Future-proof parasite management

Effective parasite management is essential to achieving strong growth in young cattle, but to be sustainable, strategic management practices alongside smart drench use are key to long-term success.

Early growth matters

Achieving target liveweights in replacement heifers is essential for lifetime performance and longevity in the milking herd. With internal parasites being a leading contributor to poor growth rates in calves, an effective but sustainable parasite management programme is required.
 

Sustainable parasite management

With drench resistance in cattle a very real and present concern, relying solely on drench for parasite management is not a sustainable option. Calves that are exposed to minimal parasite larval challenge will not only grow faster but also require less drench inputs, helping to minimise resistance pressure.
 

Low larval challenge feed options

• Forage crops or new pasture
• Areas previously grazed by sheep or older cattle
• Maintaining higher grazing residuals and avoiding the lower 2-3 cm, where larval contamination is greatest
• Silage or hay paddocks When drenching is required, ensure refugia practices are in place. Refugia help to dilute the resistant parasite population and slow the development of resistance.

Examples

• Ensuring a minimum 28-day drench interval
• Cross-grazing with older cattle 27  
• Leaving a portion of well-growing calves un-drenched using targeted selective treatments (TSTs)
• Not shifting to clean pasture immediately post-drench

Drench decisions

When choosing a drench for calves, there are three key factors to consider.

• Calves under 100kg are susceptible to abamectin toxicity, so drench combinations containing it should be avoided in this weight group
• For cattle under 12 months, levamisole is advised to target Cooperia
• Oral drench is best If drenching calves under 100kg, consider Active + Merge, a 1mL/10kg oral drench containing oxfendazole and levamisole, which is a safe and effective choice for this weight range.

Once calves are over 100kg, a triple-combination oral drench such as Active + Treble is recommended.

Both these drenches are mineralised with selenium and cobalt for additional mineral supplementation. When it’s not safe or feasible to use an oral drench in calves, choose either a pour-on or injectable combination drench that contains levamisole.
 

Smart drenching

• Weigh a sample of the mob and drench to the heaviest to ensure no calf is underdosed
• Where there is a large weight range, draft into multiple lines to avoid potential toxic overdosing
• Calibrate and check drench guns to ensure correct dosage
• Agitate drench in drum before decanting
• Incorporate refugia
• Monitor drench efficacy with 10-day post-drench faecal egg count (FEC)

Putting it into practice

Maximise calf growth this summer by providing low larval challenge feed where possible and minimise unnecessary drench use by using FECs to guide drenching decisions.

When drench is required, choose a safe and effective option and use it wisely, monitor efficacy through 10-day post-drench checks and incorporate refugia to support sustainable parasite control.

Talk to your local vet and Farm Source team about calf parasite management, drench options and how to use them effectively this summer.
 

Article supplied by Nexan