Jim Moseley, Dairy Nutritionist
It’s time once again to consider fly control options. Flies are not just irritating to cows; they transmit disease, reduce feed intake, and significantly reduce profitability. Heavy fly infestations have been shown to reduce milk yield by as much as 15%. Most often, the stress that cows are subjected to by flies is compounded by the effect of hot, humid weather. If you’ve been bitten by a fly, imagine what it would be like to be bitten hundreds of times. It has been estimated that horn flies alone can suck 1 to 2 gallons of blood per cow per year. It’s no wonder that we see cows bunched up in a corner or running to avoid these pests.
It is recommended that an Integrated Pest Management (IPM) control system be implemented. This is an approach that uses a number of complementary practices:
- Keep buildings free of organic debris where flies can breed.
- Keep cattle areas as clean and dry as possible. Flies lay eggs in manure, decaying silage, spilled feed, and soiled bedding.
- Keep calf hutches clean, well ventilated, and moved between calves.
- Keep feed storage areas, bunks, and waterers clean and in good repair.
- Keep grass and weeds around barns, feeders, and hutches cut.
- Use non-insecticidal controls such as sticky traps.
- Use chemical controls including baits and sprays.
- Use larvicide controls. This is where we fit in. Adding larvicide to our feeds provides a needed service and adds unique value to our products.
A larvicide is a unique chemical compound that when fed in very small concentrations to calves, heifers, lactating, and non-lactating cows; passes through the digestive tract and remains in the manure. It is neither digested nor absorbed from the tract. As larvae hatch from fly eggs that adult flies have deposited in the manure, they consume organic matter and larvicide. Our most popular fly control product is ClariFly® Larvicide. When larvae consume or come in contact with Diflubenzuron†, the active ingredient in ClariFly®, the deposition of chitin into their exoskeleton is inhibited. Without an exoskeleton, the larvae die and don’t develop into breeding adult flies that can bother dairy animals. ClariFly® therefore prevents the emergence of house, stable, face, and horn flies from the manure of treated animals. To be most effective, ClariFly® should be added to feeds in early spring before flies begin to appear, and continued through the summer and into the fall, until cold weather reduces or ends fly activity. If feeding is started too late, untreated manure will offer a breeding ground for flies.
Starting in the early spring, Kent Nutrition Group adds ClariFly® to our most popular lines of Calf Starters and Milk Formulas. ClariFly® can also be added to custom calf, heifer, dry cow, and lactating feeds when requested, and meets regulatory requirements.
In addition to ClariFly®, Kent Nutrition Group also offers Altosid® Insect Growth Regulator (IGR) in various products that meet strict regulatory requirements for cattle on pasture. Unlike ClariFly®, Altosid® IGR will not harm dung beetle larvae that are largely responsible for the breakdown of pasture manure. Its active ingredient, (S)-Methoprene, passes through the cow, remaining in the manure. There, it mimics naturally occurring insect biochemicals that are responsible for insect development. It breaks the horn fly life cycle by preventing their larvae from developing into adults that bite.
ClariFly® and Altosid® IGR are considered to be safe for cows, humans, and the environment. For just pennies per cow per day, significant gains in milk production can be achieved. However, to reach maximum gains; these should be part of an IPM system.