FROM THE PRESIDENT'S DESK: THE BIRDS ARE BACK
Every year they seem to show up at about the same time. Corn silage harvest is wrapping up, temperatures begin to drop, and suddenly there are birds everywhere. My dislike for birds on dairy farms goes back much farther than my time at Miner Institute. As a graduate student at the University of Illinois, the dairy farm had several large trees near the barns that served as roosting sites for thousands of birds, primarily starlings. During the winter after the leaves had fallen the trees still looked full from a distance. But it wasn’t foliage. It was birds.
Thousands of birds packed into bare branches. At dusk they arrived in waves, and by morning they would leave all at once. Watching that many birds rise from the trees at sunrise was both fascinating and unsettling. They were impossible to ignore. During the day, they moved constantly between feeding on ears, barns and stored feed. That was probably when I first began to appreciate that birds on dairy farms are much more than a simple annoyance. Research over the past decade has shown that they affect feed efficiency, economics, herd health, and, farm biosecurity.
At Miner Institute we see a different version of the same challenge every winter. Some mornings I watch flocks of birds lift off from around the dairy as the sun comes up. Other times I notice them feeding along the silage bunker faces, gathering around the commodity bays, or moving between feedbunks in the barns. None of this is surprising. What has changed over the years for me is how I think about birds. I used to view them primarily as a nuisance. Today, I see them as a feed management and efficiency issue.
At Miner Institute we spend a great deal of time and effort on feed quality, animal performance, and feed efficiency. We analyze forages, evaluate feed inventories, and fine-tune rations. We know that relatively small improvements in nutrition and management can have a meaningful impact on lactation performance and farm profitability. Yet during the winter months, our dairy may have hundreds or even thousands of birds consuming feed every day, and often those losses receive little attention. When we discuss shrink, we typically focus on losses during harvest, storage, and feedout that are related to our management, not necessarily those caused by birds.
We work hard to produce quality forage and preserve it in storage. Every ton of corn silage or haycrop silage represents a significant investment in seed, fertilizer, equipment, fuel, labor, and management. After harvest our goal is to preserve as much of its value as possible until it is consumed by the cow or heifer. Birds remind me that there can be additional losses after feed is exposed.
Birds spend hours feeding, picking through exposed silage, damaging bunker plastic, and moving back and forth between the silage bunkers, feed center, and barns. Over the late fall, winter, and early spring, what may seem like relatively small losses individually add up. We don’t know exactly how many pounds of feed birds consume each year at Miner Institute. What I do know is that when I watch birds move repeatedly between the bunker faces, commodity storage, and feedbunks throughout the day, it’s clear that feed losses are occurring. A survey of dairy farmers estimated that bird-related feed losses are approximately $55 per cow annually (https://doi.org/10.1371/journal.pone.0222398). For herds of any size, that represents a substantial amount of feed that never contributes to milk production. Every nutrient lost from the ration or silage bunk reduces the return on investment we made growing, harvesting, storing, and delivering that feed.
In addition to direct feed losses, birds can alter the nutritional value of the ration that remains. We spend a great deal of time trying to provide our cows with a consistent ration day after day. We monitor sorting behavior, evaluate particle size, and assess mixing procedures. Yet, birds are essentially sorting the ration before cows even touch it. And of course, the birds are selecting some of the ingredients we value most. In controlled studies (doi:10.3168/jds.2017-12858), birds preferentially consumed the higher energy portions of the ration, selecting ingredients rich in starch and fat. The result was a ration that appeared to differ nutritionally after the birds had finished feeding.
Dairy farms become attractive feeding and roosting sites for birds, especially starlings, during late fall, winter, and early spring, when food and shelter are harder to find elsewhere.
Timing matters. Researchers (https://doi.org/10.3390/birds4020018) found that starling populations on dairy farms tend to increase in the fall and remain high throughout the winter. Anyone who has tried to move birds off a farm after they have established a large roost knows how hard that can be. Addressing bird pressure early is usually easier than addressing it later.
There is no single solution for bird control. The most successful programs use an integrated approach that combines exclusion, sanitation, and deterrence. Effective bird management begins with feed management. Promptly cleaning up feed spills, maintaining tight silage covers, repairing damaged bunker plastic, and minimizing access to commodity storage areas all reduce the attractiveness of a farm to birds. Using netting, screening, or spikes to modify roosting areas within buildings, and closing unnecessary access points, such as overhead doors, can further reduce the bird population. These exclusion practices are among the most reliable long-term management tools available.
At Miner Institute we notice differences in bird numbers between our newer barns, which incorporate purposeful design elements like netting, and the older barns that provide more roosting areas near the ceilings and sidewalls. Deterrents, including lasers, noise devices, predator decoys, falconry, or strategic harassment, can be effective for certain bird species and locations. However, birds are adaptable and quickly learn which deterrents pose a real threat and which do not. Rotating deterrent strategies is often necessary to maintain effectiveness.
In my view, bird management belongs in the same conversation as forage quality, shrink, and feed efficiency. We work too hard to produce high-quality feed to give any more of it away than necessary. As bird numbers begin to increase each fall, they serve as a reminder that feed management doesn’t end at harvest. Protecting feed after it reaches storage and the feedbunk is just as important.
— Heather Dann
