Birds are drawn to livestock operations’ continuous supply of available fresh feed. They feed on forage bunkers, piles, and feedbunks, consuming the energy-dense components of the feedstuffs or ration, which leads to increased feed costs. Birds also increase disease risk by contaminating livestock feed.
    The most common invasive bird migrating to dairy farms in the winter is the European starling. Adult starlings are about 8.5 inches in length and weigh 3.2 ounces. Like most other birds, starlings consume about half their bodyweight in grain daily. It is not unusual for flocks numbering in the tens of thousands to migrate to a farm, leading to feed consumption well above 1,000 pounds per day.
    Starlings consume the high-dollar feed ingredients, such as grains and concentrates. Estimates of bird damage on commercial dairies in Wisconsin, New York and Pennsylvania suggest that starling damage resulted in $64,000 of feed loss annually per farm when the bird population reached 10,000 birds or more per day.
    The value of feeds consumed by birds is only part of the economic losses incurred on a dairy. Dairy nutritionists formulate rations to optimize animal performance and health. This loss of nutrients consumed by birds can greatly impact the nutrients available to cattle, directly impacting animal performance and a producer’s bottom line. In 2018, Colorado researchers reported an average of 5.5% reduction in dietary net energy levels in commercial TMRs consumed by starlings compared to those with no bird presence.
    Birds have been implicated in the transmission of pathogens due to their close contact with animals. The most common way pathogens are spread from birds to livestock is the excretion of feces into cattle feed and water sources. Starlings can fly with speeds up to 45 mph and travel 20 to 30 miles each day between roosting and feeding sites, thus transporting pathogens between livestock facilities.
    The presence of high-density bird flocks at livestock facilities creates conditions ideal for the transmission of pathogens between birds and cattle. Pigeons can acquire and recirculate pathogens, including Salmonella, on dairy farms. Starlings may contribute to pathogen transmission by physically moving cattle feces containing Salmonella, E. coli or other pathogens into feed and water troughs, thereby disseminating pathogens throughout livestock facilities.
    Solutions to control bird populations by lethal methods are becoming more limited. The most common lethal method of controlling starling populations on farm is by using a compound called DRC-1339, which is the only toxin for lethal bird control currently registered by the EPA. However, this method has been under scrutiny due to the slow death of affected birds and the effects it can have on non-target species that may consume it, such as songbirds.
    Most of the species of birds that are nuisances on farms (sparrows, pigeons and starlings) are not protected under federal law. Thus, shooting and trapping are available methods to help control bird populations. However, both can be time-consuming and have safety concerns.
    The best defense is to make the farm less inviting and deter birds from coming in the first place. Clean up waste feed from outside and around bunkers so it’s not as easily accessible to birds. Seal any holes or gaps birds may use to gain access to buildings where food is plentiful.
    Strategies that deter perching in rafters or inside buildings can be used as well. Install netting in open spaces to block access to the rafters. The use of a simple mechanical device, such as sharp wire or barbs on rafters, or chemical agents that make roosting sites sticky or slippery, are common practices used to deter birds from roosting in barns. However, each of these methods can take time and money to maintain over long periods of time.
    Harassment devices are another way to deter birds from staying on a farm for an extended period. Propane exploders, hawk kites, ultrasonic sounds, pyrotechnics and others have been used extensively on farms. However, if not used at the right time of the year, effectiveness drops dramatically, and they are not long-term solutions. These devices also require a focus on safety.
    For now, the best defense against birds is to make sure food and water is not easily accessible to them. This takes a combination of cleaning, maintenance and due diligence to remove opportunities for our feathered foes to make a home on the farm. When dairy producers successfully prevent a bird invasion, they have protected the health of their cattle and the dairy’s bottom line.
    Barry Visser is a nutritionist for Vita Plus.