Internal parasites can be a serious problem for Australian livestock producers. Worms and liver fluke cause economic pain due to production losses and treatment costs. Not to mention the huge impact they have on animal welfare.
Thankfully, a well-planned integrated parasite management program using targeted drenching, parasite monitoring schedules, and non-chemical strategies, gives you the upper hand in the battle to keep your livestock fit and healthy.
Problem parasites for sheep and cattle
In sheep, an infestation of barber’s pole worms can see animals deteriorate in a matter of weeks. Black scour worms and small brown stomach worms can also pose serious threats to animal health.
For cattle in northern Australia, internal parasites to worry about include barber’s pole worms, nodular worms and small intestinal worms. In the south, the biggest problem is small brown stomach worms.
Liver fluke, carried by the liver fluke snail, primarily affects livestock in south-eastern Australia. In chronic cases, livestock lose condition and develop swelling of tissues underneath the jaw, otherwise known as “bottle jaw”.
Symptoms of a worm or fluke infection:
- Lower than expected growth rates
- Scouring and weight loss
- Pale membranes around the eyes
- Pale gums
- Bottle jaw
How do you test livestock for worms?
Faecal worm egg counts (WECs) are done on dung samples submitted to a laboratory in a WormTest collection kit. A fluke egg test can also be requested, though eggs only appear in the faeces of the host 8-10 weeks after infection, and an antibody test (ELISA) using blood samples may be more effective.
WECs are vital for effective parasite control. AgriWebb’s Operational Planner can recommend the optimal time to conduct a WEC, based on your production system and location.
Benefits of an faecal worm egg count (WEC) test include:
- A more accurate measure of worm burdens than visual assessment
- An early warning of burdens that could become a problem
- Prevention of unnecessary treatments
- Combined with worm-typing, it leads to better treatment choices
- It can be redone after a treatment, to test drench effectiveness
Tips for drenching sheep
- Quarantine introduced livestock and treat with a quarantine drench
- Only drench when necessary, guided by worm egg counts
- Calibrate drench guns to ensure an accurate dose is delivered
- Calculate the dose based on the heaviest animals in the mob
- If there is a broad weight range, split mobs into light and heavy groups, and drench accordingly
- Never use a broad spectrum drench when a narrow spectrum is adequate
- Conduct drench trials every 2-3 years to find out which combinations of drenches remain effective, to determine rotation options
Considerations for drenching cattle
While sheep are typically treated with an oral drench, cattle can be treated with an oral drench, injection or a pour-on drench. It is important to note that worm egg counts don’t reflect worm burdens in cattle as well as they do with sheep. You can still have significant production losses due to worms despite a low worm egg count. If in doubt, try a “diagnostic treatment”. That is, identify and treat a proportion of the affected mob and assess any responses to the treatment.
The importance of integrated parasite management
Drench resistance is widespread in all sheep growing regions in southern Australia, and has been reported, though less commonly, in cattle. Integrated parasite management calls on a range of techniques to control worms so that drench can be used less.Integrated parasite management strategies include:
- Requesting an animal health statement when purchasing livestock
- Monitoring the worm status of the mob regularly, particularly high-risk animals
- Improving in-flock resilience by culling susceptible sheep and using sires with favourable breeding values
- Managing exposure to worms by providing low-risk pastures, achieved through practices such as rotational grazing, grazing with alternate species, and spelling pastures
- Fencing off areas where liver fluke snails are known to be abundant
- Maintaining body condition targets with balanced nutrition, through good quality pastures, mineral licks where deficiencies have been identified, and supplementary feeding if required
- Using biological controls such as dung beetles to reduce pasture contamination
In some regenerative agriculture systems, these strategies may be used to replace drenching altogether. When you are using drench, it’s imperative that you keep reliable records of the treatments used on-farm to allow ongoing management of parasites. This will also ensure that you are prepared for farm audits.
With AgriWebb, treatments can be recorded in the field as you go, with farm inventory automatically updated at the same time. To see how the software can help with your operation, sign up for a free trial today.