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Cattle ticks – autumn clean up


Count your eggs before they hatch!

Recent wet season rains over the north of Australia provide ideal conditions for development and survival of cattle ticks and their larvae. This means that springtime could pose a serious risk to cattle unless producers clean up tick numbers this autumn.  

Cattle vs Ticks

Ticks suck blood, slow growth and production, transmit tick fever, cause hide damage and lead to the deaths of cattle right across northern Australia. But we know their weak points and have a strategy to beat them.

To maximise return from the effort you put into tick control, preparation is key. The main factors are:

  • Taking advantage of the tick life cycle and biology
  • Strategic treatments in spring to stop tick numbers exploding
  • Tactical treatments in summer and autumn to stop animal health risks and limit pasture contamination.

 

Biology and life cycle

Australian cattle ticks (Rhipicephalus australis) spend their lives either on the cattle (about 3 weeks) or on the paddock (minimum 3 weeks). They start off as eggs, which develop on the ground and hatch. The larvae then crawl up the grass and wait for a beast to jump onto.

Once aboard, they feed, moult, feed, moult again then turn their minds to mating. Male and female ticks become intimate, and the female ticks fall pregnant. This is the signal for her to begin feeding, not just for herself but for her 3,000 babies. The ticks suck more blood over the next few days than over their entire lives to date.

The blood they suck is quickly converted into thousands of ripe tick eggs. This results in the big, round female ticks that we see clinging like fat peas to the skin of cattle. Each tick that engorges takes away 0.6 to 0.9g of growth from the beast. Once they’ve engorged, the female ticks drop off onto the ground and start to lay the eggs.


 

Autumn clean-up

Cattle ticks can be seen at any time of the year with the numbers found on cattle increasing rapidly from summer to autumn in NSW and southern QLD, and during the wet season and early dry season in NT, WA and north of Queensland. Larvae laid in pasture to survive the winter season are responsible for the rise in tick numbers in the following spring.

This makes now the best time to monitor cattle tick numbers to control ticks using a tactical treatment. 

Larvae (hatched eggs) in the environment are sensitive to climatic conditions but can survive up to two months in summer and as long as seven months in winter. Larvae need to infect a new host or they will die. Rotational grazing, making hay or pasture spelling also give ticks time to die out before a new mob of cattle arrive for them to infest.

 

Impact of treatment

Smashing numbers on cattle now will decrease the risk in springtime. Treating cattle, then moving them to a fresh paddock will minimise the ticks that could potentially seed the pastures with larvae. Check local advisers or do a resistance test to know resistance status of different products.

 Table 1: Types of tick treatments to use in autumn to stop tick larvae contamination on pastures over winter

Type of treatment

Chemicals

Effective period

Treatment interval

Comments

Short-acting

dips, sprays, pour-ons

Amitrazâ

Organophosphatesâ

Synthetic pyrethroidsâ

Pour on mectins

18-21 days

21 days

Check product label for meat and milk withholding periods (WHP), export slaughter interval (ESI) and re-treatment intervals

Medium-acting

Injectable mectins

e.g. doramectin injectable

28-30 days

28 days

 

 

 

 


â resistance to these chemicals is widespread in Queensland, (but not in WA or NT)- consult local authorities for regional resistance status and submit ticks for resistance testing to know best chemical choice for your herd

Long-acting treatments such as moxidectin LA injection are best used in springtime to treat successive waves of ticks (protection period against tick eggs laid is 65 days), rather than for tactical treatment in autumn.

 

Strategic control

To make sure ticks do not cause any damage to your herd, follow these steps:

  1. Vaccinate all calves with tick fever vaccine once at 3 – 9 months old.
  2. Submit ticks to the Queensland Biosecurity for tick resistance testing on a regular (semi-annual) basis.
  3. See if Bos indicus or composite genetics will improve your herd’s productivity.
  4. Examine cattle regularly and treat before numbers get above your threshold.
  5. Follow your state government regulations about moving cattle across tick lines and borders.
  6. For more information on cattle tick management check out TickBoss or see MLA’s Tick Information Page.

Timing is critical. Act now to make sure that you count your ticks before they hatch!