Flies are enemy number one on most ranches, and with good reason. They spread diseases such as infectious bovine keratoconjunctivitis (IBK) or pink eye.
According to the University of Wisconsin, pink eye is primarily caused by the bacteria Moraxella bovis, which produces a toxin that attacks the eye. It is commonly understood that Moraxella bovis is the cause of traditional IBK or summer pink eye.
What is Pink Eye in Cattle, and What Causes it?
Pink eye is a highly contagious disease that impacts productivity and is incredibly painful to cattle. Several predisposing factors can cause it. Eyes have natural defense mechanisms against pathogens and infection, but once a scrape or abrasion occurs, the cornea can be exposed to bacteria such as Moraxella bovis.
Some predisposing factors to pink eye:
Face flies and house flies
Weeds, grass awns, seed heads, tall grass and stalks
Dust and sand
Other animals, overcrowded from heat stress and tails swishing from flies
Physical hazards, such as barbed wire or trauma during handling and transport
Pink Eye and Flies in Cattle
Traditional IBK is called summer pink eye for a reason. While IBK can happen at any time of the year, spikes more commonly occur in the summer as flies begin spreading it like wildfire.
Four primary types of flies impact cattle in the summer – horn flies, stable flies, house flies and face flies. The latter two are the ones most likely to spread pink eye.
According to University of Kentucky entomologists, face flies have sponge-like mouthparts that work by stimulating tear flow in cattle and sucking up the protein-rich secretions. They also feed on saliva, nasal discharge and blood from wounds. Face flies’ mouth parts have a sand paper like texture that irritates the eye and carry the disease from animal to animal.
Fly Control Methods for Cattle
The goal for fly control in cattle is to keep fly populations below the economic threshold, meaning, instead of 1,000-4,000 horn flies per cow, it’s suggested to keep flies below 200 per cow with fly control methods.
Various fly control programs exist today. However, with the head and eyes being a more sensitive area of the body, it is recommended to use fly control methods that can be close to the face without causing harm or self-applicators that cattle can use on their own.
Examples of these fly control methods include:
Dustbags that cattle pass under daily
Back rubbers with fly wicks
Self-applicator sprayers by mineral feeders
Ear tags
Garlic in mineral
Take note that fly resistance from chemical control methods can occur, meaning flies that survive these fly control methods go on to produce offspring that are also resistant to many of the commonly used sprays and chemicals. This is why beef producers must take a multifaceted approach to control flies and use more than one method at a time in the summer.
Garlic for Fly Control in Cattle
New research shows that feed additives such as garlic are helping cattle producers combat flies more effectively.
A Canadian research project in Saskatchewan found that adding garlic to mineral helped reduce the fly population by 50% in cow-calf herds. The research study used three cow-calf herds about two miles apart in different pastures. Two herds received a salt-mineral mix, and the other received garlic included in the mix. The cow-calf group eating the garlic had the lowest fly count.
However, buyer beware – not all garlic additives are the same. Doing your research before feeding just any garlic to your herd is essential. Some garlic additives have little to no research on their ability to repel flies and can be unpalatable to cattle. Always consult with a ruminant nutritionist or veterinarian before implementing.
Adding garlic to your mineral spring through fall and incorporating other fly control methods is recommended.
Ralco Mineral with Garlic Solutions
Ralco ruminant nutritionists have put the work into researching effective garlic solutions for farmers and ranchers. Ralco’s Rumatec™ Cow-Calf Mineral line-up now includes Garlium options, a proven garlic additive that helps repel flies and ticks, to help beef producers effectively manage pests. As animals ingest this highly palatable additive, the garlic odor is excreted through their skin and respiratory system to help keep pests away and help manage pink eye.