With summer in full swing, fighting insects at the farm can feel like a full-time job. Let’s take a closer look at three common species of flies that impact our cattle and other livestock.
The horn fly is a surprisingly small insect (the adult is only 3 to 5 mm), so it’s not the size but rather the number of these flies that causes problems. Clustering in large groups that can number in the hundreds, these flies will sit on the backs, withers and sides of cattle and pierce the skin to feed on blood.
These flies are tenacious feeders, too, taking upwards of 20 to 30 bites per fly a day.
Despite the fly’s small size, these bites are painful, so animals will move and fuss to avoid being fed upon. It is usually all for naught, though, as these flies not only feed but then also have the audacity to rest on the animal. This means a continual fly presence that is understandably highly irritating.
Just a bit smaller than the house fly, the stable fly is a ubiquitous pest in the summer. Congregating along an animal’s back, legs, sides and belly, these flies (in contrast to the horn fly) only take on average one blood meal a day. Bbut the bite is painful and causes distress.
You know the image: a cow (or horse or goat) in the summer sun with dozens of flies around its eyes and nose. This is, you guessed it, the face fly. Unlike the other two species mentioned above, these insects do not bite but instead feed on bodily secretions, most commonly tears, saliva and mucus.
They are also more likely to be found on animals on pasture, not in the barn. Although face flies don’t bite, they do transmit a common cattle disease: pink eye.
What to Do?
The three fly species above represent variations on a theme: irritants that negatively impact the health and welfare of our livestock. Animals suffering from fly infestations will constantly move to avoid the insects. This means less time grazing or resting.
Horses will stomp repeatedly to remove flies from their legs. This repetitive concussive force can cause lameness.
Cattle constantly on the move will not gain weight and, in some cases, can lose condition. Farmers may also see a negative impact on calf growth, not because the flies are feeding on the calves, but rather the cow. As the cow continuously moves to avoid the flies, the calf is unable to nurse.
Given these issues, what’s a hobby farmer to do in the summer? It’s important to realize there is no one-stop solution to controling flies on cattle and other livestock. Instead, integrated pest management (IPM) is typically the best course of action. This means cleaning up the environment (such as removing manure on a regular basis and not overcrowding the animals) in conjunction with chemical control. The latter will look different depending on an individual farm’s set up, but could include dust bags, rubs and ear tags for cattle, and face masks, fly sprays and fans for horses.
Because there are different ectoparasites out there (we haven’t even talked about ticks or grubs, just to name a few more), there should be a multi-layered plan to help control their access to your animals.