these parasites, consider the possible side effects of increasing selection for resistance to the others.
Strategies for delaying the emergence of chemical resistance include:
- Where possible include non-chemical control strategies to reduce reliance on chemical treatments.
- Avoid frequent use of the same chemical or chemicals within the same chemical group.
- Don’t under-dose products as this allows the more tolerant pests in a population to survive. Common causes of under-dosing include under-estimating the weight of animals being treated, poor application technique, and mis-calibrated application equipment.
- Use chemicals according to the product label.
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Buffalo flies may become a problem in some areas during very wet seasons.
- Treat if buffalo flies are above industry threshold numbers.
Beef animals. 200 flies
Dairy animals. 30 flies
Lice on cattle are generally not an economic problem. Only treat when heavily infested as indicated by rubbing on fences or structures.
Seasonal trends
Louse numbers increase
late autumn early spring
Optimal timing of treatment if needed (heavy infestation)
late autumn
Louse numbers increase from late autumn through to early spring and then decline with increasing temperatures in spring and summer. Heavy infestations are usually seen in cattle in poor body condition. In most cases the lice are a consequence, and not the cause, of poor nutritional conditions. Where lice are an on-going problem a single treatment in late autumn will usually provide effective control.
Cattle tick is not a problem in this region
- Climate largely unsuitable for ticks of economic importance to cattle so routine tick treatment programs are not required.
- Any cattle tick infestations found in the tick free area must be reported to the relevant State authority.
Routine worm treatment programs not required.
- A WEC at weaning is recommended.
Highest WECs
Autumn
Other worms
Sporadic outbreaks in very wet years or due to crowding of young stock.
Barber’s pole worm (Haemonchus placei)
Nodule worm (Oesophagostomum radiatum)
Small intestinal worms (Cooperia species)
