Beetle-Friendly Parasite Policy Cuts Dairy Farmer Costs by £8 Per Cow

An eco-conscious dairy farmer has successfully reduced treatments for youngstock by 70%, implementing a groundbreaking, multi-faceted strategy for managing parasites, including the use of dung beetles.

Bruce Thompson, who operates Camcloon Dairy located near Portlaoise in County Laois, has saved over £2,500 on treatments for his R1 and R2 heifers and milking cows by harnessing natural methods to minimize the use of anthelmintics and pyrethroid applications.

“I believe that while wormers play a vital role, responsible use is crucial,” Bruce states. “I want to ensure they remain effective by avoiding overuse, which leads to resistance.”

“Additionally, anthelmintics have a broad-spectrum effect that can inadvertently harm beneficial insect populations.”

See also: How regenerative farming can boost livestock health

Bruce Thompson © Michael Priestley

Innovative Techniques

A 2020 Nuffield scholarship inspired significant changes on the farm. Bruce traveled to Tasmania, Australia, and various regions in the UK and Ireland to explore sustainable wormer practices.

He has incorporated an array of methodologies acquired through his studies and travels, leading to a decreased need for worm and fly treatments:

Selective Targeted Treatments

Rather than treating an entire group of R1s for worms, Bruce selectively treats those showing low growth rates or loose stools. This approach typically allows R2s and milking cows to go without wormers, having developed immunity over time.

This reduction in anthelmintic use slows the emergence of resistance and protects beneficial insect populations like dung beetles.

Treating only affected animals helps to clean infested pastures by interrupting the parasite life cycle, which can typically take three weeks.

Faecal Egg Counts

Bruce uses his microscope to conduct faecal egg counts (FECs) during spring and summer on his R1s, with a treatment trigger set at 250 eggs per gram.

Dung Beetles

Fresh cow pats provide a habitat for flies, worms, and flukes. Dung beetles consume the moisture in the pat and utilize microbes for nourishment.

They also bury dung balls deep into the soil, helping to eliminate the environment in which worm eggs can survive and thus breaking the parasite life cycle.

Bruce is actively collecting dung beetles and placing them in specific habitats for breeding purposes.

Clean Grazing Practices

Bruce assesses pasture parasite risk using a traffic light system:

• Green (low risk): Fields that have recently reverted from arable to livestock, have been spelled, or recently grazed by treated animals.
• Amber (medium risk): Pastures contaminated by shedding calves, grazed recently by cows or R2s to minimize parasites.
• Red (high risk): Areas grazed by R1 calves that showed significant egg shedding.

Spelling Pasture

This method turns an infected “red” pasture into a clean one through:

• Silaging: Cutting grass for silage helps physically remove parasites and exposes larvae to harmful sunlight and air, effectively killing them through the ensilement process.
• Cow Hoovering: Cows and R2s graze the field multiple times before closing it for winter, effectively ingesting and eliminating parasites in their rumens. Short grazing sessions further limit fresh dung deposits.

Eucalyptus Oil

This oil is utilized in two primary applications:

• R2 Pour-On: Administered to R2 heifers (20–30ml) in summer to combat fly issues—applied twice in 2023, though not needed this summer.
• Teat Spray: Mixed with polysorbate and water in a 1% solution for use in teat spray applications—also not required this summer.

Stockholm Tar

This sticky substance is applied to teats with a paintbrush to deter flies, but has not been necessary this year.

Calf Care Protocol

As the most vulnerable part of the herd, calves are prioritized in Bruce’s management system, designed to enhance their parasite immunity while optimizing labor efficiency.

Calving begins on February 1, with newborns receiving colostrum at 8.5% of their birth weight (average of 25kg) followed by transition milk from their dams.

Calves are placed in a wheelbarrow for tasks like genotyping, registration, and treating navels with iodine, followed by weight estimation using a wooden frame scale.

Initially fed individually for one to three days, they are later grouped into batches of 20. Weather permitting, they are then moved to green-risk-level pastures, with up to 60 heifer calves sharing one milk feeder.

Calves strip graze using a two-to-three-day rotation and receive pelleted calf feed through a restricted feeder.

The milk replacer is prepared via a gravity-fed system from a heated water source at 39C.

Initially, calves are provided with coarser forage at 3,500kg dry matter/ha or more to promote rumen development, while restricting rich spring grass to avoid scours.

Calves are weighed every four weeks, and FECs are performed when parasite challenges are suspected.

Daily weight gains must average 0.6 kg to meet a target bulling weight of 300kg by May 1, ultimately growing into 480-500kg mature cows.

Weaning occurs when calves reach 2.7 times their birth weight. Once reaching 160kg or more by August, they are transitioned to amber pasture to enhance their tolerance.

During their first winter, calves stay in a slatted shed from mid-November until turnout in March or April. Animals are grouped by weight, ensuring smaller ones receive added concentrate in their silage diet of 2kg/day.

By the time they are turned out as R2s, these animals have developed immunity and can contribute to the hoovering process in pasture spelling.

Cost Savings

Bruce reports as few as one treatment for lungworm and 0.7 worm treatments per R1, a dramatic reduction from an average of four treatments per calf in 2020.

This strategy is saving time, resources, and money while also mitigating the rise of parasite resistance.