The flies buzzed and bit as husband Bruce, and I rolled out barrels of tasty fruit and vegetable scraps for the cattle. One of the most beleaguered was Creamer. Her nose was black with houseflies, and huge horseflies clung to her neck. A swish of her tail and toss of her head dislodged them for a few seconds, then the bloodsuckers settled in again. It was time to douse the herd with bug spray.
On our farm flies are more of a danger than ticks will ever be. Cattle, unlike horses, people, and dogs, do not contract Lyme disease from ticks. When covered with ticks, cattle can become anemic, but tick danger is small compared to fly danger. The risk is highest when a calf is born, and flies are abundant. Good mother cows lick their newborn calves to dry them, but even if the calf is dry, at night when dew falls, the calf will get wet.
Newborn calves, used to the constant 102-degree womb, also have difficulty warming up. Flies lay their eggs on the wet, cold calf, which is a perfect home for maggots, a condition called “flystrike.” In days, sometimes just hours, the larvae will destroy skin and burrow into the calf, depositing their toxic waste in the calf's bloodstream. If caught soon enough, the calf can be saved by clipping off the hair, then washing the calf and scraping off the maggots. In our joy at rescuing one particular calf from flystrike, we giddily named him “Marty McFly.” But if left untreated, flystrike is no joke; the calf will die.
Flies not only pester calves, but they can also cause weight-loss in cattle. Cows covered in flies spend so much of their energy swinging heads, and swishing tails to get rid of the pests they neglect their grazing.
One way to control flies is pasture management. The flies need hosts to thrive and will establish themselves in fields with livestock. Take the cows away, and the flies leave, too. Moving cattle every seven to 10 days to a new pasture will break the fly-cycle and reduce their numbers.
Another way to control the pests is fly spray. We pour repellant on the backs of our cattle every four to six weeks. I put the liquid in a plastic bottle attached to a long pole. The pole allows me to get close to skittish animals, and the bottle allows me to apply the correct dose. And while ticks are not as dangerous or annoying as flies, the repellant discourages ticks as well.
The pole method works but takes time and planning, so I'm thinking of getting a “rubbing station,” which provides on-demand repellant. The station has a pan containing tasty minerals. As the cows reach into the pan, they rub their heads against a curtain soaked with repellant. The station has a scratching bar, also soaked in repellant, which works as a back-rubber for cows with an itch. It's near the top of my must-have list, but they are pricey.
In any case, the best remedy for the summer plague of flies is a bitter-cold New Hampshire winter. My Highland cattle are a breed that hails from Scotland, where summer is not much more than a rumor. Cold weather perks them right up, and freedom from flies is their favorite part!