Ticks
Cattle tick is not routinely a problem in this region but outbreaks can and do happen, most often following cattle introductions from other tick-endemic areas.
Problem ticks
- Paralysis tick and bush tick occur in this region peaking in spring and summer.
- Routine control measures for bush tick are generally not warranted.
- Young calves are particularly susceptible to paralysis tick toxin so if your property is in a paralysis tick area, consider treatment before paralysis ticks can inject a lethal dose of toxin.
Flies
Buffalo flies
- Treat if buffalo flies are above threshold numbers before Christmas, or after ear tags have expired (apply an OP spray or a pour-on from a different chemical group to that of tags). Industry threshold numbers are:
Beef animals. 200 flies
Dairy animals. 30 flies
- Apply insecticidal tags when flies are above economic thresholds in January.
- Remove tags when they expire (Check label; 16 weeks for most tags) to avoid selecting for resistance.
- Use ear tags from different chemical groups in successive years (OP, SP, ML).
- Consider using buffalo fly traps or backrubbers.
Lice
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.
Worms
Highest WECs
Winter
Significant worms
Barber’s pole worm (Haemonchus placei)
Small brown stomach worm (Ostertagia ostertagi)
Small intestinal worms (Cooperia species)
Liver fluke
Other worms
Nodule worm (Oesophagostomum radiatum)
Stomach hair worm (Trichostrongylus axei)
Stomach fluke (Calicophoron calicophorum)
Calendar for worm and fluke control
| KEY |
| √ |
Strategic worm treatment given each year |
| (√) |
Not a routine treatment. Indicators for treatment include scouring, sudden loss of condition and a condition score of 2 or less, especially if feed availability is less than 1,000kg DM/ha. Treatment will be more effective if combined with a change to ‘low-risk’ pastures, especially for young stock. |
| Fi |
Both adult and immature fluke present – select a drench that kills all fluke stages |
| (Fi) |
Adult and immature fluke present. This drench may not be needed on properties with a low fluke risk. |
| F |
Only adult fluke present. Use a drench other than triclabendazole to help slow the development of resistance. |
Table 1. Calendar for worm and fluke control in spring calving herds.
| Age group |
Mar-May |
Jul |
Sep |
Dec |
| Weaners |
√ Weaning |
√ |
(√) |
√ |
| Yearlings/First calvers |
√ |
(√) Pre-calving |
|
(√) |
| 2nd calvers |
|
(√) Pre-calving |
|
|
| Adult cows |
Adult cows usually develop a strong immunity to roundworms so mob-scale drenching should not be required – individual cows showing reduced weight gains or signs of internal parasitism (diarrhoea, low body condition score, ill-thrift or high WEC) should be treated. |
| Bulls |
|
|
|
√ Pre-joining |
| Liver Fluke control |
| All weaned cattle |
Fi |
|
F |
(Fi) |
| Stomach fluke control |
| A single treatment of all weaned cattle in Sep will usually control stomach fluke in ‘flukey’ areas e.g. swamps, inundated areas, river flood plains. However, in some cases an additional treatment may be required in Mar-May based on monitoring and veterinary advice. |
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