PRISYM model trial

We are exploring the use of a farm systems optimisation model to improve parasite management in sheep and cattle while reducing drench resistance. If successful, this model could provide farmers with a strategic tool to evaluate different management strategies.

image of map showing Modelling drench resistance impacts

Background

Beef + Lamb New Zealand is investigating whether the PRISYM model can help us design better farm systems to tackle internal parasites in sheep and beef cattle, while also reducing the risk of drench resistance. This initiative aims to provide farmers with a strategic tool to enhance parasite management on their farms. We’ll analyse how the PRISYM model can simulate the effects of drench resistance within farm systems. If successful, this model could offer farmers a strategic tool for evaluating different parasite management strategies.

Focus areas

  1. Base Farm Model:
    • Assume no existing parasite resistance and apply best practices like refugia.
    • Plan for 10 years to account for pasture growth variability.
    • Include the cost of testing drench efficacy.
  2. Impact of drench resistance:
    • Assess how resistance affects:
      • Growth rates of finishing and replacement animals.
      • Fecundity (ewes) and fertility (ewes & cows).
      • Death rates of adults, replacements, and finishing animals.
  3. Forage crops for parasite management:
    • Evaluate the use of different crops to manage parasites:
      • Annual Crops: Summer turnips, annual ryegrass, etc.
      • 3-Year Crops: Chicory.
      • Long-Term Pasture: Lucerne.
    • Assess how these crops impact animal growth rates for finishing animals and replacements.

Benefits to farmers

  • Enhanced management tools: Gain access to advanced modelling tools to better understand and manage parasite challenges on your farm.
  • Strategic planning: Use insights from the model to make informed decisions about parasite management and drench resistance strategies.
  • Optimised forage use: Discover how different forage crops can help manage parasites and potentially improve animal growth rates.
  • Improved productivity: Apply best practices to reduce the impact of anthelmintic resistance and enhance overall farm productivity.

B+LNZ Project Lead

Cara Brosnahan, Principal Scientist – Animal Health Research.

Farmer involvement

Six farms (North and South Island).

Provider

John Rendel, Agrisystems and Analytics.

Expected end date

December 2024.