A 2012 study highlighted the importance of fully effective anthelmintics in young cattle systems. In brief, R1 Friesian bulls treated with a fully effective anthelmintic gained 100g a day more weight than those treated with a less-effective anthelmintic, resulting in a 6kg difference after 60 days2. Heifers reaching target liveweights will produce 8.5kg MS more in their first lactation than if they are 10% below target2.
Along with grazing management, roundworm control is achieved through the strategic use of effective anthelmintics or drenches. Combination drenches containing a macrocyclic lactone or 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 effective against Cooperia. Cooperia is the most common parasite of young cattle, with widespread high-level resistance to MLs recorded throughout NZ3.
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 pour-on products have gained widespread acceptance amongst farmers; they are quick, safe and simple to apply correctly.
Outlaw Pour On, for example, contains 10 g/L abamectin and 200 g/L levamisole, and has registered claims against all important roundworm parasites, including ML-resistant strains, lungworm and sucking lice in cattle. It has a dose rate of 1 mL/20kg. Withholding periods are milk 42 days, meat 42 days.
Treating yearlings (R2s) in early spring can remove inhibited Ostertagia, to maximise weight gain. This will maximise fertility and enable the weight and BCS score to be reached well before calving.
Ask your animal health advisor for recommended parasite management practices to reduce the development of resistance. It is worth doing regular resistance tests when using any parasite treatment.
For more further information, contact your Farm Source TSR or visit the Farm Source website.
__________________________________________________________________________________________________
1 Leigh, J. et al. (2013). The effect of ML-resistant Cooperia in healthy cattle. Proceedings of the Society of Sheep and Beef Cattle Veterinarians of the NZVA, Proceeding of a Combined NZVA Conference of the Society of Sheep and Beef Cattle Veterinarians(Jan).
2 McNaughton, L., Brownlie, T. & McDougall, S. (2014). Heifer management: The impact of undergrown heifers. Proceedings of The Society of Dairy Cattle Veterinarians of the NZVA Annual Conference.
3 Wormwise Technical Manual 2019.
Outlaw Pour On is registered under the ACVM Act 1997 No 010375.
Article supplied by Elanco.