Worm infestations: Don’t guess, do a test
Many producers believe they can pick when their cattle are affected by worms. This may be so, but there are many other circumstances that cause animals to look ‘wormy’. Poor nutrition is the most common mis-diagnosis of animals being ‘wormy’.
Contrarily, it is worthwhile remembering, animals do not have to be showing outward signs of a worm infestation before production losses occur.
All the more reason to conduct a worm egg count before taking action.
Worm egg counts
The most effective and practical method of determining worm burdens is to measure the worm egg level in the dung.
Results are expressed as eggs per gram of dung (epg).
If egg counts are below 200epg it is unlikely that worms are causing a problem. If egg counts are >200epg it is important to determine what species of worms are present. This is because different worms cause problems at different infestation levels.
When and who to test
It is recommended that calves be checked at, or within one month, of weaning and again about a month after the season breaks. The follow-up test is important to ensure worm burdens remain under control.
Worms are generally not considered to be a great problem in cattle over 20 months of age on extensively grazed beef properties. However on some properties in wet years where permanent pastures are continually grazed, stock under 20 months of age may be at risk.
Do you need to drench?
The decision to drench should be based on a worm egg count result. Results from testing over the last 10 years show that 70% of submissions carry very low worm egg counts and require no treatment.
If you do drench, be sure to conduct a post-drench faecal worm egg test 7 days later. If the drench has been effective, results should come back with zero worm egg count.
Contact your local vet to organise laboratory testing.
Written by Maxine Lyndal-Murphy, formerly Queensland Government.