Managing parasitic worms in livestock is a tricky business for people on small farms. There are many variables to understand and manage including animal factors (breed, age, sex, pregnancy status and nutrition), grazing options and climactic conditions. This workshop was an opportunity for participants to learn about management tools that reduce the need for drenching and maximise the efficiency of drenches when they are used.
Dr Jane Morrison from Coopers Animal Health and Dr Alexandra Stephens from South East Local Land Services spent the day with our participants guiding them through the theory of worms and the practical aspects of worm management. Our hosts Suzie and Catherine showed participants how to do DIY faecal egg counts using a microscope.
The following points were the highlights of the workshop for Tracey, one of the participants.
1. Learning about the life cycle of the different worms in sheep and cattle was really important. I now understand how the worm life cycle can help inform strategic grazing decisions and the class of animal that you might graze on a particular paddock. I found out that temperature and rainfall impact on the survival of worm eggs and larvae on the pasture. There are two main life cycles of worms direct and indirect. Direct life cycles involve only one host, for example round worms and indirect life cycles involve two different types of hosts.
Round worm life cycle
Liver fluke life cycle – an example of an indirect worm life cycle.
2. Using faecal egg count tests can help inform decision making about drenching livestock and potentially save me time and money. The demonstration of how faecal egg counting is done helped me understand that using worm testing is a good management tool that can enable targeted use of drenches when needed.
Drench decision guide for sheep
3. Overall, the main benefit of the workshop for me is that I now realise how much detail there is in controlling worms in animals and that improving my knowledge about worms and their management can make a big difference to their health.
Five key components of a worm management strategy
Grazing management is the most important factor in controlling worms. Grazing management can include spelling paddocks and choosing the best clean paddocks for the classes of stock that have the highest nutritional demands and susceptibility to worms (weaners and pregnant or lactating ewes). Control worms without drench by using good grazing management including ‘smart grazing’, cross grazing with other species, rotational grazing and the use of fodder crops.
Grazing management and worms
Breed and feed for worm resistance. Older animals in good condition have higher immunity to worms than young or poorer animals. Adult cattle and sheep are good at developing worm immunity, except when they are lambing/calving and lactating. Aim for a condition score of 2.5 or above for more resilient animals with stronger immunity. Rams and breeding ewes can be selected for worm resistance – some breeds may have higher immunity to worms including Corriedale and Border Leicester sheep.
Use strategic drenching and good drenching principles. Dose correctly to the heaviest animals, calibrate the drench gun, use faecal egg counting to check drench efficiency and choose combination drenches with 2 plus additives. Use long acting drenches judiciously as they can accelerate resistance in worms. Always use a quarantine drench when you purchase new stock even if you have been told that the animals have been drenched. There are special drench combinations that should be used for quarantine drenching. Drench lambs/calves at weaning as they are highly susceptible to worms and are usually being weaned during high worm risk weather. Seek further advice form a vet if you need help.
Tactical drenching – these are drenches that are used when a faecal egg count test shows a high result or the animals show clinical signs of worm infestation.
The difference between tactical and strategic drenches – WormBoss
Manage worm resistance by informing yourself about the causes and what you can do to help prevent it. Get advice about interpreting faecal egg count tests and managing worms in livestock. Drenching may not be necessary if egg counts are low.
Managing drench resistance
You can contact your Local Land Services office for guidance on managing worms in livestock. Kits for faecal egg count tests are available free from Local Land Services offices and many rural suppliers.
The WormBoss website provides a comprehensive toolkit for managing worms.
More information and links
Worm Control in Cattle – the Basics – NSW DPI Fact Sheet
Cattle parasite atlas – Meat and Livestock Australia – a comprehensive guide to managing cattle parasites in the different regions of Australia.
South East Local Land Services Animal Health Update – this update includes information on Barbers Pole Worm and Bioworma.
Worm Boss Canberra Region Drench Program
Worm Control in Horses – it’s all changed – Dr Petrea Wait (scroll down to the Animal Health Update February 2018)
DIY worm egg counting
Worm test for livestock and guide to egg counts
Liver Fluke guide from WormBoss