Using real-time generated rate-of-gain to determine anthelmintic need in pastured Blue Faced Leicester Maryland lambs

View the project final report

Commodities

• Animals: sheep

Practices

• Animal Production: animal protection and health, parasite control

In Maryland the barberpole worm, Haemonchus contortus, is the most prominent health concern in
young lambs. Anthelmintics are available; however, worms are becoming resistant. The proportion
of animals receiving anthelmintics is the most important factor determining the rate of resistance
development. This grant proposal uses three objectives to study a practical on-farm approach to
responsibly treating affected animals while slowing the rate of resistance:

1) Compare the number of lambs treated using the rate-of-gain versus lambs versus a FAMACHA©
score. FAMACHA© may serve as a “gold standard”; however, rate-of-gain does not have training
requirements or physical handling, increasing the likelihood of adoption by producers.
2) Document producer timesavings by comparing rate-of-gain decision making with RFID tags
versus FAMACHA© examination. This technology is expected to increase adaptation of
rate-of-gain as a treatment determination factor for producers with larger flocks.
3) Test for parasites resistance to anthelmintics to compare resistance rates between the most and
least treated animals in a flock. We anticipate that animals that have not been treated will maintain
a higher percentage of worms susceptible to anthelmintics.

We will host a field day for a pre-existing group of commercial sheep and goat producers and rely
on our technical advisor for additional outreach. Participants would learn how rate-of-gain can be
calculated, and see in person, or by video how RFID technology can simplify the process.
Resistance rates should show producers the value of not treating all animals in their flocks.

Our proposed solution is using real-time generated rate-of-gain measurement to determine if anthelmintic treatment is necessary. Rate-of-gain is a performance measure that can be easily calculated requiring little additional equipment and training. For larger producers, use of Radio Frequency Identification Device (RFID), corresponding readers and software can be used for real-time decision-making (following an initial baseline weight). Overcoming training obstacles, reducing time inputs, and demonstrating efficacy may increase the number of producers who choose to selectively treat animals and slow anthelmintic resistance.

This research has three objectives. First, the study will compare the number of lambs treated using the rate-of-gain versus lambs that would be treated using a FAMACHA© score, a currently commonly used identifier. Second, the time to record FAMACHA© scores versus rate-of-gain decision-making will be recorded to demonstrate producer timesavings. Third, fecal samples from the co-located lambs will be pooled from animals needing treatment, and pooled from animals not requiring treatment, and tested for parasites resistance to anthelmintics to compare resistance rates.