Ticks
Cattle tick is not usually a problem in this region
Problem ticks
- Bush tick rise in spring or with wet season, adults most numerous in spring and summer. Routine control measures for bush tick are generally not warranted.
Flies
Buffalo flies now commonly found during summer.
- Treat with a spray or pour-on if buffalo flies are above threshold numbers, of if cattle are showing significant ‘fly worry’. Industry threshold numbers are:
Beef animals. 200 flies
Dairy animals. 30 flies
- If the fly season is expected to last longer than 2 months consider using insecticidal tags if cost effective.
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
Autumn
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)
Calendars 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. |
| ML |
Macrocyclic lactone |
Table 1. Calendar for worm and fluke control in spring calving herds.
| Age group |
Jan-Feb |
Apr-May |
July-Aug |
Oct-Nov |
| Weaners |
|
√ Weaning |
√ |
√ |
| Yearlings |
(√) Required if Oct-Nov drench was not an ML |
(√) |
|
|
| 1st and 2nd calvers |
|
| 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 |
|
|
|
√ |
| Liver Fluke control |
| All weaned cattle |
(Fi) |
Fi |
F* (Aug) |
|
| *A single treatment of all weaned cattle in Aug will usually control stomach fluke where it is present |
Table 2. Calendar for worm and fluke control in autumn calving herds.
| Age group |
Dec-Feb |
Apr-May |
July-Aug |
Oct-Nov |
| Weaners/ yearlings |
√ |
√ |
√ |
(√) |
| 1st and 2nd calvers |
|
√ |
(√) |
|
| 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 |
√ |
| Liver Fluke control |
| All weaned cattle |
(Fi) |
Fi |
F* (Aug) |
|
| All weaned cattle |
(Fi) |
Fi |
F* (Aug) |
|
| *A single treatment of all weaned cattle in Aug-Sep will usually control stomach fluke where it is present |
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