Bio-acoustic repellers are for the birds
With birds flocking to dairy farms for winter feed sources, Rutgers University researchers found bio-acoustic repellers1 can be effective in protecting feed supplies and herd health. Trial results, released by Rutgers’ Agricultural Experiment Station, found the repellers were effective at driving birds out and keeping them away from barns, feed bunks and silage.
The study was conducted last winter on two New Jersey dairies: Fox Dairy a 220-cow operation in Pilesgrove; and Doak Dairy, a 150-cow dairy in Mannington. Both had consistently experienced moderate-to-severe bird infestations for several years.
When the study started, both dairies were already experiencing severe bird infestations. During winter months starlings, sparrows, cowbirds and pigeons would invade the barns by the hundreds and thousands, perching in the rafters and leave droppings along the backs of cows, coating equipment and contaminating feed. The dairy owners had each tried several means to keep the birds out, including hazing, netting and poisoning programs through USDA’s Animal and Plant Health Inspection Service (APHIS). Results were temporary, and the birds eventually returned.
“Our silage is stored right near our barn and it was a huge magnet for the birds,” said Joe Doak, owner of Doak Dairy. “We had birds everywhere. You couldn’t walk through the yard or the barns because of them.”
Researchers installed bio-acoustic units in the freestall barns at both dairies. The units play digital recordings of actual bird distress calls – combined with the sounds of their natural predators – to stimulate the bird’s survival instincts, causing them to flee.
Bird distress calls have been used worldwide for decades to protect vineyards and other soft fruits. The units target the specific species of bird causing problems. A unique microprocessor randomizes the distress sounds and predator calls, preventing birds from adapting.
“The effects were immediate, keeping the birds at bay and scaring them from their roost trees nearby,” Doak said. “We went from having a barnyard full of birds to having none at all. Within days every bird had left the barns.”
Doak eventually purchased and installed additional units in his freestall barn and milking parlor to protect his robotic milker and silage.
“With the money saved from the feed lost, the system paid for itself in a couple of weeks,” he said. A single unit, effective for controlling bird populations per 100 cows, is about $240.
As long as the unit was turned on, the birds stayed away and never came back.” said Ted Fox, owner of Fox Dairy. “Placing this system on my operation was simple, cost efficient and effective beyond my expectations.”
Researchers estimated a large flock of birds can consume more than a ton of feed per week, selectively eating the expensive protein and grain. In addition to affecting the ration nutrient content – reducing milk production and impacting overall herd health – the birds can also spread diseases through their droppings, including E. coli, meningitis, several strains of encephalitis, salmonella and a host of fungal-related respiratory disorders.
APHIS and the Centers for Disease Control have identified 65 diseases transmittable to humans or domestic animals as a result of contact with bird droppings.
1/ Bio-acoustic bird repeller units were provided by Bird Gard.