Along with grazing management, roundworm control is achieved through the strategic use of effective anthelmintics or drenches. Combination drenches containing a macrocyclic lactone (ML) (e.g. abamectin, eprinomectin) and levamisole are recommended for use in cattle under 15 months of age2, as the ML is very effective against Ostertagia roundworms while levamisole is very effective against Cooperia spp resistant to MLs.
Cooperia is the most common parasite of young cattle with widespread high-level resistance to MLs recorded throughout New Zealand2.
In addition, the use of combination anthelmintics are thought to slow the development of resistance to the actives in the combination.
While oral drenching is considered the most effective way to deliver drenches in terms of parasite control, the practicalities of dosing animals over 200kg means that pour on products have gained widespread acceptance amongst farmers, being quick, safe and simple to apply correctly.
One pour on product which fits these requirements is Outlaw Pour On.
Outlaw Pour On contains 10g/L abamectin and 200g/L levamisole, and has registered claims against all important roundworm parasites, including ML resistant strains, lungworm and sucking lice in cattle.
Treating yearlings (R2s) in early Spring can remove inhibited Ostertagia to maximise weight gain which will not only maximise fertility but enable the calving weight and BCS score to be reached well before calving.
Outlaw Pour On has a dose rate of 1mL/20kg. Withholding periods are 42 days for both milk and meat, and animals under 100kg must not be treated.
Ask your animal health advisor for recommended parasite management practices for your area to reduce the development of resistance. It is advisable that a resistance test be conducted regularly when using any parasite treatment.
1 “Heifer management: The impact of undergrown heifers”. L McNaughton, T Brownlie, S McDougall. Proceedings of The Society of Dairy Cattle Veterinarians of the NZVA Annual Conference, 2014.
2 Wormwise Technical Manual 2019. Outlaw is registered under the ACVM Act 1997 No 010375. EM-NZ-23-0099.